FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Posa, F Ventura, B Notarnicola, C Casarano, D Di Rosa, D Preziosa, G AF Posa, Francesco Ventura, Bartolomeo Notarnicola, Claudia Casarano, Domenico Di Rosa, Daniela Preziosa, Giovanni CA Cassini Radar Sci Team TI Synergic use of electromagnetic models and SAR images for the geophysical parameters estimation of Earth and Titan surface SO RIVISTA ITALIANA DI TELERILEVAMENTO LA English DT Article DE SAR images; geophysical parameters; electromagnetic models ID CASSINI RADAR; SCATTERING; SIMULATION; MAPPER AB This work identifies two applications of the microwave sensors in combination with electromagnetic models. In the first case, multi-polarization and multi-frequency SAR images have been used in synergy with optical Images in order to obtain soil moisture and vegetation water content maps for vegetated areas. In the second case, radar data from the Cassini radar (Ku band) have been analysed in order to infer physical and morphological of selected features of Titan's surface. Scattering properties of lake-like features, supposedly of liquid hydrocarbons, are discussed, and geometric parameters of wind-generated "sand dunes" are estimated. C1 [Posa, Francesco; Ventura, Bartolomeo; Notarnicola, Claudia; Di Rosa, Daniela; Preziosa, Giovanni] Politecn Bari, Dip Interateneo Fis, I-70126 Bari, Italy. [Notarnicola, Claudia] Inst Appl Remote Sensing, EURAC, I-39100 Bolzano, Italy. [Casarano, Domenico] CNR, IRPI, I-70126 Bari, Italy. [Cassini Radar Sci Team] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Posa, F (reprint author), Politecn Bari, Dip Interateneo Fis, I-70126 Bari, Italy. EM claudia.notarnicola@eurac.edu NR 21 TC 1 Z9 1 U1 0 U2 2 PU ASSOC ITALIANA TELERILEVAMENTO PI FIRENZE PA UNIV DEGLI STUDI FIRENZE, DIPT SCI TERRA, VIA JACOPO NARDI, FIRENZE, 50132, ITALY SN 1129-8596 J9 RIV ITAL TELERILEVAM JI Riv. Ital. Telerilevamento PY 2008 VL 40 IS 2 BP 89 EP 102 PG 14 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 402DO UT WOS:000262994600009 ER PT B AU Barry, RK Mukai, K Sokoloski, JL Danchi, WC Hachisu, I Evans, A Gehrz, R Mikolajewska, J AF Barry, R. K. Mukai, K. Sokoloski, J. L. Danchi, W. C. Hachisu, I. Evans, A. Gehrz, R. Mikolajewska, J. BE Evans, A Bode, MF OBrien, TJ Darnley, MJ TI On the Distance of RS Ophiuchi SO RS OPHIUCHI (2006) AND THE RECURRENT NOVA PHENOMENON SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on RS Ophiuchi (2006) and the Recurrent Nova Phenomenon CY JUN 12-14, 2007 CL Keele Univ, Keele, ENGLAND SP Res Inst Environm, Phys Sci & Appl Math, Astrophys Res Inst, Liverpool John Moores Univ, Royal Astron Soc HO Keele Univ ID DIFFUSIVE SHOCK ACCELERATION; RECURRENT NOVA; 2006 OUTBURST; COSMIC-RAYS; ABSORPTION; ROTATION; DECLINE; GIANTS; SHELLS; STARS AB An unprecedented array of astronomical observatories were brought to bear on the 2006 outburst of RS Ophiuchi. Many calculations and values derived from these measurements are sensitive to the distance. Historically, the distance to RS Oph has fallen in the range 0.5 to >5 kpc with distances in the low end of this range asserted during later epochs. We survey the literature prior to 2006 and review the various approaches taken to determine distances. We report discussion of this issue from the current epoch and make recommendations for further measurements and calculations to bound the distance. Lastly, we report that for the 2006 outburst, the canonical distance is 1.4(-0.2)(+0.6) kpc. C1 [Barry, R. K.; Danchi, W. C.] NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. RP Barry, RK (reprint author), NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. RI Hachisu, Izumi/F-2713-2017 OI Hachisu, Izumi/0000-0002-0884-7404 NR 51 TC 15 Z9 15 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-674-5 J9 ASTR SOC P PY 2008 VL 401 BP 52 EP 60 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BIV00 UT WOS:000262980000006 ER PT B AU Mukai, K AF Mukai, Koji BE Evans, A Bode, MF OBrien, TJ Darnley, MJ TI RS Ophiuchi in Quiescence: Why is it X-ray Faint? SO RS OPHIUCHI (2006) AND THE RECURRENT NOVA PHENOMENON SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on RS Ophiuchi (2006) and the Recurrent Nova Phenomenon CY JUN 12-14, 2007 CL Keele Univ, Keele, ENGLAND SP Res Inst Environm, Phys Sci & Appl Math, Astrophys Res Inst, Liverpool John Moores Univ, Royal Astron Soc HO Keele Univ ID CATACLYSMIC VARIABLES; RECURRENT NOVAE; ACCRETION DISKS; 2006 OUTBURST; WHITE-DWARFS; EMISSION; SYSTEMS; ROSAT; WAVE AB The short interval between successive outbursts of RS Oph strongly suggests that it has a high-mass white dwarf accreting at a high rate. This, in turn, suggests the possibility of prominent X-ray emission from RS Oph in quiescence. However, archival quiescent X-ray observations of RS Oph show it to be a modest soft X-ray source, but not a strong 2-10 keV X-ray source. In this aspect, RS Oph differs markedly from T CrB. We speculate on the possible mechanisms that could significantly suppress the 2-10 keV X-ray emission in RS Oph. C1 NASA, Goddard Space Flight Ctr, CRESST, Greenbelt, MD 20771 USA. RP Mukai, K (reprint author), NASA, Goddard Space Flight Ctr, CRESST, Greenbelt, MD 20771 USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-674-5 J9 ASTR SOC P PY 2008 VL 401 BP 84 EP 88 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BIV00 UT WOS:000262980000009 ER PT B AU Barry, RK Danchi, WC AF Barry, Richard K. Danchi, William C. BE Evans, A Bode, MF OBrien, TJ Darnley, MJ TI High-resolution Interferometric Observations of Nova RS Ophiuchi and a Proposed Unification Model for Persistent Dust Creation in Recurrent Novae SO RS OPHIUCHI (2006) AND THE RECURRENT NOVA PHENOMENON SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on RS Ophiuchi (2006) and the Recurrent Nova Phenomenon CY JUN 12-14, 2007 CL Keele Univ, Keele, ENGLAND SP Res Inst Environm, Phys Sci & Appl Math, Astrophys Res Inst, Liverpool John Moores Univ, Royal Astron Soc HO Keele Univ ID CIRCUMSTELLAR ENVELOPES; SYSTEMS; STARS AB We review observations of nova RS Ophiuchi using long-baseline near-infrared and mid-infrared interferometry at three observatories: the Keck Interferometer in the Nulling mode (KIN), the Palomar Testbed Interferometer (PTI), and the Infrared and Optical Telescope Array (IOTA). We discuss these observations in the context. of a unifying model of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. We discuss how recent observations using the Spitzer Space Telescope and the VLTI support this proposed model. C1 [Barry, Richard K.; Danchi, William C.] NASA, Goddard Space Flight Ctr, Lab Exoplanets & Stellar Astrophys, Greenbelt, MD 20771 USA. RP Barry, RK (reprint author), NASA, Goddard Space Flight Ctr, Lab Exoplanets & Stellar Astrophys, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-674-5 J9 ASTR SOC P PY 2008 VL 401 BP 235 EP 238 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BIV00 UT WOS:000262980000033 ER PT B AU Skinner, G Senziani, F Jean, P Hernanz, M AF Skinner, Gerry Senziani, Fabio Jean, Pierre Hernanz, Margarita BE Evans, A Bode, MF OBrien, TJ Darnley, MJ TI The Use of the BAT Instrument on Swift for the Detection of Prompt Gamma-Ray Emission from Novae SO RS OPHIUCHI (2006) AND THE RECURRENT NOVA PHENOMENON SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on RS Ophiuchi (2006) and the Recurrent Nova Phenomenon CY JUN 12-14, 2007 CL Keele Univ, Keele, ENGLAND SP Res Inst Environm, Phys Sci & Appl Math, Astrophys Res Inst, Liverpool John Moores Univ, Royal Astron Soc HO Keele Univ ID BURST ALERT TELESCOPE; SPECTROMETER OBSERVATIONS; CLASSICAL NOVAE; RS-OPHIUCHI; MISSION; LINES; SKY AB Gamma-rays are expected to be emitted during and immediately following a nova explosion due to the annihilation of positrons emitted by freshly produced short-lived radioactive isotopes. The expected gamma-ray emission is relatively short-lived and as nova explosions are unpredictable, the best chance of detecting the gamma-rays is with a wide field instrument. At the time when the flux is expected to reach its peak, most of the gamma-ray production is at depths such that the photons suffer several Compton scatterings before escaping, degrading their energy down to the hard X-ray band (10s of keV). SWIFT/BAT is a very wide field coded mask instrument working in the energy band 14-190 keV and so is very well suited to the search for such gamma-rays. A retrospective search is being made in the BAT data for evidence for gamma-ray emission from the direction of novae at around the time of their explosion. So far the only positive detection is of RS Ophiuchi and in this case the emission is probably due to shock heating. C1 [Skinner, Gerry] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Skinner, G (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. RI Hernanz, Margarita/K-1770-2014 OI Hernanz, Margarita/0000-0002-8651-7910 NR 12 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-674-5 J9 ASTR SOC P PY 2008 VL 401 BP 318 EP 322 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BIV00 UT WOS:000262980000049 ER PT J AU Kharuk, VI Dvinskaya, ML Im, ST Ranson, KJ AF Kharuk, V. I. Dvinskaya, M. L. Im, S. T. Ranson, K. J. TI Tree vegetation of the forest-tundra ecotone in the Western Sayan mountains and climatic trends SO RUSSIAN JOURNAL OF ECOLOGY LA English DT Article DE climatic trends; mountain forest-tundra ecotone; Pinus sibirica ID SWEDISH SCANDES; STANDS; ALASKA AB Parameters of reproduction of the Siberian stone pine (Pinus sibirica), including radial and apical tree increments, the age structure of stands, the amount of young growth, and its distribution along an altitudinal gradient, have been studied in the forest-tundra ecotone of the Western Sayan. The results show that, over the past 30 years, P. sibirica undergrowth has expanded to the mountain tundra belt, the apical and radial tree increments and stand density have increased, and the life form of many P. sibirica plants has changed from prostrate to erect (single-or multistemmed). These changes correlate with the dynamics of summer temperatures and monthly (in May and June) and annual precipitation. The rise of summer temperatures by 1 degrees C promotes the expansion of P. sibirica undergrowth for approximately 150 m up the altitudinal gradient. C1 [Kharuk, V. I.; Dvinskaya, M. L.; Im, S. T.] Russian Acad Sci, Siberian Branch, Sukachev Inst Forest, Krasnoyarsk 630036, Russia. [Ranson, K. J.] NASA, Goddard Space Ctr, Washington, DC 20546 USA. RP Kharuk, VI (reprint author), Russian Acad Sci, Siberian Branch, Sukachev Inst Forest, Krasnoyarsk 630036, Russia. EM kharuk@ksc.krasn.ru; jon@taiga.gsfc.nasa.gov RI Ranson, Kenneth/G-2446-2012; Im, Sergei/J-2736-2016 OI Ranson, Kenneth/0000-0003-3806-7270; Im, Sergei/0000-0002-5794-7938 NR 25 TC 12 Z9 15 U1 0 U2 4 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 1067-4136 J9 RUSS J ECOL+ JI Russ. J. Ecol. PD JAN PY 2008 VL 39 IS 1 BP 8 EP 13 DI 10.1134/S1067413608010025 PG 6 WC Ecology SC Environmental Sciences & Ecology GA 255YS UT WOS:000252695100002 ER PT S AU Klimesh, MA Moision, B AF Klimesh, Matthew A. Moision, Bruce BE Huang, B Heymann, RW SerraSagrista, J TI Onboard Data Compression of Synthetic Aperture Radar Data: Status and Prospects SO SATELLITE DATA COMPRESSION, COMMUNICATION, AND PROCESSING IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Satellite Data Compression, Communications, and Archiving IV CY AUG 10-11, 2008 CL San Diego, CA SP SPIE DE Data compression; synthetic aperture radar; SAR ID SAR RAW DATA; TRELLIS-CODED QUANTIZATION AB Synthetic aperture radar (SAR) instruments on spacecraft are capable of producing huge quantities of data. Onboard lossy data compression is commonly used to reduce the burden on the communication link. In this paper air overview is given of various SAR data compression techniques, along with ail assessment of how much improvement is possible (and practical) and how to approach the problem of obtaining it. C1 [Klimesh, Matthew A.; Moision, Bruce] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Klimesh, MA (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. EM matthew.a.klimesh@jpl.nasa.gov; bruce.e.moision@jpl.nasa.gov NR 16 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7304-2 J9 P SOC PHOTO-OPT INS PY 2008 VL 7084 AR UNSP 70840P DI 10.1117/12.800822 PG 6 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics; Telecommunications SC Computer Science; Engineering; Instruments & Instrumentation; Optics; Telecommunications GA BIZ47 UT WOS:000263957400021 ER PT J AU Fu, R Hu, L Gu, GJ Li, YD AF Fu Rong Hu Liang Gu GuoJun Li YaoDong TI A comparison study of summer-time synoptic-scale waves in South China and the Yangtze River basin using the TRMM Multi-Satellite Precipitation Analysis daily product SO SCIENCE IN CHINA SERIES D-EARTH SCIENCES LA English DT Article DE TRMM; 3-dimensional spectrum analysis; synoptic-scale waves; South China; Yangtze River basin ID SATELLITE; DISTURBANCES; BRIGHTNESS; SPECTRA AB Summer-time synoptic-scale waves in South China and the Yangtze River basin are quantified and compared by means of analyzing the 6-year (1998-2004) TRMM Multi-Satellite Precipitation Analysis (TMPA) daily product. An innovative 3-dimensional spectrum analysis method is applied. The results indicate that synoptic-scale waves appearing in South China prominently propagate westward within a zonal wavenumber range of 9-21 and a frequency range of -0.12--0.22 cycles day(-1)supercript stop, while those in the Yangtze River basin primarily move eastward with the same characteristic wavenumbers of 9-21, but within a frequency range of 0.2-0.29 cycles day(-1). Zonal and meridional distributions, and seasonal variations of these waves are further explored and compared. It shows that summer-time synoptic-scale waves in the South China result from the northward migration and oscillation of the Intertropical Convergence Zone (ITCZ) in the western Pacific, whereas the ones in the Yangtze River basin are generally related to the synoptic troughs within the westerly flow, originating from the Qinghai-Tibet Plateau. C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Chinese Acad Sci, Inst Atmospher Phys, Beijing 100029, Peoples R China. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Fu, R (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. NR 27 TC 2 Z9 6 U1 0 U2 4 PU SCIENCE CHINA PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 1006-9313 J9 SCI CHINA SER D JI Sci. China Ser. D-Earth Sci. PD JAN PY 2008 VL 51 IS 1 BP 114 EP 122 DI 10.1007/s11430-007-0125-6 PG 9 WC Geosciences, Multidisciplinary SC Geology GA 237YM UT WOS:000251412300011 ER PT S AU Thompson, DJ AF Thompson, D. J. CA Fermi Large Area Telescope Coll BE Bastieri, D Rando, R TI Multiwavelength Opportunities for GeV and TeV Telescopes SO SCIENCE WITH THE NEW GENERATION OF HIGH ENERGY GAMMA-RAY EXPERIMENTS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 6th Workshop on High Energy Gamma-Ray Experiments CY OCT 08-10, 2008 CL Abano Terme, ITALY SP Univ Padova, Natl Inst Nucl Phys, Sect Padova DE gamma-ray telescopes; multiwavelength AB With AGILE and Fermi now in orbit and TeV telescopes continuing to improve their performance, a variety of multiwavelength opportunities is increasingly available. One goal of such programs is to take advantage of the complementary capabilities of the two types of telescopes: the wide field surveys of the satellite detectors and the high sensitivity and resolution of the ground-based telescopes. Some aspects of these multiwavelength efforts will be carried out in near-real-time but must be anticipated with advance preparation. These include gamma-ray burst follow-ups and flare campaigns. Other projects such as long-term variability studies and gamma-ray source identification require deep observations and cooperative work with astrophysicists at longer wavelengths, along with the theoretical studies that tie the observations together. C1 [Thompson, D. J.; Fermi Large Area Telescope Coll] NASA, Goddard Space Flight Ctr, Astroparticle Phys Lab, Greenbelt, MD 20771 USA. RP Thompson, DJ (reprint author), NASA, Goddard Space Flight Ctr, Astroparticle Phys Lab, Greenbelt, MD 20771 USA. RI Thompson, David/D-2939-2012 OI Thompson, David/0000-0001-5217-9135 NR 5 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0649-0 J9 AIP CONF PROC PY 2008 VL 1112 BP 1 EP 7 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJK68 UT WOS:000266714100001 ER PT J AU Hernandez, O Chapman, B Jin, HQ AF Hernandez, Oscar Chapman, Barbara Jin, Haoqiang TI A performance tuning methodology with compiler support SO SCIENTIFIC PROGRAMMING LA English DT Article DE Compiler optimizations; performance tuning methodology; feedback directed optimizations; performance tools AB We have developed an environment, based upon robust, existing, open source software, for tuning applications written using MPI, OpenMP or both. The goal of this effort, which integrates the OpenUH compiler and several popular performance tools, is to increase user productivity by providing an automated, scalable performance measurement and optimization system. In this paper we describe our environment, show how these complementary tools can work together, and illustrate the synergies possible by exploiting their individual strengths and combined interactions. We also present a methodology for performance tuning that is enabled by this environment. One of the benefits of using compiler technology in this context is that it can direct the performance measurements to capture events at different levels of granularity and help assess their importance, which we have shown to significantly reduce the measurement overheads. The compiler can also help when attempting to understand the performance results: it can supply information on how a code was translated and whether optimizations were applied. Our methodology combines two performance views of the application to find bottlenecks. The first is a high level view that focuses on OpenMP/MPI performance problems such as synchronization cost and load imbalances; the second is a low level view that focuses on hardware counter analysis with derived metrics that assess the efficiency of the code. Our experiments have shown that our approach can significantly reduce overheads for both profiling and tracing to acceptable levels and limit the number of times the application needs to be run with selected hardware counters. In this paper, we demonstrate the workings of this methodology by illustrating its use with selected NAS Parallel Benchmarks and a cloud resolving code. C1 [Hernandez, Oscar; Chapman, Barbara] Univ Houston, Dept Comp Sci, Houston, TX 77204 USA. [Jin, Haoqiang] NASA, Ames Res Ctr, Adv Supercomp Div, Moffett Field, CA 94035 USA. RP Hernandez, O (reprint author), Univ Houston, Dept Comp Sci, Houston, TX 77204 USA. EM oscar@cs.uh.edu; chapman@cs.uh.edu; hjin@nas.nasa.gov FU National Science Foundation [CCF-0444468, CCF-0702775] FX This work was supported by the National Science Foundation, under contracts CCF-0444468 and CCF0702775. We would like to thank our partners in the Copper Project: Felix Wolf, Shirley Moore, Rick Kufrin and Danesh Tafti for providing valuable feedback on how to improve and design the environment. We would also like to thank Bob Hood and Davin Chang from CSC at Nasa Ames for providing us access to their Altix systems to perform the experiments reported on here. NR 29 TC 0 Z9 0 U1 0 U2 1 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 1058-9244 J9 SCI PROGRAMMING-NETH JI Sci. Program. PY 2008 VL 16 IS 2-3 BP 135 EP 153 DI 10.3233/SPR-2008-0253 PG 19 WC Computer Science, Software Engineering SC Computer Science GA 525OW UT WOS:000272226800004 ER PT B AU Bregman, JD Bregman, JN Temi, P AF Bregman, Jesse D. Bregman, Joel N. Temi, Pasquale BE Chary, RR Teplitz, HI Sheth, K TI Unusual PAH emission in elliptical galaxies SO SECOND ANNUAL SPITZER SCIENCE CENTER CONFERENCE: INFRARED DIAGNOSTICS OF GALAXY EVOLUTION SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT 2nd Annual Spitzer Science Center Conference on Infrared Diagnostics of Galaxy Evolution CY NOV 14-16, 2005 CL Pasadena, CA ID SPACE-TELESCOPE AB In a sample of thirty normal elliptical galaxies observed with the Spitzer IRS, one galaxy, NGC4697, shows strong PAH emission, but with an apparently weak 7.7 mu m feature. We find that the PAH emission is confined to the central regions of the galaxy and that once a quiescent elliptical galaxy spectrum is subtracted, the PAH feature ratios are normal. We show that the PAH spectrum resembles the diffuse ISM of our galaxy rather than an HII region, and is not indicative of a starburst galaxy. We suggest that the PAHs in NGC4697 are consistent with a recent but now past burst of star formation. C1 [Bregman, Jesse D.; Temi, Pasquale] NASA, Ames Res Ctr, Astrophys Branch, MS 245-6, Moffett Field, CA 94035 USA. [Bregman, Joel N.] Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. [Temi, Pasquale] SETI Inst, Mountain View, CA 94043 USA. [Temi, Pasquale] Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. RP Bregman, JD (reprint author), NASA, Ames Res Ctr, Astrophys Branch, MS 245-6, Moffett Field, CA 94035 USA. FU Spitzer Science Center and NASA FX We wish to thank the Spitzer Science Center and NASA for making available the support and observing time that made this project possible, and Dr. A. Tielens for valuable discussions. NR 7 TC 8 Z9 8 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-325-6 J9 ASTR SOC P PY 2008 VL 381 BP 34 EP + PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHO46 UT WOS:000254828200006 ER PT B AU Staguhn, J Morris, M Uchida, K Benford, D Bertoldi, F AF Staguhn, Johannes Morris, Mark Uchida, Keven Benford, Dominic Bertoldi, Frank BE Chary, RR Teplitz, HI Sheth, K TI Dust emission from a large scale shock near the Galactic Center SO SECOND ANNUAL SPITZER SCIENCE CENTER CONFERENCE: INFRARED DIAGNOSTICS OF GALAXY EVOLUTION SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT 2nd Annual Spitzer Science Center Conference on Infrared Diagnostics of Galaxy Evolution CY NOV 14-16, 2005 CL Pasadena, CA AB AFGL5376 is a prominent 25 mu m source near the Galactic Center produced by a large scale (similar to 100 pc) shock that extends well above the Galactic plane. This shock region coincides with the edge of a vertical radio continuum feature, which appears to be at the surface of a 150-pc lobe that encompasses the Galactic center. There is no evidence for nearby star formation. The unusually warm (T similar to 100 K) dust emission peak, traced by the 25 mu m emission, is clearly surrounded by high velocity (CO)-C-12(2-1) emission. We are currently conducting a comprehensive observing study of the region including Spitzer IRS and MIPS observations. Our continuum observations are aimed at allowing the derivation of mass and temperature distribution at sub-parsec resolution. Here we present MIPS 24 mu m observations in combination with MAMBO observations at 1.2 mm wavelength. The latter reveal the presence of strong millimeter continuum emission in the vicinity of AFGL5376. We present a first estimate of the masses of the cold molecular clouds that are associated with this region. Our complete set of continuum Spitzer and (sub-) millimeter emission measurements together with our IRS spectroscopy will be used later to constrain magnetohydrodynamic models for the production of this highly energetic feature. C1 [Staguhn, Johannes; Benford, Dominic] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Staguhn, Johannes] SSAI, Lanham, MD 20706 USA. [Morris, Mark] Univ Calif Los Angeles, Div Astron & Astrophys, Los Angeles, CA 90095 USA. [Uchida, Keven] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. [Bertoldi, Frank] Univ Bonn, D-53121 Bonn, Germany. RP Staguhn, J (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012 OI Benford, Dominic/0000-0002-9884-4206 NR 5 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-325-6 J9 ASTR SOC P PY 2008 VL 381 BP 84 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHO46 UT WOS:000254828200016 ER PT B AU Xu, CK Appleton, PN Dopita, M Gao, Y Lu, NY Popescu, C Reach, WT Sulentic, J Tuffs, R Yun, M AF Xu, C. K. Appleton, P. N. Dopita, M. Gao, Y. Lu, N. Y. Popescu, C. Reach, W. T. Sulentic, J. Tuffs, R. Yun, M. BE Chary, RR Teplitz, HI Sheth, K TI Spitzer observations of Stephan's Quintet - IGM dust and gas in a multi-galaxy collision SO SECOND ANNUAL SPITZER SCIENCE CENTER CONFERENCE: INFRARED DIAGNOSTICS OF GALAXY EVOLUTION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Annual Spitzer Science Center Conference on Infrared Diagnostics of Galaxy Evolution CY NOV 14-16, 2005 CL Pasadena, CA AB Stephan's Quintet (SQ) is the most famous and well studied compact group of galaxies. Spectacular activity is triggered by interactions between member galaxies and various constituents of the intragroup medium (IGM), including a 40 kpc large scale-shock and IGM starbursts more than 20 kpc away from any neighboring galaxy centers. Our new Spitzer IRS (SH, LH, and SL) and MIPS (70 mu m and 160 mu m) observations of SQ with unprecedented resolution and sensitivity give new constraints on the physical conditions of the IGM gas and dust. In particular, our IRS observations discovered very strong pure MIR emission lines of molecular hydrogen in the SQ shock, the first time such a spectrum is detected in an extragalactic source. And the MIPS 160 mu m map of SQ shows clear evidence for the diffuse IGM dust emission. C1 [Xu, C. K.] NASA, Herschel Sci Ctr, Pasadena, CA 91125 USA. RP Xu, CK (reprint author), NASA, Herschel Sci Ctr, 100-22 Caltech, Pasadena, CA 91125 USA. RI Dopita, Michael/P-5413-2014 OI Dopita, Michael/0000-0003-0922-4986 NR 8 TC 2 Z9 2 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-325-6 J9 ASTR SOC P PY 2008 VL 381 BP 88 EP 91 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHO46 UT WOS:000254828200017 ER PT B AU Benford, DJ Staguhn, JG AF Benford, Dominic J. Staguhn, Johannes G. BE Chary, RR Teplitz, HI Sheth, K TI Dust distribution in the spiral galaxy M51 SO SECOND ANNUAL SPITZER SCIENCE CENTER CONFERENCE: INFRARED DIAGNOSTICS OF GALAXY EVOLUTION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Annual Spitzer Science Center Conference on Infrared Diagnostics of Galaxy Evolution CY NOV 14-16, 2005 CL Pasadena, CA AB We present the analysis of far-infrared imaging of the nearby grand design spiral galaxy M51. Being close enough for the spiral structure to be resolved, it is possible to determine the dust temperature and distribution as a function of galactocentric radius. Using Spitzer/MIPS data at 70 mu m and 160 mu m in concert with a deep 350 mu m image taken with the Submillimeter High Angular Resolution Camera (SHARC-II) at the Caltech Submillimeter Observatory (CSO), we have mapped the dust emission. Additional SCUBA 850 mu m data help determine the overall dust spectrum. We derive the nuclear and spiral arm dust mass and temperatures (30 K in the nucleus, 25 K in the disk) and measure the emissivity index (beta = 1.3). C1 [Benford, Dominic J.; Staguhn, Johannes G.] NASA, Goddard Space Flight Ctr, Observ Cosmol Lab, Greenbelt, MD 20771 USA. RP Benford, DJ (reprint author), NASA, Goddard Space Flight Ctr, Observ Cosmol Lab, Code 665, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012 OI Benford, Dominic/0000-0002-9884-4206 NR 4 TC 2 Z9 2 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-325-6 J9 ASTR SOC P PY 2008 VL 381 BP 132 EP 135 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHO46 UT WOS:000254828200024 ER PT B AU Buchanan, CL Kastner, JH Forrest, WJ Hrivnak, BJ Sahai, R Egan, M Frank, A Barnbaum, C AF Buchanan, Catherine L. Kastner, Joel H. Forrest, William J. Hrivnak, Bruce J. Sahai, Raghvendra Egan, Michael Frank, Adam Barnbaum, Cecilia BE Chary, RR Teplitz, HI Sheth, K TI Spitzer IRS spectra of luminous 8 mu m sources in the large magellanic cloud SO SECOND ANNUAL SPITZER SCIENCE CENTER CONFERENCE: INFRARED DIAGNOSTICS OF GALAXY EVOLUTION SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT 2nd Annual Spitzer Science Center Conference on Infrared Diagnostics of Galaxy Evolution CY NOV 14-16, 2005 CL Pasadena, CA ID INFRARED SPECTROGRAPH IRS AB We have produced an atlas of Spitzer Infrared Spectrograph (IRS) spectra of mass-losing, evolved stars in the Large Magellanic Cloud. These stars were selected to have high mass-loss rates and so contribute significantly to the return of processed materials to the ISM. Our high-quality spectra enable the determination of the chemistry of the circumstellar envelope from the mid-IR spectral features and continuum. We have classified the spectral types of the stars and show that the spectral types separate clearly in infrared color-color diagrams constructed from 2MASS data and synthetic IRAC/MIPS fluxes derived from our IRS spectra. We present diagnostics to identify and classify evolved stars in nearby galaxies with high confidence levels using Spitzer and 2MASS photometry. Comparison of the spectral classes determined using IRS data with the IR types assigned based on NIR colors also revealed a significant number of mis-classifications and enabled us to refine the NIR color criteria resulting in more accurate NIR color classifications of dust-enshrouded objects. C1 [Buchanan, Catherine L.; Kastner, Joel H.] Rochester Inst Technol, Ctr Imaging Sci, 54 Lomb Mem Dr, Rochester, NY 14623 USA. [Forrest, William J.; Frank, Adam] Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. [Hrivnak, Bruce J.] Valparaiso Univ, Dept Phys & Astron, Valparaiso, IN 46383 USA. [Sahai, Raghvendra] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Egan, Michael] AF Res Lab, OASD, Arlington, VA 22202 USA. [Barnbaum, Cecilia] Valdosta State Coll, Valdosta, GA 31698 USA. RP Buchanan, CL (reprint author), Rochester Inst Technol, Ctr Imaging Sci, 54 Lomb Mem Dr, Rochester, NY 14623 USA. EM clbsps@cis.rit.edu; jhk@cis.rit.edu FU NASA; Jet Propulsion Laboratory to Cornell University [960803]; California Institute of Technology [960803] FX The design, fabrication, and testing of the IRS at Ball Aerospace Corporation was supported by a NASA contract awarded by the Jet Propulsion Laboratory to Cornell University (JPL contract number 960803). The IRS pipeline was developed at the SSC at the California Institute of Technology under contract to JPL. NR 6 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-325-6 J9 ASTR SOC P PY 2008 VL 381 BP 140 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHO46 UT WOS:000254828200026 ER PT B AU Pope, A Scott, D Dickinson, M Chary, RR Morrison, G Borys, C Sajina, A AF Pope, Alexandra Scott, Douglas Dickinson, Mark Chary, Ranga-Ram Morrison, Glenn Borys, Colin Sajina, Anna BE Chary, RR Teplitz, HI Sheth, K TI Using Spitzer to probe the nature of submillimeter galaxies in GOODS-N SO SECOND ANNUAL SPITZER SCIENCE CENTER CONFERENCE: INFRARED DIAGNOSTICS OF GALAXY EVOLUTION SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT 2nd Annual Spitzer Science Center Conference on Infrared Diagnostics of Galaxy Evolution CY NOV 14-16, 2005 CL Pasadena, CA ID SCUBA SUPER-MAP; EVOLUTION; IDENTIFICATIONS; CONSTRAINTS; REDSHIFTS AB How does the submm galaxy population detected by SCUBA fit into galaxy evolution? How do these rare starbursting systems, which contribute significantly to high redshift star-formation, relate to other galaxy populations? Deep radio observations have been most useful for studying these systems, but still leave a significant fraction of the population unidentified. Now with the deep IRAC and MIPS images from the GOODS Spitzer Legacy program and a re-analysis of the deep radio data, we are able to identilv counterparts for a large fraction of SCUBA galaxies in GOODS-N. All of these counterparts are detected by Spitzer. Given the vast multi-wavelength data in this field, we can study the spectral energy distributions (SEDs) of these systems and determine what is fueling their intense infrared luminosities. A rest-frame composite optical-to-radio SED for all spectroscopically identified submm sources shows that the average SCUBA galaxy is consistent with models of ultraluminous starburst galaxies, although cooler than those observed locally. Because of this, the submm flux alone consistently overestimates L-IR when using spectral templates which obey the local ULIRG temperature-luminosity relation. The wide range of 24/850 micron flux ratios as a function of redshift indicates the presence of strong mid-IR features, to be confirmed with deep IRS spectroscopy. The IRAC colours of the submm systems provide useful redshift constraints, since, at these redshifts, IRAC samples the stellar bump. The Spitzer photometry of this large sample of submm galaxies has allowed us to put constraints on many of the outstanding issues in submm. astronomy. C1 [Pope, Alexandra; Scott, Douglas] Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. [Dickinson, Mark] Natl Opt Astron Observ, Tucson, AZ 85719 USA. [Chary, Ranga-Ram; Sajina, Anna] Spiter Sci Ctr, Pasadena, CA 91125 USA. [Borys, Colin] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. [Borys, Colin] NASA, Herschel Sci Ctr, Pasadena, CA 91125 USA. RP Pope, A (reprint author), Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. NR 17 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-325-6 J9 ASTR SOC P PY 2008 VL 381 BP 249 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHO46 UT WOS:000254828200048 ER PT B AU Seymour, N Stern, D De Breuck, C Vernet, J Fosbury, R Rettura, A Zirm, A Rocca-Volmerange, B Lacy, M Teplitz, H Dey, A Dickinson, A van Brengel, W Miley, G Rottgering, H Eisenhardt, P McCarthy, P De Breuck, F Vernet, L AF Seymour, N. Stern, D. De Breuck, C. Vernet, J. Fosbury, R. Rettura, A. Zirm, A. Rocca-Volmerange, B. Lacy, M. Teplitz, H. Dey, A. Dickinson, A. van Brengel, W. Miley, G. Rottgering, H. Eisenhardt, P. McCarthy, P. De Breuck, F. Vernet, L. BE Chary, RR Teplitz, HI Sheth, K TI Spitzer observations of high redshift radio galaxies SO SECOND ANNUAL SPITZER SCIENCE CENTER CONFERENCE: INFRARED DIAGNOSTICS OF GALAXY EVOLUTION SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT 2nd Annual Spitzer Science Center Conference on Infrared Diagnostics of Galaxy Evolution CY NOV 14-16, 2005 CL Pasadena, CA ID ELLIPTIC GALAXIES; STAR-FORMATION; JETS AB We present the results of a comprehensive Spitzer survey of 70 radio galaxies across 1 < z < 5.2. Using IRAC, IRS and MIPS imaging we determine the rest-frame AGN contribution to the stellar emission peak at 1.6 mu m. The stellar luminosities are found to be consistent with that of a giant elliptical with a stellar mass of 10(11-12) M-circle dot. The mean stellar mass remains constant at 10(11-5) M-circle dot up to z = 3 indicating that the upper end of the mass function is already in place at redshift 3. The mid-IR luminosities imply bolometric IR luminosities that would classify most sources as ULIRGs. The mid-IR to radio luminosity generally correlate implying a common origin for these emissions. The ratio is higher than that found for lower redshift, i.e. z < 1, radio galaxies. C1 [Seymour, N.; Stern, D.; Lacy, M.; Teplitz, H.] CALTECH, Spitzer Sci Ctr, Mail Code 220-6,1200 E Calif Blvd, Pasadena, CA 91125 USA. [Stern, D.; Eisenhardt, P.] Jet Prop Lab, Pasadena, CA 91125 USA. [De Breuck, C.; Vernet, J.; Fosbury, R.; Rettura, A.; De Breuck, F.; Vernet, L.] ESO, Munich, Germany. [Rettura, A.; Rocca-Volmerange, B.] IAP, Delhi, India. [Zirm, A.] Space Telescope Sci Inst, Baltimore, MD 21218 USA. [Dey, A.; Dickinson, A.] Natl Opt Astron Observ, Tucson, AZ 85719 USA. [van Brengel, W.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. [Miley, G.; Rottgering, H.] Leiden Univ, NL-2300 RA Leiden, Netherlands. [McCarthy, P.] OCIW, Pittsburgh, PA 15213 USA. RP Seymour, N (reprint author), CALTECH, Spitzer Sci Ctr, Mail Code 220-6,1200 E Calif Blvd, Pasadena, CA 91125 USA. NR 17 TC 0 Z9 0 U1 0 U2 2 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-325-6 J9 ASTR SOC P PY 2008 VL 381 BP 398 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHO46 UT WOS:000254828200075 ER PT B AU Brookes, MH Keene, J Quillen, AC Charmandaris, V Lawrence, CR Stern, D Werner, M AF Brookes, M. H. Keene, J. Quillen, A. C. Charmandaris, V. Lawrence, C. R. Stern, D. Werner, M. BE Chary, RR Teplitz, HI Sheth, K TI Spitzer observations of Centaurus A SO SECOND ANNUAL SPITZER SCIENCE CENTER CONFERENCE: INFRARED DIAGNOSTICS OF GALAXY EVOLUTION SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT 2nd Annual Spitzer Science Center Conference on Infrared Diagnostics of Galaxy Evolution CY NOV 14-16, 2005 CL Pasadena, CA ID SPACE-TELESCOPE AB We describe infrared observations of the radio galaxy Centaurus A made using the Spitzer Space Telescope. Data from IRAC, MIPS have been used to model the structure of the warped dusty disk and to detect infrared synchrotron emission from the radio jet at the position of the Northern Inner Radio Lobe. We also discuss future work with IRS low resolution spectral mapping data which will be used to probe the physical characteristics of the warped disk. C1 [Brookes, M. H.; Keene, J.; Quillen, A. C.; Lawrence, C. R.; Stern, D.; Werner, M.] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. [Charmandaris, V.] Univ Crete, Dept Phys, Iraklion 71003, Greece. [Charmandaris, V.] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. RP Brookes, MH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. FU NASA through Jet Propulsion Laboratory [960785] FX Development of MIPS was funded by NASA through the Jet Propulsion Laboratory, subcontract 960785. NR 15 TC 1 Z9 1 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-325-6 J9 ASTR SOC P PY 2008 VL 381 BP 405 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHO46 UT WOS:000254828200076 ER PT B AU Gorjian, V Cleary, K Werner, MW Lawrence, CR AF Gorjian, V. Cleary, K. Werner, M. W. Lawrence, C. R. BE Chary, RR Teplitz, HI Sheth, K TI Low resolution IRS spectra of nearby Seyfert galaxies SO SECOND ANNUAL SPITZER SCIENCE CENTER CONFERENCE: INFRARED DIAGNOSTICS OF GALAXY EVOLUTION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Annual Spitzer Science Center Conference on Infrared Diagnostics of Galaxy Evolution CY NOV 14-16, 2005 CL Pasadena, CA ID SPITZER-SPACE-TELESCOPE; ACTIVE GALACTIC NUCLEI AB We have obtained low-resolution spectra of 42 nearby Seyfert Active Galactic Nuclei. The AGNs were chosen to have a broad range of X-ray determined Hydrogen column densities from Compton thin to Compton thick. The spectral energy distributions are broadly consistent with higher column densities showing greater short wavelength absorption than lower column densities. C1 [Gorjian, V.; Cleary, K.; Werner, M. W.; Lawrence, C. R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gorjian, V (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-325-6 J9 ASTR SOC P PY 2008 VL 381 BP 409 EP 412 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHO46 UT WOS:000254828200077 ER PT B AU Hickox, RC Jones, C Forman, WR Murray, SS Brodwin, M AF Hickox, R. C. Jones, C. Forman, W. R. Murray, S. S. Brodwin, M. CA Chandra XBootes Spitzer IRAC Shallow Survey AGES NOAO DWFS Teams BE Chary, RR Teplitz, HI Sheth, K TI X-ray and infrared properties of galaxies and AGNs in the 9 deg(2) Bootes field SO SECOND ANNUAL SPITZER SCIENCE CENTER CONFERENCE: INFRARED DIAGNOSTICS OF GALAXY EVOLUTION SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT 2nd Annual Spitzer Science Center Conference on Infrared Diagnostics of Galaxy Evolution CY NOV 14-16, 2005 CL Pasadena, CA AB We examine the X-ray and infrared properties of galaxies and AGNs in the 9 square degree Bootes field, using data from the Chandra XBootes and Spitzer IRAC Shallow Surveys, as well as optical spectroscopy from the AGES survey. A sample of similar to 30,000 objects are detected in all four TRAC bands, of which similar to 2,000 are associated with X-ray sources. We also study X-ray fainter sources using stacking techniques, and find that X-ray fluxes are highest for objects with IRAC colors that are known to be characteristic of AGNs. Because these are shallow, wide-field surveys, they probe the bright end of the AGN luminosity function out to spectroscopic redshifts as high as z = 3-4. We can use this multi-wavelength data set to explore the properties and redshift evolution of a large sample of luminous active galaxies. C1 [Hickox, R. C.; Jones, C.; Forman, W. R.; Murray, S. S.] Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. [Brodwin, M.] Jet Propuls Lab, Caltech, Pasadena, CA USA. RP Hickox, RC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-325-6 J9 ASTR SOC P PY 2008 VL 381 BP 418 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHO46 UT WOS:000254828200079 ER PT S AU Chattopadhyay, G AF Chattopadhyay, Goutam BE Mukhopadhyay, SC Huang, RYM TI Submillimeter-Wave Coherent and Incoherent Sensors for Space Applications SO SENSORS: ADVANCEMENTS IN MODELING, DESIGN ISSUES, FABRICATION AND PRACTICAL APPLICATIONS SE Lecture Notes in Electrical Engineering LA English DT Article; Book Chapter ID TERAHERTZ TECHNOLOGY; HETERODYNE INSTRUMENT; RADIO ASTRONOMY; HIGH-REDSHIFT; 1 THZ; MICROWAVE; SPECTROMETER; MILLIMETER; GALAXIES; ARRAY AB Most of the radiation in the Universe is emitted at wavelengths longer than 10 microns (30 THz), and this peaks at about 100 microns (3 THz), if we exclude contributions from the cosmic microwave background (CMB). Radiation in these wavelengths highlights warm phenomena, processes of change such as star formation, formation of planetary systems, and galaxy evolution; atmospheric constituents and dynamics of the planets and comets and tracers for global monitoring and the ultimate health of the earth. Sensors at far-infrared and submillimeter wavelengths provide unprecedented sensitivity for astrophysical, planetary, earth observing, and ground-based imaging instruments. Very often, for spaced based platforms where the instruments are not limited by atmospheric losses and absorption, the overall instrument sensitivity is dictated by the sensitivity of the sensors themselves. Moreover, some of the cryogenic sensors at submillimeter wavelengths provide almost quantum-limited sensitivity. Frequency sources at submillimeter wavelengths with adequate output power for transmitters and local oscillators are not easily available, and pose the greatest challenge for advancement of this field. This article provides an overview of the state-of-the-art of submillimeter-wave sensors for a variety of space-borne applications and their performance and capabilities. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Chattopadhyay, G (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. EM goutam@jpl.nasa.gov NR 86 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 1876-1100 BN 978-3-540-69033-7 J9 LECT NOTES ELECTR EN PY 2008 VL 21 BP 387 EP 414 D2 10.1007/978-3-540-69033-7 PG 28 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Robotics SC Automation & Control Systems; Computer Science; Engineering; Robotics GA BNM01 UT WOS:000274923000019 ER PT S AU Sherrit, S Bao, X Bar-Cohen, Y AF Sherrit, S. Bao, X. Bar-Cohen, Y. BE Tomizuka, M TI Solid micro horn array (SMIHA) for acoustic matching SO SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2008, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems CY MAR 10-13, 2008 CL San Diego, CA SP SPIE, Amer Soc Mech Engineers, Intelligent Mat Forum Jet Propulsion Lab, Natl Sci Fdn DE piezoelectric devices; acoustic wave; acoustic matching; backing layers; impedance; power transmission ID TRANSDUCERS AB Transduction of electrical signals to mechanical signals and vice-versa in piezoelectric materials is controlled by the material coupling coefficient. In general in a loss-less material the ratio of energy conversion per cycle is proportional to the square of the coupling coefficient. In practical transduction however the impedance mismatch between the piezoelectric material and the electrical drive circuitry or the mechanical structure can have a significant impact on the power transfer. In this paper a novel method of matching the acoustic impedance of structures to the piezoelectric material are described and discussed in relation to the objective of increasing power transmission and efficiency. In typical methods the density and acoustic velocity of the matching layer is adjusted to give "ideal" matching between the transducer and the load. The approach discussed in this paperutilizes solid micro horn arrays in the matching layer which channel the stress and increase the strain in the layer. This approach is found to have potential applications in energy harvesting, medical ultrasound and in liquid and gas coupled transducers. C1 [Sherrit, S.; Bao, X.; Bar-Cohen, Y.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sherrit, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 1 Z9 1 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7118-5 J9 PROC SPIE PY 2008 VL 6932 AR 69322X DI 10.1117/12.776384 PN 1,2 PG 9 WC Engineering, Aerospace; Engineering, Civil; Engineering, Mechanical; Remote Sensing; Ophthalmology SC Engineering; Remote Sensing; Ophthalmology GA BHW56 UT WOS:000257062100086 ER PT S AU Chouinard, C Knight, R Jones, G Tran, D AF Chouinard, Caroline Knight, Russell Jones, Grailing Tran, Daniel BE Howard, RT Motaghedi, P TI Orbital Express mission operations planning and resource management using ASPEN SO SENSORS AND SYSTEMS FOR SPACE APPLICATIONS II SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Sensors and Systems for Space Applications II CY MAR 17-18, 2008 CL Orlando, FL SP SPIE DE Orbital Express; ASPEN; Automated Planning and Scheduling AB As satellite equipment and mission operations become more costly, the drive to keep working equipment running with less labor-power rises. Demonstrating the feasibility of autonomous satellite servicing was the main goal behind the Orbital Express (OE) mission. Like a tow-truck delivering gas to a car on the road, the "servicing" satellite of OE had to find the "client" from several kilometers away, connect directly to the client, and transfer fluid (or a battery) autonomously, while on earth-orbit [1]. The mission met 100% of its success criteria, and proved that autonomous satellite servicing is now a reality for space operations. Planning the satellite mission operations for OE required the ability to create a plan which could be executed autonomously over variable conditions. As the constraints for execution could change weekly, daily, and even hourly, the tools used create the mission execution plans needed to be flexible and adaptable to many different kinds of changes. At the same time, the hard constraints of the plans needed to be maintained and satisfied. The Automated Scheduling and Planning Environment (ASPEN) tool, developed at the Jet Propulsion Laboratory [2], was used to create the schedule of events in each daily plan for the two satellites of the OE mission. This paper presents an introduction to the ASPEN tool, an overview of the constraints of the OE domain, the variable conditions that were presented within the mission, and the solution to operations that ASPEN provided. ASPEN has been used in several other domains, including research rovers, Deep Space Network scheduling research, and in flight operations for the NASA's Earth Observing One mission's EO I satellite. Related work is discussed, as are the future of ASPEN and the future of autonomous satellite servicing. C1 [Chouinard, Caroline; Knight, Russell; Jones, Grailing; Tran, Daniel] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chouinard, C (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM caroline.m.chouinard@jpl.nasa.gov NR 13 TC 0 Z9 0 U1 1 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7149-9 J9 PROC SPIE PY 2008 VL 6958 AR 695806 DI 10.1117/12.782454 PG 8 WC Engineering, Aerospace; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BHY74 UT WOS:000257485600003 ER PT B AU Bareiss, R Griss, M AF Bareiss, Ray Griss, Martin GP ACM TI A Story-Centered, Learn-by-Doing Approach to Software Engineering Education SO SIGCSE'08: PROCEEDINGS OF THE 39TH ACM TECHNICAL SYMPOSIUM ON COMPUTER SCIENCE EDUCATION LA English DT Proceedings Paper CT 39th ACM Technical Symposium on Computer Science Education CY MAR 12-15, 2008 CL Portland, OR SP ACM SIGCSE, ACM SIGACCESS DE Software Engineering Education; Active Learning; Learning by Doing; Story-Centered Curricula AB Carnegie Mellon's West Coast Campus offers an MS in Software Engineering, with technical and development management tracks, targeted at working software professionals in Silicon Valley. We believe the program to be unique in that it is entirely team-based and project-centered. Students learn by doing as they are coached just in time by faculty in the context of authentic projects, and they are evaluated based on what they produce. Student satisfaction is high: 92% believe that the program has given them a competitive advantage with respect to their professional peers, and their promotion and salary histories bear out this belief. C1 [Bareiss, Ray; Griss, Martin] NASA Ames Res Pk, Moffett Field, CA 94035 USA. EM ray.bareiss@west.cmu.edu; martin.griss@west.cmu.edu OI Griss, Martin/0000-0002-8148-6967 NR 9 TC 0 Z9 0 U1 0 U2 2 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036-9998 USA BN 978-1-59593-947-0 PY 2008 BP 221 EP 225 PG 5 WC Computer Science, Interdisciplinary Applications; Education & Educational Research; Education, Scientific Disciplines; Social Sciences, Interdisciplinary SC Computer Science; Education & Educational Research; Social Sciences - Other Topics GA BJH00 UT WOS:000265741800054 ER PT S AU Neudeck, PG Spry, DJ Chen, LY Chang, CW Beheim, GM Okojie, RS Evans, LJ Meredith, RD Ferrier, TL Krasowski, MJ Prokop, NF AF Neudeck, Philip G. Spry, David J. Chen, Liang-Yu Chang, Carl W. Beheim, Glenn M. Okojie, Robert S. Evans, Laura J. Meredith, Roger D. Ferrier, Terry L. Krasowski, Michael J. Prokop, Norman F. BE Dudley, M Johnson, CM Powell, AR Ryu, SH TI Long-term characterization of 6H-SiC transistor integrated circuit technology operating at 500 degrees C SO SILICON CARBIDE 2008 - MATERIALS, PROCESSING AND DEVICES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Conference on Silicon Carbide - Materials, Processing and Devices held at the 2008 MRS Spring Meeting CY MAR 25-27, 2008 CL San Francisco, CA ID DEFECTS AB NASA has been developing very high temperature semiconductor integrated circuits for use in the hot sections of aircraft engines and for Venus exploration. This paper reports on long-term 500 degrees C electrical operation of prototype 6H-SiC integrated circuits based on epitaxial 6H-SiC junction field effect transistors (JFETs). As of this writing, some devices have surpassed 4000 hours of continuous 500 degrees C electrical operation in oxidizing air atmosphere with minimal change in relevant electrical parameters. C1 [Neudeck, Philip G.; Beheim, Glenn M.; Okojie, Robert S.; Evans, Laura J.; Meredith, Roger D.; Ferrier, Terry L.; Krasowski, Michael J.; Prokop, Norman F.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Neudeck, PG (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 77-1, Cleveland, OH 44135 USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 978-1-60511-039-4 J9 MATER RES SOC SYMP P PY 2008 VL 1069 BP 209 EP 214 PG 6 WC Materials Science, Multidisciplinary; Physics, Multidisciplinary SC Materials Science; Physics GA BIE44 UT WOS:000258909700027 ER PT S AU Nayar, H Balaram, BJ Cameron, J Jain, A Lim, C Mukherjee, R Peters, S Pomerantz, M Reder, L Shakkottai, P Wall, S AF Nayar, Hari Balaram, Bob J. Cameron, Jonathan Jain, Abhinandan Lim, Christopher Mukherjee, Rudranarayan Peters, Stephen Pomerantz, Marc Reder, Leonard Shakkottai, Partha Wall, Stephen BE Carpin, S Noda, I Pagello, E Reggiani, M VonStryk, O TI A Lunar Surface Operations Simulator SO SIMULATION, MODELING, AND PROGRAMMING FOR AUTONOMOUS ROBOTS, PROCEEDINGS SE Lecture Notes in Artificial Intelligence LA English DT Proceedings Paper CT 1st International Conference on Simulation, Modeling, and Programming for Autonomous Robots CY NOV 03-06, 2008 CL Venice, ITALY SP Telecon Italia, Univ Padua, Dept Informat Engn, Ist Ingegner Biomed CNR, Univ Padua AB The Lunar Surface Operations Simulator (LSOS) is being developed to support planning and design of space missions to return astronauts to the moon. Vehicles, habitats, dynamic and physical processes and related environment systems are modeled and simulated in LSOS to assist in the visualization and design optimization of systems for lunar surface operations. A parametric analysis tool and a data browser were also implemented to provide an intuitive interface to run multiple simulations and review their results. The simulator and parametric analysis capability are described in this paper. C1 [Nayar, Hari; Balaram, Bob J.; Cameron, Jonathan; Jain, Abhinandan; Lim, Christopher; Mukherjee, Rudranarayan; Peters, Stephen; Pomerantz, Marc; Reder, Leonard; Shakkottai, Partha; Wall, Stephen] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nayar, H (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 978-3-540-89075-1 J9 LECT NOTES ARTIF INT PY 2008 VL 5325 BP 65 EP 74 PG 10 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA BIP89 UT WOS:000261730000010 ER PT B AU Neeck, SP Hammer, TF AF Neeck, Steven P. Hammer, Theodore F. BE Sandau, R Roser, HP Valenzuela, A TI NASA Earth observation programs and small satellites SO SMALL SATELLITES FOR EARTH OBSERVATION: SELECTED CONTRIBUTIONS LA English DT Proceedings Paper CT 6th IAA International Symposium on Small Satellites for Earth Observation CY APR 23-26, 2007 CL German Aerosp Ctr, Berlin, GERMANY HO German Aerosp Ctr AB NASA's strategic goal in Earth science is motivated by the fundamental question: "How is the Earth changing and what are the consequences for life on Earth?" NASA's mission in Earth science as mandated by the U.S. Space Act is to "... conduct aeronautical and space activities so as to contribute materially to ... the expansion of human knowledge of the Earth and of phenomena in the atmosphere and space". Therefore, NASA's role is unique and highly complements those of other U.S. Federal agencies by continually advancing Earth system science from space, creating new remote sensing capabilities, and enhancing the operational capabilities of other agencies and collaborating with them to advance Earth science goals. NASA's Earth Science Division (ESD) currently has a system of spacecraft collecting observations of the Earth system and in the months and years ahead will deploy new satellites and constellations with advanced measurement capabilities. Small satellites (similar to 500kg or less) have been crucial contributors to achieving NASA's Earth science measurements and will continue to be so in the future. The U.S. National Research Council (NRC) is just now completing its first decadal survey for Earth science and applications from space. This survey will be used to set priorities for future missions to 2017 and beyond. Current status of ESD flight programs, preparations for the NRC decadal survey, and the role of small satellites will be discussed. C1 [Neeck, Steven P.; Hammer, Theodore F.] NASA, Sci Mission Directorate, Washington, DC 20546 USA. RP Neeck, SP (reprint author), NASA, Sci Mission Directorate, Washington, DC 20546 USA. NR 2 TC 0 Z9 0 U1 1 U2 2 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 978-1-4020-6942-0 PY 2008 BP 3 EP 12 DI 10.1007/978-1-4020-6943-7_1 PG 10 WC Remote Sensing SC Remote Sensing GA BHW27 UT WOS:000256999100001 ER PT B AU Fredrickson, S AF Fredrickson, Steven BE Helvajian, H Janson, SW TI Mini AERCam: The Miniature Autonomous Extravehicular Robotic Camera SO SMALL SATELLITES: PAST, PRESENT , AND FUTURE LA English DT Article; Book Chapter C1 NASA, Lyndon B Johnson Space Ctr, Intelligent Syst Branch, Automat Robot & Simulat Div, Houston, TX 77058 USA. RP Fredrickson, S (reprint author), NASA, Lyndon B Johnson Space Ctr, Intelligent Syst Branch, Automat Robot & Simulat Div, Houston, TX 77058 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUTICS & ASTRONAUTICS PI RESTON PA 1801 ALEXANDER BELL DR, STE 500, RESTON, VA 20191-4344 USA BN 978-1-884989-22-3 PY 2008 BP 487 EP 523 PG 37 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BKT30 UT WOS:000269159700016 ER PT S AU Sokolowski, W Tan, S Willis, P Pryor, M AF Sokolowski, Witold Tan, Seng Willis, Paul Pryor, Mark BE Voelcker, NH Thissen, HW TI Shape memory self-deployable structures for solar sails SO SMART MATERIALS V SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Smart Materials V CY DEC 10-12, 2008 CL Melbourne, AUSTRALIA SP SPIE, RMIT Univ DE expandable structures; shape memory polymers; open cellular structures; glass transition temperature Tg ID ANTENNA AB A cold-hibernated elastic memory (CHEM) structures technology is one of the most recent results of the quest for simple, reliable and low-cost self-deployable structures. The CHEM technology utilizes shape-memory polymers in open-cell foam structures or sandwich structures made of shape-memory-polymer foam cores and polymeric laminated-composite skins. It takes advantage of a polymer's shape memory and the corresponding internal elastic recovery forces to self-deploy a compacted structure. This paper describes these structures and their major advantages over other expandable and deployable structures presently used. Previous preliminary investigations and experiments have confirmed the feasibility of certain CHEM structures for space applications. Further improvements in CHEM technology and structure design widen potential space applications, including advanced solar sail structural concepts that are revealed and described in this paper. C1 [Sokolowski, Witold; Willis, Paul] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sokolowski, W (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Voelcker, Nicolas/D-6199-2012 OI Voelcker, Nicolas/0000-0002-1536-7804 NR 30 TC 5 Z9 5 U1 4 U2 13 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7519-0 J9 PROC SPIE PY 2008 VL 7267 AR 72670K DI 10.1117/12.814301 PG 14 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Optics SC Science & Technology - Other Topics; Materials Science; Optics GA BCB33 UT WOS:000309594100010 ER PT S AU Wu, MC Pater, RH DeHaven, SL AF Wu, Meng-Chou Pater, Ruth H. DeHaven, Stanton L. BE Ecke, W Peters, KJ Meyendorf, NG TI Effects of coating and diametric load on fiber Bragg gratings as cryogenic temperature sensors - art. no. 693303 SO SMART SENSOR PHENOMENA, TECHNOLOGY, NETWORKS, AND SYSTEMS 2008 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Sensor, Phenomena, Technology, Networks, and Systems CY MAR 10-12, 2008 CL San Diego, CA SP SPIE, Amer Soc Mech Engineers, Intelligent Mat Forum, Jet Propuls Lab, Natl Sci Fdn DE fiber Bragg gratings; temperature sensors; cryogenic temperatures; pressurized fiber Bragg gratings ID OPTICAL-FIBER; STRAIN; FABRICATION AB Cryogenic temperature sensing was demonstrated using pressurized fiber Bragg gratings (PFBGs) with polymer coating of various thicknesses. The PFBG was obtained by applying a small diametric load to a regular fiber Bragg grating (FBG). The Bragg wavelengths of FBGs and PFBG were measured at temperatures from 295 K to 4.2 K. The temperature sensitivities of the FBGs were increased by the polymer coating. A physical model was developed to relate the Bragg wavelength shifts to the thermal expansion coefficients, Young's moduli, and thicknesses of the coating polymers. When a diametric load of no more than 15 N was applied to a FBG, a pressure-induced transition occurred at 200 K during the cooling cycle. The pressure induced transition yielded PFBG temperature sensitivities three times greater than conventional FBGs for temperatures ranging from 80 to 200 K, and ten times greater than conventional fibers for temperatures below 80 K. PFBGs were found to produce an increased Bragg wavelength shift of 2.2 nm compared to conventional FBGs over the temperature range of 4.2 to 300 K. This effect was independent of coating thickness and attributed to the change of the fiber thermo-optic coefficient. C1 [Wu, Meng-Chou; Pater, Ruth H.; DeHaven, Stanton L.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Wu, MC (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 14 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7119-2 J9 P SOC PHOTO-OPT INS PY 2008 VL 6933 BP 93303 EP 93303 DI 10.1117/12.775895 PG 10 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Mechanical; Remote Sensing; Optics SC Computer Science; Engineering; Remote Sensing; Optics GA BHW84 UT WOS:000257108400002 ER PT S AU Banks, CE Grant, J Russell, S Arnett, S AF Banks, Curtis E. Grant, Joseph Russell, Sam Arnett, Shawn BE Ecke, W Peters, KJ Meyendorf, NG TI Strain measurement during stress rupture of composite over-wrapped pressure vessel with fiber Bragg gratings sensors SO SMART SENSOR PHENOMENA, TECHNOLOGY, NETWORKS, AND SYSTEMS 2008 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Smart Sensor, Phenomena, Technology, Networks, and Systems CY MAR 10-12, 2008 CL San Diego, CA SP SPIE, Amer Soc Mech Engineers, Intelligent Mat Forum, Jet Propuls Lab, Natl Sci Fdn AB Fiber optic Bragg gratings were used to measure strain fields during Stress Rupture (SSM) test of Kevlar Composite Over-Wrapped Pressure Vessels (COPVs). The sensors were embedded under the over-wrapped attached to the liner released from the Kevlar and attached to the Kevlar released from the liner. Additional sensors (foil gages and fiber bragg gratings) were surface mounted on the COPV liner. C1 [Banks, Curtis E.] NASA, George C Marshall Space Flight Ctr, Integrated Struct Hlth Monitoring & Sensors Branc, Huntsville, AL 35812 USA. RP Banks, CE (reprint author), NASA, George C Marshall Space Flight Ctr, Integrated Struct Hlth Monitoring & Sensors Branc, EV43, Huntsville, AL 35812 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7119-2 J9 PROC SPIE PY 2008 VL 6933 AR 69330O DI 10.1117/12.776419 PG 10 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Mechanical; Remote Sensing; Optics SC Computer Science; Engineering; Remote Sensing; Optics GA BHW84 UT WOS:000257108400019 ER PT S AU Banks, CE Grant, J Russell, S Arnett, S AF Banks, Curtis E. Grant, Joseph Russell, Sam Arnett, Shawn BE Ecke, W Peters, KJ Meyendorf, NG TI Local strain measurement of Kevlar strand with fiber optic Bragg grating SO SMART SENSOR PHENOMENA, TECHNOLOGY, NETWORKS, AND SYSTEMS 2008 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Smart Sensor, Phenomena, Technology, Networks, and Systems CY MAR 10-12, 2008 CL San Diego, CA SP SPIE, Amer Soc Mech Engineers, Intelligent Mat Forum, Jet Propuls Lab, Natl Sci Fdn AB 1987 DuPont manufactured 4560 denier Kevlar/Epoxy strands were instrumented with nine and three sensors each. Stress tests were performed at 30,45,60,70 and 80% of ultimate strength with dwell times of 10,000 seconds. FBG showed uneven stress levels which is contrary to conventional observation. C1 [Banks, Curtis E.] NASA, George C Marshall Space Flight Ctr, Integrated Struct Hlth Monitoring & Sensors Branc, Huntsville, AL 35812 USA. RP Banks, CE (reprint author), NASA, George C Marshall Space Flight Ctr, Integrated Struct Hlth Monitoring & Sensors Branc, EV43, Huntsville, AL 35812 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7119-2 J9 PROC SPIE PY 2008 VL 6933 AR 693307 DI 10.1117/12.776626 PG 7 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Mechanical; Remote Sensing; Optics SC Computer Science; Engineering; Remote Sensing; Optics GA BHW84 UT WOS:000257108400004 ER PT B AU Bigelow, G Noebe, R Padula, S Garg, A Olson, D AF Bigelow, Glen Noebe, Ronald Padula, Santo, II Garg, Anita Olson, David BE Berg, B Mitchell, MR Proft, J TI DEVELOPMENT AND CHARACTERIZATION OF IMPROVED NiTiPd HIGH-TEMPERATURE SHAPE-MEMORY ALLOYS BY SOLID-SOLUTION STRENGTHENING AND THERMOMECHANICAL PROCESSING SO SMST 2006: PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON SHAPE MEMORY AND SUPERELASTIC TECHNOLOGIES LA English DT Proceedings Paper CT International Conference on Shape Memory and Superelastic Technologies CY MAY 07-11, 2006 CL Pacific Grove, CA SP Admedes Schussler GmbH, Boston Sci, Dearborn Precis Tubular Prod, Edwards Lifesciences, Ft Wayne Met Res Prod Corp, Guidant Endovasc Solut, Johnson Matthey, Kemac Technologies, Mech & Mat Consulting, Medtron Vasc, MeKo Laser Mat Proc, Memry Corp, Minitubes, Nitinol Devices & components, SAES Getters Grp, Special Met Corp, Shape Mem Alloys Div, Ulbrich Stainless Steels & Special Met AB The need for compact, solid-state actuation systems for use in the aerospace, automotive, and other transportation industries is currently motivating research in high-temperature shape-memory alloys (HTSMA) with transformation temperatures greater than 100 degrees C. One of the basic high-temperature alloys investigated to fill this need is Ni(19.5)Ti(50.5)Pd(30). Initial testing has indicated that this alloy, while having acceptable work characteristics, suffers from significant permanent deformation (or ratcheting) during thermal cycling under load. In an effort to overcome this deficiency, various solid-solution alloying and thermomechanical processing schemes were investigated. Solid-solution strengthening was achieved by substituting 5at% gold or platinum for palladium in Ni(19.5)Ti(50.5)Pd(30), the so-called baseline alloy, to strengthen the martensite and austenite phases against slip processes and improve thermomechanical behavior. Tensile properties, work behavior, and dimensional stability during repeated thermal cycling under load for the ternary and quaternary alloys were compared. The relative difference in yield strength between the martensite and austenite phases and the dimensional stability of the alloy were improved by the quaternary additions, while work output was only minimally impacted. The three alloys were also thermomechanically processed by cycling repeatedly through the transformation range under a constant stress. This so-called "training" process dramatically improved the dimensional stability in these samples and also recovered the slight decrease in work output caused by quaternary alloying. An added benefit of the solid-solution strengthening was maintenance of enhanced dimensional stability of the trained material to higher temperatures compared to the baseline alloy, providing a greater measure of over-temperature capability. C1 [Bigelow, Glen; Noebe, Ronald; Padula, Santo, II; Garg, Anita] NASA Glenn Res Ctr, Cleveland, OH USA. RP Bigelow, G (reprint author), NASA Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH USA. NR 23 TC 5 Z9 5 U1 1 U2 2 PU ASM INTERNATIONAL PI MATERIALS PARK PA 9503 KINSMAN RD, MATERIALS PARK, OH 44073 USA BN 978-0-87170-862-5 PY 2008 BP 113 EP 131 DI 10.1361/cp2006smst113 PG 19 WC Materials Science, Multidisciplinary SC Materials Science GA BQI76 UT WOS:000281128400012 ER PT B AU Noebe, R Draper, S Gaydosh, D Garg, A Lerch, B Penney, N Bigelow, G Padula, S Brown, J AF Noebe, Ronald Draper, Susan Gaydosh, Darrell Garg, Anita Lerch, Brad Penney, Nicholas Bigelow, Glen Padula, Santo, II Brown, Jeff BE Berg, B Mitchell, MR Proft, J TI Effect of Thermomechanical Processing on the Microstructure, Properties, and Work Behavior of a Ti(50.5)Ni(29.5)Pt(20) High-Temperature Shape Memory Alloy SO SMST 2006: PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON SHAPE MEMORY AND SUPERELASTIC TECHNOLOGIES LA English DT Proceedings Paper CT International Conference on Shape Memory and Superelastic Technologies CY MAY 07-11, 2006 CL Pacific Grove, CA SP Admedes Schussler GmbH, Boston Sci, Dearborn Precis Tubular Prod, Edwards Lifesciences, Ft Wayne Met Res Prod Corp, Guidant Endovasc Solut, Johnson Matthey, Kemac Technologies, Mech & Mat Consulting, Medtron Vasc, MeKo Laser Mat Proc, Memry Corp, Minitubes, Nitinol Devices & components, SAES Getters Grp, Special Met Corp, Shape Mem Alloys Div, Ulbrich Stainless Steels & Special Met AB TiNiPt shape memory alloys are particularly promising for use as solid state actuators in environments up to 300 degrees C, due to a reasonable balance of properties, including acceptable work output. However, one of the challenges to commercializing a viable high-temperature shape memory alloy (HTSMA) is to establish the appropriate primary and secondary processing techniques for fabrication of the material in a required product form such as rod and wire. Consequently, a Ti(50.5)Ni(29.5)Pt(20) alloy was processed using several techniques including single-pass high-temperature extrusion, multiple-pass high-temperature extrusion, and cold drawing to produce bar stock, thin rod, and fine wire, respectively. The effects of heat treatment on the hardness, grain size, room temperature tensile properties, and transformation temperatures of hot- and cold-worked material were examined. Basic tensile properties as a function of temperature and the strain-temperature response of the alloy under constant load, for the determination of work output, were also investigated for various forms of the Ti(50.5)Ni(29.5)Pt(20) alloy, including fine wire. C1 [Noebe, Ronald; Draper, Susan; Gaydosh, Darrell; Garg, Anita; Lerch, Brad; Penney, Nicholas; Bigelow, Glen; Padula, Santo, II] NASA Glenn Res Ctr, Cleveland, OH USA. RP Noebe, R (reprint author), NASA Glenn Res Ctr, Cleveland, OH USA. NR 17 TC 10 Z9 10 U1 1 U2 5 PU ASM INTERNATIONAL PI MATERIALS PARK PA 9503 KINSMAN RD, MATERIALS PARK, OH 44073 USA BN 978-0-87170-862-5 PY 2008 BP 409 EP 426 DI 10.1361/cp2006smst409 PG 18 WC Materials Science, Multidisciplinary SC Materials Science GA BQI76 UT WOS:000281128400040 ER PT B AU Padula, S Bigelow, G Noebe, R Gaydosh, D Garg, A AF Padula, Santo, II Bigelow, Glen Noebe, Ronald Gaydosh, Darrell Garg, Anita BE Berg, B Mitchell, MR Proft, J TI CHALLENGES AND PROGRESS IN THE DEVELOPMENT OF HIGH-TEMPERATURE SHAPE MEMORY ALLOYS BASED ON NITIX COMPOSITIONS FOR HIGH-FORCE ACTUATOR APPLICATIONS SO SMST 2006: PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON SHAPE MEMORY AND SUPERELASTIC TECHNOLOGIES LA English DT Proceedings Paper CT International Conference on Shape Memory and Superelastic Technologies CY MAY 07-11, 2006 CL Pacific Grove, CA SP Admedes Schussler GmbH, Boston Sci, Dearborn Precis Tubular Prod, Edwards Lifesciences, Ft Wayne Met Res Prod Corp, Guidant Endovasc Solut, Johnson Matthey, Kemac Technologies, Mech & Mat Consulting, Medtron Vasc, MeKo Laser Mat Proc, Memry Corp, Minitubes, Nitinol Devices & components, SAES Getters Grp, Special Met Corp, Shape Mem Alloys Div, Ulbrich Stainless Steels & Special Met ID MARTENSITIC TRANSFORMATIONS; MICROSTRUCTURE; IMPROVEMENT AB Interest in high-temperature shape memory alloys (HTSMA) has been growing in the aerospace, automotive, process control, and energy industries. However, actual materials development has seriously lagged component design, with current commercial NiTi alloys severely limited in their temperature capability. Additions of Pd, Pt, Au, Hf, and Zr at levels greater than 10 at.% have been shown to increase the transformation temperature of NiTi alloys, but with few exceptions, the shape memory behavior (strain recovery) of these NiTiX systems has been determined only under stress free conditions. Given the limited amount of basic mechanical test data and general lack of information regarding the work attributes of these materials, a program to investigate the mechanical behavior of potential HTSMAs, with transformation temperatures between 100 and 500 degrees C, was initiated. This paper summarizes the results of studies, focusing on both the practical temperature limitations for ternary TiNiPd and TiNiPt systems based on the work output of these alloys and the ability of these alloys to undergo repeated thermal cycling under load without significant permanent deflection or "walking". These issues are ultimately controlled by the detwinning stress of the martensite and resistance to dislocation slip of the individual martensite and austenite phases. Finally, general rules will be provided that govern the development of useful, high work output, next-generation HTSMA materials, based on the lessons learned in this work. C1 [Padula, Santo, II; Bigelow, Glen; Noebe, Ronald; Gaydosh, Darrell; Garg, Anita] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Padula, S (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 20 TC 5 Z9 5 U1 0 U2 6 PU ASM INTERNATIONAL PI MATERIALS PARK PA 9503 KINSMAN RD, MATERIALS PARK, OH 44073 USA BN 978-0-87170-862-5 PY 2008 BP 787 EP 801 DI 10.1361/cp2006smst787 PG 15 WC Materials Science, Multidisciplinary SC Materials Science GA BQI76 UT WOS:000281128400072 ER PT B AU Bigelow, GS Gaydosh, DJ Garg, A Padula, SA Noebe, RD AF Bigelow, Glen S. Gaydosh, Darrell J. Garg, Anita Padula, Santo A., II Noebe, Ronald D. BE Miyazaki, S TI EFFECTS OF STOICHIOMETRY ON TRANSFORMATION TEMPERATURES AND ACTUATOR-TYPE PERFORMANCE OF NITIPD AND NITIPDX HIGH-TEMPERATURE SHAPE MEMORY ALLOYS SO SMST-2007: PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON SHAPE MEMORY AND SUPERELASTIC TECHNOLOGIES LA English DT Proceedings Paper CT International Conference on Shape Memory and Superelastic Technologies CY DEC 02-05, 2007 CL Tsukuba, JAPAN ID NI ALLOYS AB Ternary NiTiPd and quaternary NiTiPdX (X=Au, Pt, Hf) high-temperature shape memory alloys (HTSMAs) were produced with titanium-equivalent (Ti+Hf) compositions from 50.5 to 49.0 at.%. Thermomechanical testing in compression was used to evaluate the transformation temperatures, transformation strain, work output, and permanent deformation behavior of each alloy to study the effects of quaternary alloying and stoichiometry on HTSMA behavior. Microstructural evaluation showed the presence of second phases for all alloy compositions. No-load transformation temperatures in the stoichiometric alloys were relatively unchanged by Au substitution, slightly increased by substitution with Pt, and severely depressed by substitution of Hf for Ti. Transformation temperatures were highest in the Ti-rich and stoichiometric compositions, and lower in the compositions with less than 50 at.% Ti (+Hf). During constant-load thermal cycling, transformation strain, and therefore work output, increased with increasing stress. Transformation strain was relatively unchanged by composition in the NiTiPdHf and NiTiPdPt alloys, while it decreased with decreasing Ti content in NiTiPd and increased with decreasing Ti content in the NiTiPdAu alloys. Permanent strain associated with the constant-load thermal cycling was lowest for alloys with Ti-equivalent-lean compositions. Based on these results, basic rules for optimizing the composition of NiTiPd alloys for actuator performance are discussed. C1 [Bigelow, Glen S.; Gaydosh, Darrell J.; Garg, Anita; Padula, Santo A., II; Noebe, Ronald D.] NASA, Glenn Res Ctr, Cleveland, OH USA. RP Bigelow, GS (reprint author), NASA, Glenn Res Ctr, Cleveland, OH USA. NR 11 TC 2 Z9 2 U1 1 U2 6 PU ASM INTERNATIONAL PI MATERIALS PARK PA 9503 KINSMAN RD, MATERIALS PARK, OH 44073 USA BN 978-0-87170-722-2 PY 2008 BP 83 EP 92 DI 10.1361/cp2007smst083 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA BQJ61 UT WOS:000281177500012 ER PT J AU Chen, F Kissel, DE West, LT Adkins, W Rickman, D Luvall, JC AF Chen, Feng Kissel, David E. West, Larry T. Adkins, W. Rickman, Doug Luvall, J. C. TI Mapping soil organic carbon concentration for multiple fields with image similarity analysis SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID REFLECTANCE SPECTROSCOPY; SHAPE SIMILARITY; CROP FIELDS; RETRIEVAL; TEXTURE; MATTER; DISTANCE; STORAGE; VIDEO; LINE AB Remotely sensed imagery with high spatial resolution has been used to map sod organic carbon (SOC) concentrations at a field scale with greatly increased accuracy and reduced cost compared with grid sampling. The procedure, however, requires each crop field to be sampled and mapped separately. The purpose of this study was to determine if cost could be reduced further by grouping a number of crop fields based on their image similarity, and then mapping them together as one group. Ten crop fields with a bare sod surface were selected from a 2000 NASA ATLAS image. The similarity among these fields was examined with the Ward neural network system (WNNS) using the image histogram features extracted from the image for each field. Seven fields were placed into two groups based on the coefficient of determination (R-2) values computed from WNNS, with one group consisting of three fields and the second consisting of four fields. Soil samples were taken from the seven fields along with their global positioning system locations and were divided into two data sets, with one for model development and the other for result checking. Models for mapping SOC concentrations were developed for each group of fields using a single procedure. The resulting maps were checked based on sod sample sets that were not used in model development and showed good agreement between mapped values and lab-determined values, with r(2) values of 0.80 for one group of fields and 0.77 for the second group of fields. The models were greatly improved compared with the model developed for all seven fields (R-2 was 0.87 and 0.91 for two groups vs. 0.63 for all fields and RMSE was 0.108 and 0.143 vs. 0.219 of SOC percentage). The model developed with similarity grouping was also compared with the model for field-by-field mapping and showed close agreement (R-2 was 0.87 for Group 1 vs. 0.89 for Field 2 only in Group 1 and RMSE was 0.108 vs. 0.119 for the same field). C1 [Chen, Feng; Kissel, David E.; West, Larry T.; Adkins, W.] Univ Georgia, Dept Crop & Soil Sci, Athens, GA 30602 USA. [Rickman, Doug; Luvall, J. C.] NASA, Global Hydrol & Climate Ctr, Huntsville, AL 35806 USA. RP Chen, F (reprint author), Univ Georgia, Dept Crop & Soil Sci, Athens, GA 30602 USA. EM fchen@uga.edu OI Rickman, Doug/0000-0003-3409-2882 NR 52 TC 14 Z9 15 U1 0 U2 6 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD JAN-FEB PY 2008 VL 72 IS 1 BP 186 EP 193 DI 10.2136/sssaj2007.0028 PG 8 WC Soil Science SC Agriculture GA 255TV UT WOS:000252681300023 ER PT J AU Hayashida, S Urita, N Noguchi, K Liu, X Chance, K AF Hayashida, S. Urita, N. Noguchi, K. Liu, X. Chance, K. TI Spatiotemporal Variation in Tropospheric Column Ozone over East Asia Observed by GOME and Ozonesondes SO SOLA LA English DT Article AB We analyzed tropospheric column ozone (TCO) observed by the GOME-1 (Global Ozone Monitoring Experiment; European Space Agency, 1995) and ozonesondes to determine the spatiotemporal variation in TCO over East Asia from 1996 to 2003. An enhanced TCO belt (E-TCO belt) was observed at approximately 35 degrees N throughout the year. The E-TCO belt moved northward from winter to summer and southward from summer to winter, strongly suggesting connection with the seasonal variation of meteorological conditions. The large enhancement of TCO found over central China in summer suggests that there is significant outflow of ozone from that region. This study presents the first satellite-derived comprehensive picture of the TCO spatiotemporal variation over East Asia, which has not been obtained from limited ground-based measurements. C1 [Hayashida, S.] Nara Womens Univ, Dept Informat & Comp Sci, Fac Sci, Nara 6308263, Japan. [Liu, X.; Chance, K.] Harvard Smithsonian Ctr Astrophys, Atom & Mol Phys Div, Cambridge, MA 02138 USA. [Liu, X.] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. RP Hayashida, S (reprint author), Nara Womens Univ, Dept Informat & Comp Sci, Fac Sci, Kitauoyanishi Machi, Nara 6308263, Japan. EM sachiko@ics.nara-wu.ac.jp RI Liu, Xiong/P-7186-2014 OI Liu, Xiong/0000-0003-2939-574X NR 16 TC 5 Z9 5 U1 0 U2 3 PU METEOROLOGICAL SOC JAPAN PI TOKYO PA C/O JAPAN METEOROLOGICAL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, 100-0004, JAPAN SN 1349-6476 J9 SOLA JI SOLA PY 2008 VL 4 BP 117 EP 120 DI 10.2151/sola.2008-030 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA V10JI UT WOS:000207459900030 ER PT S AU Yu, AW Novo-Gradac, AM Shaw, GB Unger, G Ramos-Izquierdo, LA Lukernire, A AF Yu, Anthony W. Novo-Gradac, Anne Marie Shaw, George B. Unger, Glenn Ramos-Izquierdo, Luis A. Lukernire, Alan BE Clarkson, WA Hodgson, NH Shori, RK TI The lunar orbiter laser altimeter (LOLA) laser transmitter - art. no. 68710D SO SOLID STATE LASERS XVII: TECHNOLOGY AND DEVICES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Solid State Lasers XVII CY JAN 20-24, 2008 CL San Jose, CA SP SPIE, Coherent Inc DE lunar orbiter laser altimeter; laser; topography; LIDAR; altimeter; space laser AB We present the final configuration of the space flight laser transmitter as delivered to the LOLA instrument. The laser consists of two oscillators with co-aligned outputs on a single bench, each capable of providing one billion plus shots. C1 [Yu, Anthony W.; Novo-Gradac, Anne Marie; Shaw, George B.] NASA, Goddard Space Flight Ctr, Laser & Electroopt Branch, Greenbelt, MD 20771 USA. RP Yu, AW (reprint author), NASA, Goddard Space Flight Ctr, Laser & Electroopt Branch, MC554, Greenbelt, MD 20771 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7046-1 J9 P SOC PHOTO-OPT INS PY 2008 VL 6871 BP D8710 EP D8710 DI 10.1117/12.779825 PG 4 WC Optics; Physics, Applied SC Optics; Physics GA BHQ84 UT WOS:000255549800010 ER PT S AU Balint, TS Cutts, JA Kolawa, EA Peterson, CE AF Balint, Tibor S. Cutts, James A. Kolawa, Elizabeth A. Peterson, Craig E. BE Fink, W TI Extreme environment technologies for space and terrestrial applications SO SPACE EXPLORATION TECHNOLOGIES SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Exploration Technologies CY MAR 17-18, 2008 CL Orlando, FL SP SPIE DE solar system exploration; extreme environments; technology; NASA AB Over the next decades, NASA's planned solar system exploration missions are targeting planets,moons and small bodies, where spacecraft would be expected to encounter diverse extreme environmental (EE) conditions throughout their mission phases. These EE conditions are often coupled. For instance, near the surface of Venus and in the deep atmospheres of giant planets, probes would experience high temperatures and pressures. In the Jovian system low temperatures are coupled with high radiation. Other environments include thermal cycling, and corrosion. Mission operations could also introduce extreme conditions, due to atmospheric entry heat flux and deceleration. Some of these EE conditions are not unique to space missions; they can be encountered by terrestrial assets from the fields of defense, oil and gas, aerospace, and automotive industries. In this paper we outline the findings of NASA's Extreme Environments Study Team, including discussions on state of the art and emerging capabilities related to environmental protection, tolerance and operations in EEs. We will also highlight cross cutting EE mitigation technologies, for example, between high g-load tolerant impactors for Europa and instrumented projectiles on Earth; high temperature electronics sensors on Jupiter deep probes and sensors inside jet engines; and pressure vessel technologies for Venus probes and sea bottom monitors. We will argue that synergistic development programs between these fields could be highly beneficial and cost effective for the various agencies and industries. Some of these environments, however, are specific to space and thus the related technology developments should be spearheaded by NASA with collaboration from industry and academia. C1 [Balint, Tibor S.; Cutts, James A.; Kolawa, Elizabeth A.; Peterson, Craig E.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Balint, TS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 301-170U, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 1 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7151-2 J9 PROC SPIE PY 2008 VL 6960 AR 696006 DI 10.1117/12.780389 PG 12 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BHY61 UT WOS:000257463400004 ER PT S AU Younse, P Aghazarian, H AF Younse, P. Aghazarian, Hrand BE Fink, W TI Steerable hopping six-legged robot SO SPACE EXPLORATION TECHNOLOGIES SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Exploration Technologies CY MAR 17-18, 2008 CL Orlando, FL SP SPIE DE hopping robot; hexapod; low-gravity exploration; lunar exploration; spring leg; coordinated leg motion; gyro stabilization AB A prototype of a steerable six-legged hopping robot for exploring low-gravity environments was designed, built, and tested. A 35 cm vertical hop was achieved, motorized steering of all six legs was demonstrated over a 40-degree range, and angled hopping was performed at a fixed 60-degree angle. Gyro stabilization was demonstrated through a hopping simulation of a modeled hopping robot with a controllable flywheel in lunar gravity. C1 [Younse, P.; Aghazarian, Hrand] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Younse, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM pauloj.younse@jpl.nasa.gov NR 17 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7151-2 J9 PROC SPIE PY 2008 VL 6960 AR 69600H DI 10.1117/12.781725 PG 12 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BHY61 UT WOS:000257463400013 ER PT S AU Younse, P AF Younse, P. BE Fink, W TI Launchable and retrievable tetherbot exploration system SO SPACE EXPLORATION TECHNOLOGIES SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Exploration Technologies CY MAR 17-18, 2008 CL Orlando, FL SP SPIE DE tethered robot; low-gravity exploration; lunar exploration; hopping robot; launchable robot; electric reel AB A launchable and retrievable tetherbot exploration system for low-gravity environments is proposed where a small, tethered robot is launched from a base lander or vehicle to a desired position up to 50 m away. When its exploration mission is complete, it hops vertically above the surface and is simultaneously reeled back in by the base vehicle while still above ground. Benefits include the ability to traverse long distances in short amounts of time and minimal energy expense independent of terrain roughness. This technique has the capability to reach locations too difficult, too dangerous, or unreachable by the base vehicle. Prototypes of a steerable six-legged hopping robot and electric reel were developed. A dynamic simulation demonstrated the capabilities of launching and tether retrieval. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Younse, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM paulo.j.younse@jpl.nasa.gov NR 9 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7151-2 J9 PROC SPIE PY 2008 VL 6960 AR 69600J DI 10.1117/12.781708 PG 12 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BHY61 UT WOS:000257463400015 ER PT S AU Maxwell, EB Cole, GS Scaringe, RP Didion, J AF Maxwell, Eric B. Cole, Gregory S. Scaringe, Robert P. Didion, Jeffrey BE ElGenk, MS TI Demonstration of a plug-and-play approach to spacecraft thermal control system design SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE spacecraft thermal control; heat pump; rover; heat rejection AB The thermal demands placed on interplanetary probes and rovers can vary wildly throughout the course of a given mission. As the electronics and other equipment on these rovers become more sophisticated, heat dissipation and thermal control become more of an issue. Further complicating the thermal control problem is the fact that the mission may not place the rover or probe in a location with a constant view of deep space, which would be the lowest temperature heat sink and would provide the best heat rejection potential. Mainstream Engineering, working with the Goddard Space Flight Center, has developed a high-lift heat pump capable of operating in microgravity that would allow the heat generated by electronic components or other subsystems to be radiated directly to the surface of a planet or moon in situations where there is no view of deep space. Performance data is presented for a prototype high-lift system for these applications. Also discussed is the potential for a reduction in the overall system mass for applications in which a high heat rejection temperature is not required. Ultimately, specialized active thermal control systems such as this one will allow a far greater range of missions and destinations for unmanned space vehicles. C1 [Maxwell, Eric B.; Cole, Gregory S.; Scaringe, Robert P.] Mainstream Engn Corp, 200 Yellow Pl, Rockledge, FL 32955 USA. [Didion, Jeffrey] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Maxwell, EB (reprint author), Mainstream Engn Corp, 200 Yellow Pl, Rockledge, FL 32955 USA. EM emaxwell@mainstream-engr.com FU NASA under Small Business Irmovative Research (SBIR) [NNX07CA75P] FX This work was done for NASA contract number NNX07CA75P under the Small Business Irmovative Research (SBIR) program. NR 9 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 21 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900003 ER PT S AU Park, C Sunada, E AF Park, Chanwoo Sunada, Eric BE ElGenk, MS TI Vapor compression hybrid two-phase loop technology for lunar surface applications SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE vapor compression; evaporation; two-phase; thermal; electronics; cooling; hybrid; compressor; pump; capillary; heat pump; temperature lift; lunar AB NASA's vision for Space Exploration that would return humans to the Moon by 2020 in preparation for human explorations of Mars. This requires innovative technical advances. The lunar mission requires a temperature-lift (heat pump) technology to reject waste heat to hot lunar surface (heat sink) environments during lunar daytime. The lunar outpost and Lunar Surface Access Module (LSAM) to operate anywhere during the hot lunar daytime require a high performance and energy-efficient, yet reliable refrigeration technology. A vapor compressor-driven hybrid two-phase loop was developed for such high temperature-lift applications. The vapor compression loop used an advanced porous wick evaporator capable of gravity-insensitive capillary phase separation and excess liquid management to achieve high temperature-lift, large-area, isothermal and high heat flux cooling capability and efficient compression. The high temperature lift will allow the lunar surface systems use compact radiators by increased heat rejection temperature. C1 [Park, Chanwoo] Adv Cooling Technol Inc, Lancaster, PA 17601 USA. [Sunada, Eric] Jet Prop Lab, Pasadena, CA 91109 USA. RP Park, C (reprint author), Adv Cooling Technol Inc, Lancaster, PA 17601 USA. EM chanwoo.park@l-act.com FU NASA SBIR Phase 1 [NNC07QA81P] FX This work was performed under a NASA SBIR Phase 1 program (Contract No.: NNC07QA81P). The authors wish to acknowledge the contributions of Mr. Andrew Radesky at ACT in testing and fabrication and Mr. Jeff Reichl in drawing of the vapor compression loop. NR 15 TC 3 Z9 4 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 37 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900005 ER PT S AU Johnston, JE Selvam, RP Silk, EA AF Johnston, Joseph E. Selvam, R. P. Silk, Eric A. BE ElGenk, MS TI Spray cooling modeling: Droplet sub-cooling effect on heat transfer SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE spray cooling; modeling; sub-cooling; thin film; multi-phase ID MULTIPLE-NOZZLE ARRAYS; SINGLE-NOZZLE; SIMULATION; SURFACES; IMPACT AB Spray cooling has become increasingly popular as a thermal management solution for high-heat flux (> 100 W/cm(2)) applications such as laser diodes and radars. Research has shown that using sub-cooled liquid can increase the heat flux from the hot surface. The objective of this study was to use a multi-phase numerical model to simulate the effect of a sub-cooled droplet impacting a growing vapor bubble in a thin (< 100 mu m) liquid film. The two-phase model captured the liquid-vapor interface using the level set method. The effects of surface tension, viscosity, gravity and phase change were accounted for by using a modification to the incompressible Navier-Stokes equations, which were solved using the finite difference method. The computed liquid-vapor interface and temperature distributions were visualized for better understanding of the heat removal process. To understand the heat transfer mechanisms of sub-cooled droplet impact on a growing vapor bubble, various initial droplet temperatures were modeled (from 20 degrees C below saturation temperature to saturation temperature). This may provide insights into how to improve the heat transfer in future spray cooling systems. C1 [Johnston, Joseph E.; Selvam, R. P.] Power Elect Leveling Solut LLC, 700 Res Blvd, Fayetteville, AR 72701 USA. [Johnston, Joseph E.; Selvam, R. P.] Univ Arkansas, Bell 4190, Fayetteville, AR 72701 USA. [Silk, Eric A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Johnston, JE (reprint author), Power Elect Leveling Solut LLC, 700 Res Blvd, Fayetteville, AR 72701 USA. EM rps@uark.edu RI selvam, Rathinam/H-7849-2013 FU SBIR; NASA Goddard Space Fight Center FX This work was performed at the University of Arkansas' Computational Mechanics Laboratory. Funding for this work was made possible through a SBIR grant awarded to Power Electronics Levehng Solutions, L.L.C. from the NASA Goddard Space Fight Center. NR 19 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 104 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900012 ER PT S AU Silk, EA AF Silk, Eric A. BE ElGenk, MS TI Investigation of pore size effect on spray cooling heat transfer with porous tunnels SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE spray cooling; enhanced surfaces; heat transfer ID TRANSFER MECHANISM; SURFACE-ROUGHNESS; FLUX CORRELATION; IMPACT; DIAMETER; FC-72 AB Previous studies have shown that spray cooling heat flux enhancement may be attained using enhanced surfaces (i.e., embedded surfaces). However, most enhanced surface spray cooling studies have been limited to extended surface structures. This study investigates the effect of porous tunnels (and pore size) on spray cooling heat flux. The pores were machined into the top of each heater block leading into the sub-surface tunnels. Pore diameters varied between 0.25 mm and 1.0 mm. Pore density was held constant for each of the enhanced surfaces tested. Each copper block had a projected cross- sectional area of 2.0 cm. Measurements were also obtained on a heater block with a flat surface for purposes of baseline comparison. A 2x2 nozzle array was used with PF-5060 as the working fluid. Thermal performance data was obtained under nominally degassed (chamber pressure of 41.4 kPa) conditions with a bulk fluid temperature of 20.5 degrees C. Results show that the highest critical heat flux (CHF) attained was 141 W/cm(2) using pores 1.0 mm in diameter. This gave an enhancement of 75% relative to the flat surface case. C1 NASA, Goddard Space Flight Ctr, Thermal Engn Technol Dev Grp, Greenbelt, MD 20771 USA. RP Silk, EA (reprint author), NASA, Goddard Space Flight Ctr, Thermal Engn Technol Dev Grp, Greenbelt, MD 20771 USA. EM Eric.A.Silk@nasa.gov NR 20 TC 3 Z9 3 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 112 EP 122 PG 11 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900013 ER PT S AU Semenov, SY Burke, KA AF Semenov, Sergey Y. Burke, Kenneth A. BE ElGenk, MS TI Titanium heat pipe thermal plane SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE beat pipe; vapor chamber; titanium; fuel cell AB A 95.3 mm by 95.3 mm by 1.0 mm thick titanium beat pipe thermal plane was constructed and tested. This thermal plane is being considered for passively removing heat from inside a PEM fuel cell stack. Titanium was selected because it is lightweight and is compatible with water, the working fluid inside the thermal plane. The total mass of the thermal plane is 26.3 grams; the effective density of the thermal plane is 2,900 kg/m(3). It was tested at heat flux levels as high as 60 W/cm(2). The thermal resistance at 40 W/cm(2) heat flux input is 0.9 degrees C/W. It was also shown to operate against 14 gravity. Several samples were fabricated, thermal tested and compared to the performance of identical thermal planes made of solid copper. The thermal performance of the titanium plane exceeded the performance of solid copper. In a weight comparison the titanium plane was three times lighter. Therefore, it is well suited for use in fuel cell thermal management solutions as well as space based applications where lightweight is the key factor in selecting a cooling system. C1 [Semenov, Sergey Y.] Thermacore Int Inc, Aerosp Engn, 780 Eden Rd, Lancaster, PA 17601 USA. [Burke, Kenneth A.] NASA, Glenn Res Ctr, Power & Propuls Technol Div, Electrochem Branch, Cleveland, OH 44135 USA. RP Semenov, SY (reprint author), Thermacore Int Inc, Aerosp Engn, 780 Eden Rd, Lancaster, PA 17601 USA. EM s.y.semenov@thermacore.com NR 5 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 131 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900015 ER PT S AU Lueck, DE Captain, JE Gibson, TL Peterson, BV Berger, CM AF Lueck, Dale E. Captain, Janine E. Gibson, Tracy L. Peterson, Barbara V. Berger, Cristina M. BE ElGenk, MS TI Selection, development and results for the RESOLVE Regolith Volatiles Characterization analytical system SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE Gas Chromatography; GC; RESOLVE; Lunar Volatiles Analysis ID LUNAR POLES; WATER ICE AB The RESOLVE project requires an analytical system to identify and quantitate the volatiles released from a lunar drill core sample as it is crushed and heated to 150 degrees C. The expected gases and their range of concentrations were used to assess Gas Chromatography (GC) and Mass Spectrometry (MS), along with specific analyzers for use on this potential lunar lander. The ability of these systems to accurately quantitate water and hydrogen in an unknown matrix led to the selection of a small MEMS commercial process GC for use in this project. The modification, development and testing of this instrument for the specific needs of the project is covered. C1 [Lueck, Dale E.; Captain, Janine E.] NASA, Div Appl Sci, Appl Technol Directorate, John F Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. [Gibson, Tracy L.; Peterson, Barbara V.; Berger, Cristina M.] Artie Slope Res Corp Aerosp, Appl Sci & Technol, Kennedy Space Ctr, FL 32899 USA. RP Lueck, DE (reprint author), NASA, Div Appl Sci, Appl Technol Directorate, John F Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. EM dale.e.lueck@nasa.gov FU NASA Exploration Technology Development Program FX The author thanks the NASA Exploration Technology Development Program for their continued funding for this program, Jerry Sanders at JSC for his tireless promotion of ISRU, and Bill Larson at KSC for his leadership and behef in the Applied Sciences Division at KSC. NR 5 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 149 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900017 ER PT S AU Balasubramaniam, R Hegde, U Gokoglu, S AF Balasubramaniam, R. Hegde, U. Gokoglu, S. BE ElGenk, MS TI Carbothermal processing of lunar regolith using methane SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE carbothermal processing; lunar regolith; pyrolysis; kinetics AB The processing of lunar regolith for the production of oxygen is a key component of the In-Situ Resource Utilization plans currently being developed by NASA. Among various candidate processes, the modeling of oxygen production by hydrogen reduction, molten salt electrolysis, and carbothermal processing are presently being pursued. In the carbothermal process, a portion of the surface of the regolith in a container is heated by exposure to a heat source such as a laser beam or a concentrated solar heat flux, so that a small zone of molten regolith is established. The molten zone is surrounded by solid regolith particles that are poor conductors of heat. A continuous flow of methane is maintained over the molten regolith zone. Our model is based on a mechanism where methane pyrolyzes when it comes in contact with the surface of the hot molten regolith to form solid carbon and hydrogen gas. Carbon is deposited on the surface of the melt, and hydrogen is released into the gas stream above the melt surface. We assume that the deposited carbon mixes in the molten regolith and reacts with metal oxides in a reduction reaction by which gaseous carbon monoxide is liberated. Carbon monoxide bubbles through the melt and is released into the gas stream. Oxygen is produced subsequently by (catalytically) processing the carbon monoxide downstream. In this paper, we discuss the development of a chemical conversion model of the carbothermal process to predict the rate of production of carbon monoxide. C1 [Balasubramaniam, R.; Hegde, U.] NASA, Glenn Res Ctr, Natl Ctr Space Explorat Res, Cleveland, OH 44135 USA. [Gokoglu, S.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Balasubramaniam, R (reprint author), NASA, Glenn Res Ctr, Natl Ctr Space Explorat Res, Cleveland, OH 44135 USA. EM bala@grc.nasa.gov FU NASA Glenn Research Center [NCC3-975] FX R. Balasubramaniam and U. Hegde were supported by a Cooperative Agreement NCC3-975 from NASA Glenn Research Center to the National Center for Space Exploration Research. The authors would like to thank K. Sacksteder and D. Linne of NASA Glenn Research Center and E. Santiago-Maldonaldo of NASA Kennedy Space Center for discussions and comments during the course of the investigation. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 157 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900018 ER PT S AU Stefanescu, DM Curreri, PA Sen, S AF Stefanescu, Doru M. Curreri, Peter A. Sen, Subhayu BE ElGenk, MS TI Molten materials transfer and handling on the lunar surface SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE electrolytic reduction; lunar resource utilization; molten materials transfer AB Electrolytic reduction processes as a means to provide pure elements for lunar resource utilization have the potential of removing all the oxygen from the lunar soil for use in life support and for propellant. Electrochemical reduction also provides a direct path for the production of pure metals and silicon which can be utilized for in situ manufacturing and power production. Some of the challenges encountered in the electrolytic reduction processes include the feeding of the electrolytic cell (the transfer of electrolyte containing lunar soil), the withdrawal of reactants and refined products such as the liquid iron-silicon alloy with a number of impurities, and the spent regolith slag, produced in the hot electrolytic cell for the reduction of lunar regolith. The paper discusses some of the possible solutions to the challenges of handling molten materials on the lunar surface, as well as the path toward the construction and testing of a proof of concept facility. C1 [Stefanescu, Doru M.] Ohio State Univ, Dept Mat Sci & Engn, 116 W 19Th Ave, Columbus, OH 43210 USA. [Curreri, Peter A.] NASA, Marshall Space Flight Ctr, Huntsville, AL USA. [Sen, Subhayu] BAE Syst, Huntsville, AL USA. RP Stefanescu, DM (reprint author), Ohio State Univ, Dept Mat Sci & Engn, 116 W 19Th Ave, Columbus, OH 43210 USA. RI Stefanescu, Doru/G-8101-2012; OI Stefanescu, Doru M./0000-0001-5544-8396 NR 12 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 162 EP + PG 3 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900019 ER PT S AU Schofield, EC Sen, S O'Dell, JS AF Schofield, Elizabeth C. Sen, Subhayu O'Dell, J. Scott BE ElGenk, MS TI Plasma processing of lunar regolith simulant for diverse applications SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE plasma processing; lunar regolith simulant; JSC-1; oxygen evolution; reduction of metals; in-situ manufacturing AB Versatile manufacturing technologies for extracting resources from the moon are needed to support future space missions. Of particular interest is the production of gases and metals from lunar resources for life support, propulsion, and in-space fabrication. Deposits made from lunar regolith could yield highly emissive coatings and near net shaped parts for replacement or repair of critical components. Equally important is development of high fidelity lunar simulants for ground based validation of potential lunar surface operations. Described herein is an innovative plasma processing technique for in-situ production of gases, metals, coatings, and deposits from lunar regolith, and synthesis of high fidelity lunar simulant from NASA issued lunar simulant JSC-1. Initial plasma reduction trials of JSC-1 lunar simulant have indicated production of metallic iron and magnesium. Evolution of carbon monoxide has been detected subsequent to reduction of the simulant using the plasma process. Plasma processing of the simulant has also resulted in glassy phases resembling the volcanic glass and agglutinates found in lunar regolith. Complete and partial glassy phase deposits have been obtained by varying the plasma process variables. Experimental techniques, product characterization, and process gas analysis will be discussed. C1 [Schofield, Elizabeth C.; O'Dell, J. Scott] Plasma Proc, 4914 Moores Mill Rd, Huntsville, AL 35811 USA. [Sen, Subhayu] NASA, BAE Syst Inc, Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Schofield, EC (reprint author), Plasma Proc, 4914 Moores Mill Rd, Huntsville, AL 35811 USA. EM eschofield@plasmapros.com FU NASA SBIR FX Funding for this work was provided by the NASA SBIR program. The authors gratefully acknowledge the assistance of Dr. Ed Golla, Dr Arvind Agarwal, and Dr. Chandra Ray NR 9 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 170 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900020 ER PT S AU Hegde, U Balasubramaniam, R Gokoglu, S AF Hegde, U. Balasubramaniam, R. Gokoglu, S. BE ElGenk, MS TI Analysis of thermal and reaction times for hydrogen reduction of lunar regolith SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE hydrogen reduction; ilmenite; lunar regolith; shrinking core ID OXYGEN AB System analysis of oxygen production by hydrogen reduction of lunar regolith has shown the importance of the relative time scales for regolith heating and chemical reaction to overall performance. These values determine the sizing and power requirements of the system and also impact the number and operational phasing of reaction chambers. In this paper, a Nusselt number correlation analysis is performed to determine the heat transfer rates and regolith heat up times in a fluidized bed reactor heated by a central heating element (e.g., a resistively heated rod, or a solar concentrator heat pipe). A coupled chemical and transport model has also been developed for the chemical reduction of regolith by a continuous flow of hydrogen. The regolith conversion occurs on the surfaces of and within the regolith particles. Several important quantities are identified as a result of the above analyses. Reactor scale parameters include the void fraction (i.e., the fraction of the reactor volume not occupied by the regolith particles) and the residence time of hydrogen in the reactor. Particle scale quantities include the particle Reynolds number, the Archimedes number, and the time needed for hydrogen to diffuse into the pores of the regolith particles. The analysis is used to determine the heat up and reaction times and its application to NASA's oxygen production system modeling tool is noted. C1 [Hegde, U.; Balasubramaniam, R.] Natl Ctr Space Explorat Res, Cleveland, OH 44135 USA. [Gokoglu, S.] NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. RP Hegde, U (reprint author), Natl Ctr Space Explorat Res, Cleveland, OH 44135 USA. EM uday.hegde@grc.nasa.gov FU NASA [NCC3-975]; National Center for Space Exploration Research FX U. Hegde and R. Balasubramaniam were supported under NASA Cooperative Agreement NCC3-975 with the National Center for Space Exploration Research. The authors greatly appreciate the encouragement and insights offered by K. Sacksteder and D. Lirme of NASA Glerm Research Center, and useful discussions with E. SantiagoMaldonado of NASA Kermedy Space Center during the course of this work. NR 11 TC 0 Z9 0 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 195 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900023 ER PT S AU Mueller, RP King, RH AF Mueller, R. P. King, R. H. BE ElGenk, MS TI Trade study of excavation tools and equipment for lunar outpost development and ISRU SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE lunar outpost; lunar soil excavators and excavation; decision analysis; trade study AB The NASA Lunar Architecture Team (LAT) has developed a candidate architecture to establish a lunar outpost that includes in-situ resource utilization (ISRU). Outpost development requires excavation for landing and launch sites, roads, trenches, foundations, radiation and thermal shielding, etc. Furthermore, ISRU requires excavation as feed stock for water processing and oxygen production plants. The design environment for lunar excavation tools and equipment including low gravity, cost of launching massive equipment, limited power, limited size, high reliability, and extreme temperatures is significantly different from terrestrial excavation equipment design environment. Consequently, the lunar application requires new approaches to developing excavation tools and equipment in the context of a systems engineering approach to building a Lunar Outpost. Several authors have proposed interesting and innovative general excavation approaches in the literature, and the authors of this paper will propose adaptations and/or new excavation concepts specific to the Lunar Outpost. The requirements for excavation from the LAT architecture will be examined and quantified with corresponding figures of merit and evaluation criteria. This paper will evaluate the proposed approaches using traditional decision making with uncertainty techniques. C1 [Mueller, R. P.] NASA, Adv Syst Div, M S KT C, Kennedy Space Ctr, FL 32899 USA. [King, R. H.] Colorado Sch Mines, Div Engn, Golden, CO 80401 USA. RP Mueller, RP (reprint author), NASA, Adv Syst Div, M S KT C, Kennedy Space Ctr, FL 32899 USA. EM rking@mines.edu NR 4 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 237 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900028 ER PT S AU Linne, DL Freeh, JE Abercromby, AFJ AF Linne, Diane L. Freeh, Joshua E. Abercromby, Andrew F. J. BE ElGenk, MS TI Commonality of electrolysis sub-systems for ISRU, power, and life support of a lunar outpost SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE in-situ resource utilization; energy storage; pressurized rovers; lunar bases AB As details of an eventual lunar outpost evolve, it is clear that the various surface systems will have some common components. For example, fuel cells for nighttime power and long-range rovers, the life support system, and the in-situ resource utilization system will all generate water that will need to be electrolyzed into oxygen and hydrogen. While these various systems may require electrolysis at different rates, there are many benefits to developing a common system. These benefits include reduced development costs, commonality of spares, and the ability to provide critical backup. This paper evaluates the electrolysis sub-system requirements for the four surface systems and the preferred design for each user. We then evaluate the advantages and disadvantages of relying on a single electrolysis sub-system for all four surface systems. We also evaluate whether some or all of the electrolysis functions could be centralized at one surface system. C1 [Linne, Diane L.; Freeh, Joshua E.] NASA, Glen Res Ctr, Houston, TX 77058 USA. [Abercromby, Andrew F. J.] Wyle,1290 Hercules, Houston, TX 77058 USA. RP Linne, DL (reprint author), NASA, Glen Res Ctr, Houston, TX 77058 USA. EM Diane.L.Linne@nasa.gov NR 7 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 252 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900030 ER PT S AU Everingham, MR Pelster, N Mueller, RP Davidian, K AF Everingham, Matthew R. Pelster, Nicholas Mueller, Robert P. Davidian, Kenneth BE ElGenk, MS TI Preparation and handling large quantities of JSC-1A lunar regolith simulant for the 2007 Regolith Excavation Challenge SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE moon; lunar; regolith; compaction; simulant; JSC-1A; excavation; ISRU; analog AB The 2007 Regolith Excavation Challenge, a NASA Centennial Challenge, was conducted in May 2007 at Santa Maria, California. This lunar analog activity was intended to encourage competitors to design innovative excavation systems that can accommodate the unique properties of lunar regolith while performing within the limitations of operational constraints. For the challenge, the excavation systems were required to be autonomous, weigh less than 40 kilograms, operate on less than 30 watts, and excavate more than 150 kg of regolith in 30 minutes. In order to support the competition event, eight tons of JSC-1A lunar regolith simulant was acquired. A large "sand box" was built to contain the regolith simulant for the competition event. Handling the large quantities of simulant introduced several challenges and several insightful observations (dust, stability, etc.) were made that could potentially benefit other research employing lunar regolith simulant. One of the most challenging aspects of the competition was the attempt to best replicate lunar regolith compaction with the simulant. Due to the size of the "sand box" and the amount of simulant, many methods of densification were considered prior to the event. The results revealed good compaction can be obtained in large test bins of simulant presenting an opportunity for using this analog in other important lunar exploration systems tests. C1 [Everingham, Matthew R.; Pelster, Nicholas] California Space Author, 3201 Airpk Dr, San Maria, CA 93455 USA. [Everingham, Matthew R.; Pelster, Nicholas] Caliprnia Space Educ & Workprce Inst, Pasadena, CA 91105 USA. [Mueller, Robert P.] NASA, Kennedy Space Ctr, FL 32899 USA. [Davidian, Kenneth] NASA, Washington, DC 20546 USA. RP Everingham, MR (reprint author), California Space Author, 3201 Airpk Dr, San Maria, CA 93455 USA. EM matt.everingham@califomiaspaceauthority.org NR 2 TC 0 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 268 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900032 ER PT S AU Werner, J Mason, L AF Werner, James Mason, Lee BE ElGenk, MS TI An affordable test approach for lunar Fission Surface Power Systems SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE nuclear; space; test; fast; reactors AB Safety, performance and affordability are the key drivers for the design selection of a Fission Surface Power System (FSPS) and planning for an affordable test approach. An affordable reactor power system can be built by leveraging the design and operating experience of similar reactor and power conversion systems. The reactor technology considered for such a system must represent relatively low technology risk. That is, the materials, fuels, components and operating levels must be drawn from similar systems that have current operating experience and can be easily demonstrated with minimal technology development effort. The operational experience and significant database for the performance of the material, fuel and components are key to developing an affordable test approach. An objective in designing an affordable reactor and associated test approach is to avoid an extensive fuel and reactor technology qualification effort and, instead, rely on existing databases and experience wherever practical. Likewise, limiting the operating temperatures and radiation levels for the materials and components to conservative levels where high confidence exists in its operating performance is essential. The objective of this paper is to describe a test approach for a lunar fission surface power system that is affordable and yet adequately provides the safety and performance data needed to design and qualify such a system for operation on the lunar soil. C1 [Werner, James] Idaho Natl Lab, Idaho Falls, ID 83415 USA. [Mason, Lee] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Werner, J (reprint author), Idaho Natl Lab, Idaho Falls, ID 83415 USA. FU U.S. Department of Energy [DE-AC07- 99ID13727] FX This research was supported in part by the U.S. Department of Energy, Office of Nuclear Science and Technology,Division of Radioisotope Power Systems, under Contract No. DE-AC07- 99ID13727. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 301 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900036 ER PT S AU Reid, RS Pearson, JB AF Reid, Robert S. Pearson, J. Boise BE ElGenk, MS TI Gravity scaling of a power reactor water shield SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE fission; reactor; structural; shield; material AB Water based reactor shielding is being considered as an affordable option for potential use on initial lunar surface reactor power systems. Heat dissipation in the shield from nuclear sources must be rejected by an auxiliary thermal hydraulic cooling system. The mechanism for transferring heat through the shield is natural convection between the core surface and an array of thermosyphon radiator elements. Natural convection in a 100 kWt lunar surface reactor shield design has been previously evaluated at lower power levels (Pearson, 2006). The current baseline assumes that 5.5 kW are dissipated in the water shield, the preponderance on the core surface, but with some volumetric beating in the naturally circulating water as well. This power is rejected by a radiator located above the shield with a surface temperature of 370 K. A similarity analysis on a water-based reactor shield is presented examining the effect of gravity on free convection between a radiation shield inner vessel and a radiation shield outer vessel boundaries. Two approaches established similarity: 1) direct scaling of Rayleigh number equates gravity-surface heat flux products, 2) temperature difference between the wall and thermal boundary layer held constant on Earth and the Moon. Nussult number for natural convection (laminar and turbulent) is assumed of form Nu = CRan. These combined results estimate similarity conditions under Earth and Lunar gravities. The influence of reduced gravity on the performance of thermosyphon beat pipes is also examined. C1 [Reid, Robert S.; Pearson, J. Boise] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Reid, RS (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 307 EP 315 PG 9 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900037 ER PT S AU Schoenfeld, MP Anghale, S AF Schoenfeld, Michael P. Anghale, Sainim BE ElGenk, MS TI Radiolysis concerns for water shielding in fission surface power applications SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE radiolysis; water shield; water decomposition AB This paper presents an overview of radiolysis concerns with regard to water shields for fission surface power. A review of the radiolysis process is presented and key parameters and trends are identified. From this understanding of the radiolytic decomposition of water, shield pressurization and corrosion are identified as the primary concerns. Existing experimental and modeling data addressing concerns are summarized. It was found that radiolysis of pure water in a closed volume results in minimal, if any net decomposition, and therefore reduces the potential for shield pressurization and corrosion. C1 [Schoenfeld, Michael P.] NASA, George C Marshall Space Flight Ctr, MSFC, ER24, Huntsville, AL 35812 USA. [Anghale, Sainim] Univ Florida, Innovat Space Power & Propuls Inst, Gainesville, FL 32611 USA. RP Schoenfeld, MP (reprint author), NASA, George C Marshall Space Flight Ctr, MSFC, ER24, Huntsville, AL 35812 USA. EM michael.p.schoenfeld@nasa.gov NR 12 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 337 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900040 ER PT S AU Razzaghi, AI Di Pietro, DA Quinn, DA Simon-Miller, AA Tompkins, SD AF Razzaghi, Andrea I. Di Pietro, David A. Quinn, David A. Simon-Miller, Amy A. Tompkins, Steven D. BE ElGenk, MS TI Mission concepts for studying enceladus SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE enceladus orbiter; enceladus lander; Saturn orbiter AB Enceladus, the tiny moon orbiting Saturn, has intrigued scientists through recent discoveries of unique surface features and a south-pole geyser. These discoveries from the Cassini mission have increased the importance of Enceladus as a target for future missions. Upon the recommendation of the NASA Advisory Council Planetary Science Subcommittee and the Outer Planets Assessment Group, NASA Headquarters' Planetary Science Division cominissioned a pre-phase A study of Flagship missions to Enceladus. The trade space for this architecture study included single Enceladus flybys, Enceladus orbiters, Saturn orbiters that fly by Enceladus, landers, impactors and sample return missions. Technologies considered included solar electric propulsion systems and radioisotope power systems. Within this trade space, several promising concepts, including Saturn orbiters, Enceladus orbiters and landers, were developed. C1 [Razzaghi, Andrea I.; Di Pietro, David A.; Quinn, David A.; Simon-Miller, Amy A.; Tompkins, Steven D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Razzaghi, AI (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. OI Simon, Amy/0000-0003-4641-6186 NR 3 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 388 EP 395 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900045 ER PT S AU Harmon, BA Lavery, DB AF Harmon, B. Alan Lavery, David B. BE ElGenk, MS TI NASA radioisotope power systems program update SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE space nuclear power; radioisotope power system; radioisotope thermoelectric generator; RTG; Stirling engine; Stirling convertor; advanced Stirling radioisotope generator; SRG; ASRG AB The use of Radioisotope Power Systems (RPS) represents a critical capability for exploration of the Solar System. RPS have been used for decades to power deep space missions and sometimes for the operation of landers or rovers on Mars. Modest power needs (5 AU) make them attractive, and, in most cases, essential for a variety of missions. Even close by, such as on the surface of the Moon or Mars, RPS enhances operational capability. NASA's strategic planning now contemplates more ambitious missions than those of the past, with the likelihood of increasingly severe or more diverse environments in which to contend. We are at a crossroads in the application of radioisotope power, thanks partially to progress made, but also due to the realities of budget constraints and the availability of plutonium-238 fuel. Within a few years, investments in power conversion technologies could yield next generation flight systems with capability for multiple environments, and improved efficiency and specific power. However, for RPS, given the demands on reliability and system longevity (15+ years), infusion of any new RPS technology is the challenge. We review progress made during the past year in development of RPS and note applications in NASA's Science Plan (2007). C1 [Harmon, B. Alan] NASA Headquarters, Radio Power Syst Off, 300 E St SW, Washington, DC 20546 USA. [Harmon, B. Alan; Lavery, David B.] NASA, Sci Miss Directorate, Washington, DC 20546 USA. RP Harmon, BA (reprint author), NASA Headquarters, Radio Power Syst Off, 300 E St SW, Washington, DC 20546 USA. EM bruce.a.harmon@nasa.gov NR 15 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 396 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900046 ER PT S AU Bragg-Sitton, SM Dickens, R Dixon, D Reid, R Adams, M Davis, J AF Bragg-Sitton, Shannon M. Dickens, Ricky Dixon, David Reid, Robert Adams, Mike Davis, Joe BE ElGenk, MS TI Advanced thermal simulator testing: Thermal analysis and test results SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE non-nuclear testing; thermal simulators; electrical heaters ID DESIGN AB Work at the NASA Marshall Space Flight Center seeks to develop high fidelity, electrically heated thermal simulators that represent fuel elements in a nuclear reactor design to support non-nuclear testing applicable to the potential development of a space nuclear power or propulsion system. Comparison between the fuel pins and thermal simulators is made at the outer fuel clad surface, which corresponds to the outer sheath surface in the thermal simulator. The thermal simulators that are currently being tested correspond to a liquid metal cooled reactor design that could be applied for Lunar surface power. These simulators are designed to meet the geometric and power requirements of a proposed surface power reactor design, accommodate testing of various axial power profiles, and incorporate imbedded instrumentation. This paper reports the results of thermal simulator analysis and testing in a bare element configuration, which does not incorporate active heat removal, and testing in a water-cooled calorimeter designed to mimic the heat removal that would be experienced in a reactor core. C1 [Bragg-Sitton, Shannon M.; Dickens, Ricky; Dixon, David; Reid, Robert; Adams, Mike; Davis, Joe] NASA, George C Marshall Space Flight Ctr, Nucl Syst Branch, MSFC, Huntsville, AL 35812 USA. RP Bragg-Sitton, SM (reprint author), NASA, George C Marshall Space Flight Ctr, Nucl Syst Branch, MSFC, ER24, Huntsville, AL 35812 USA. NR 16 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 403 EP 414 PG 12 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900047 ER PT S AU Polzin, KA Godfroy, TJ AF Polzin, Kurt A. Godfroy, Thomas J. BE ElGenk, MS TI Flow components in a NaK test loop designed to simulate conditions in a nuclear surface power reactor SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE non-nuclear testing; electromagnetic pump; electromagnetic flow sensor; liquid-metal coolant AB A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-ENIF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 34.5 kPa, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.114 m(3)/hr. C1 [Polzin, Kurt A.; Godfroy, Thomas J.] NASA, George C Marshall Space Flight Ctr, Prop Res & Technol Applicat Branch, MSFC, Huntsville, AL 35812 USA. RP Polzin, KA (reprint author), NASA, George C Marshall Space Flight Ctr, Prop Res & Technol Applicat Branch, MSFC, ER24, Huntsville, AL 35812 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 423 EP 429 PG 7 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900049 ER PT S AU Ha, CT Fernandez, R Comford, SL Feather, MS AF Ha, Chuong T. Fernandez, Rene Comford, Steven L. Feather, Martin S. BE ElGenk, MS TI Advanced Stirling radioisotope generator Design processes, reliability analyses impacts, and extended operation tests SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE Stirling; reliability; Weibayes; DDP AB NASA is currently funding an effort involving the Department of Energy (DOE), Lockheed Martin (LM), Glenn Research Center (GRC), and Sunpower (SP), Inc. to develop a high specific power Advanced Stirling Radioisotope Generator (ASRG). GRC and SP are responsible for providing the Stirling convertor, white LM is responsible for the generator housing, controller, and system integration. GRC also provides supporting technologies for various components as well as extended operation testing, both in air and in a thermal vacuum environment. Because of the 17-year life requirement of the ASRG, reliability considerations are the main design driver. Components such as the heater head, fasteners, magnets, and planar spring have been studied to ensure high reliability. To encompass unique design features, long lifetimes and extreme environmental conditions, both reliability analyses and qualification tests are used to support the design process. This paper presents an overview of the ASRG reliability approach and the impact of the Reliability Working Group (RWG) on the recently finished design effort. It also provides a summary of current and planned extended operation tests, specifically targeted to demonstrate long-life capability and to support further reliability assessment. In the event of no, or minimal failures during these extended tests, a Weibayes approach will be used to create a trend of improving reliability predictions. C1 [Ha, Chuong T.] Lockheed Martin Space Syst, Sunnyvale, CA 94089 USA. [Fernandez, Rene] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Comford, Steven L.; Feather, Martin S.] California Inst Technol, NASA Jet Prop Lab, Pasadena, CA 91109 USA. RP Ha, CT (reprint author), Lockheed Martin Space Syst, Sunnyvale, CA 94089 USA. EM chuong.ha@lmco.com FU Glerm Research Center; Jet Propulsion Laboratory; California Institute of Technology; U.S. Department of Energy; National Aeronautics and Space Administration FX This work was carried out at Lockheed Martin, Glerm Research Center, and the Jet Propulsion Laboratory, California Institute of Technology, and was sponsored by the U.S. Department of Energy and the National Aeronautics and Space Administration. The authors also wish to acknowledge the contribution and technical collaboration of other members of the ASRG Reliability Working Group. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 458 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900054 ER PT S AU Kerslake, TW AF Kerslake, Thomas W. BE ElGenk, MS TI Lunar surface-to-surface power transfer SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE lunar surface; power transmission; power cables; solid-state laser power; radiofrequency power AB A human lunar outpost, under NASA study for construction in the 2020's, has potential requirements to transfer electric power up to 50-kW across the lunar surface from 0.1 to 10-km distances. This power would be used to operate surface payloads located remotely from the outpost and/or outpost primary power grid. This paper describes concept designs for state-of-the-art technology power transfer subsystems including AC or DC power via cables, beamed radio frequency power and beamed laser power. Power transfer subsystem mass and performance are calculated and compared for each option. A simplified qualitative assessment of option operations, hazards, costs and technology needs is also described. Based on these concept designs and performance analyses, a DC power cabling subsystem is recommended to minimize subsystem mass and to minimize mission and programmatic costs and risks. Avenues for additional power transfer subsystem studies are recommended. C1 NASA, Mission & Syst Anal Div, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Kerslake, TW (reprint author), NASA, Mission & Syst Anal Div, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 466 EP 473 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900055 ER PT S AU Ballard, RO AF Ballard, Richard O. BE ElGenk, MS TI Future NTP development synergy leveraged from current J-2X engine development SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE nuclear thermal propulsion; NTP; lessons learned; fundamental root cause; risk mitigation AB This paper is a discussion of how the many long-lead development elements required for the realization of a future nuclear thermal propulsion (NTP) system can be effectively leveraged from the ongoing work being conducted on the J-2X engine program for the Constellation Program. Development studies conducted to date for NTP forward planning have identified a number of technical areas that will require advancement to acceptable technology readiness levels (TRLs) before they can be utilized in NTP system development. These include high-temperature, high-area ratio nozzle extension; long-life, low-NPSP turbomachinery; and low-boiloff propellant management, and a qualified nuclear fuel element. The current J-2X program is working many of these areas that can be leveraged to support NTP development in a highly compatible and synergistic fashion. In addition to supporting technical development, there are other programmatic issues being worked in the J-2X program that can be leveraged by a future NTP development program. These include compliance with recently-evolved space system requirements such as human-rating, fault tolerance and fracture control. These and other similar mandatory system requirements have been adopted by NASA and can result in a significant technical impact beyond elevation of the root technologies required by NTP. Finally, the exploitation of experience, methodologies, and procedures developed by the J-2X program in the areas of verification, qualification, certification, altitude simulation testing, and facility definition will be especially applicable to a future NTP system. The similarities in system mission (in-space propulsion) and operational environment (vacuum, zero-gee) between J-2X and NTP make this highly synergistic. Thus, it can be shown that the collective benefit of leveraging experience and technologies developed during the J-2X program can result in significant savings in development cost and schedule for NTP. C1 NASA, George C Marshall Space Flight Ctr, Liquid Engine & Main Propul Syst Branch, Huntsville, AL 35812 USA. RP Ballard, RO (reprint author), NASA, George C Marshall Space Flight Ctr, Liquid Engine & Main Propul Syst Branch, Huntsville, AL 35812 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 526 EP 532 PG 7 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900062 ER PT S AU Emrich, WJ AF Emrich, William J., Jr. BE ElGenk, MS TI Nuclear thermal rocket element environmental simulator (NTREES) SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE nuclear thermal rocket; fuel element; testing AB To support a potential future development of a nuclear thermal rocket engine, a state-of-the-art non nuclear experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The test device simulates the environmental conditions (minus the radiation) to which nuclear rocket fuel components could be subjected during reactor operation. Test articles mounted in the simulator are inductively heated in such a manner as to accurately reproduce the temperatures and heat fluxes normally expected to occur as a result of nuclear fission while at the same time being exposed to flowing hydrogen. This project is referred to as the Nuclear Thermal Rocket Element Environment Simulator or NTREES. The NTREES device is located at the Marshall Space flight Center in a laboratory which has been modified to accommodate the high powers required to heat the test articles to the required temperatures and to handle the gaseous hydrogen flow required for the tests. Other modifications to the laboratory include the installation of a nitrogen gas supply system and a cooling water supply system. During the design and construction of the facility, every effort was made to comply with all pertinent regulations to provide assurance that the facility could be operated in a safe and efficient manner. The NTREES system can currently supply up to 50 kW of inductive heating to the fuel test articles, although the facility has been sized to eventually allow test article heating levels of up to several megawatts. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Emrich, WJ (reprint author), NASA, George C Marshall Space Flight Ctr, MS ER24, Huntsville, AL 35812 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 541 EP 548 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900064 ER PT S AU Shin, EE Scheiman, D Cybulski, M Quade, D Inghram, L Burke, C AF Shin, E. Eugene Scheiman, Dan Cybulski, Michelle Quade, Derek Inghram, Linda Burke, Chris BE ElGenk, MS TI Validation of organics for advanced Stirling convertor (ASC) SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE Stirling convertors; organics; validation; process optimization; bonding; performance; durability AB Organic materials are an essential part of the Advanced Stirling Convertor (ASC) construction as adhesives, potting, wire insulation, lubrication coatings, bobbins, bumpers, insulators, thread lockers. Since a long lifetime of such convertors to be used in the Advanced Stirling Radioisotope Generator (ASRG), sometimes up to 17 years, is required in various space applications such as Mars rovers, deep space missions, and lunar surface power, performance, durability and reliability of those organics should be critically evaluated in every possible material-process-fabricationservice environment relations. The objective of this study was to evaluate, validate, and recommend organics for use in ASCs. Systematic and extensive evaluation methodologies were developed and conducted for various organic materials. The overall efforts dealing with organics materials for the last several years are summarized in the key areas, e.g., process-fabrication optimization, adhesive bonding integrity, outgassing, thermal stability, and durability. C1 [Shin, E. Eugene; Scheiman, Dan; Cybulski, Michelle; Quade, Derek; Inghram, Linda; Burke, Chris] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Shin, EE (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 11 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 570 EP 581 PG 12 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900067 ER PT S AU Schreiber, JG Thieme, LG AF Schreiber, Jeffrey G. Thieme, Lanny G. BE ElGenk, MS TI GRC supporting technology for NASA's advanced Stirling radioisotope generator (ASRG) SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE Stirling; radioisotope; space power; reliability; organics; magnets; EMI/EMC; structural dynamics AB From 1999-2006, the Glenn Research Center (GRC) supported a NASA project to develop a high-efficiency, nominal 110-We Stirling Radioisotope Generator (SRG110) for potential use on NASA missions. Lockheed Martin was selected as the System Integration Contractor for the SRG110, under contract to the Department of Energy (DOE). The potential applications included deep space missions, and Mars rovers. The project was redirected in 2006 to make use of the Advanced Stirling Convertor (ASC) that was being developed by Sunpower, Inc. under contract to GRC, which would reduce the mass of the generator and increase the power output. This change would approximately double the specific power and result in the Advanced Stirling Radioisotope Generator (ASRG). The SRG110 supporting technology effort at GRC was replanned to support the integration of the Sunpower convertor and the ASRG. This paper describes the ASRG supporting technology effort at GRC and provides details of the contributions in some of the key areas. The GRC tasks include convertor extended-operation testing in air and in thermal vacuum environments, heater head life assessment, materials studies, permanent magnet characterization and aging tests, structural dynamics testing, electromagnetic interference and electromagnetic compatibility characterization, evaluation of organic materials, reliability studies, and analysis to support controller development. C1 [Schreiber, Jeffrey G.; Thieme, Lanny G.] NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Schreiber, JG (reprint author), NASA, Glenn Res Ctr Lewis Field, MS 301-2,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 582 EP 592 PG 11 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900068 ER PT S AU Birchenoughl, A Hervol, D AF Birchenoughl, Arthur Hervol, David BE ElGenk, MS TI Test results from a simulated high voltage lunar power transmission line SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE energy conversion; high-current and high-voltage technology AB The Alternator Test Unit (ATU) in the Lunar Power System Facility (LPSF) located at the NASA Glenn Research Center (GRC) in Cleveland, OH was modified to simulate high voltage transmission capability. The testbed simulated a I kin transmission cable length from the ATU to the LPSF using resistors and inductors installed between the distribution transformers. Power factor correction circuitry was used to compensate for the reactance of the distribution system to improve the overall power factor. This test demonstrated that a permanent magnet alternator can successfully provide high frequency AC power to a lunar facility located at a distance. C1 [Birchenoughl, Arthur] NASA, Glenn Res Ctr, Power Syst Dev Branch, Power & Avion Div, Cleveland, OH 44135 USA. [Hervol, David] NASA, Glenn Res Ctr, Analex Corp, Mech Syst Branch,Glenn Engn & Sci Support Org, Cleveland, OH 44135 USA. RP Birchenoughl, A (reprint author), NASA, Glenn Res Ctr, Power Syst Dev Branch, Power & Avion Div, Cleveland, OH 44135 USA. EM David.S.Hervol@nasa.gov NR 4 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 593 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900069 ER PT S AU Geng, SM Mason, LS Dyson, RW Penswick, LB AF Geng, Steven M. Mason, Lee S. Dyson, Rodger W. Penswick, L. Barry BE ElGenk, MS TI Overview of multi-kilowatt free-piston Stirling power conversion research at GRC SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE Stirling power convertors; Stirling engines; Stirling cycle; linear alternators AB As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available I kW class free-piston Stirling convertors and a pair of commercially available pressure wave generators (which will be plumbed together to create a high power Stirling linear alternator test rig) have been procured for in-house testing at Glenn Research Center. Delivery of both the Stirling convertors and the linear alternator test rig is expected by October, 2007. The 1 kW class free-piston Stirling convertors will be tested at GRC to map and verify performance. The convertors will later be modified to operate with a NaK liquid metal pumped loop for thermal energy input. The high power linear alternator test rig will be used to map and verify high power Stirling linear alternator performance and to develop power management and distribution (PMAD) methods and techniques. This paper provides an overview of the multi-kilowatt free-piston Stirling power conversion work being performed at GRC. C1 [Geng, Steven M.; Mason, Lee S.; Dyson, Rodger W.] NASA, Glenn Res Ctr, Thermal Energy Convers Branch, 21000 Brookpk Rd, Cleveland, OH 44135 USA. [Penswick, L. Barry] SEST Inc, Middlebury, OH 44130 USA. RP Geng, SM (reprint author), NASA, Glenn Res Ctr, Thermal Energy Convers Branch, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Steven.M.Geng@nasa.gov NR 10 TC 0 Z9 0 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 617 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900072 ER PT S AU Ravi, V Firdosy, S Caillat, T Lerch, B Calamino, A Pawlik, R Nathal, M Sechrist, A Buchhalter, J Nutt, S AF Ravi, V. Firdosy, S. Caillat, T. Lerch, B. Calamino, A. Pawlik, R. Nathal, M. Sechrist, A. Buchhalter, J. Nutt, S. BE ElGenk, MS TI Mechanical properties of thermoelectric skutterudites SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE thermoelectric materials; power generation; mechanical properties AB A comprehensive approach to determine the mechanical properties of advanced thermoelectric materials is described. The focus of this paper is the mechanical characterization of skutterudites, i.e., LTN-SKD (n-type doped CoSb3) and LTP-SKD (p-type CeFe3-xRuxSb3). Properties such as the elastic modulii, flexural strengths and fracture toughness, are reported and discussed. A summary table of the key mechanical properties is provided. C1 [Ravi, V.; Firdosy, S.; Caillat, T.] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. [Ravi, V.] Calif State Polytech Univ Pomona, Pomona, CA 91768 USA. [Lerch, B.; Calamino, A.; Pawlik, R.; Nathal, M.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Sechrist, A.; Buchhalter, J.; Nutt, S.] Univ Southern Calif, Los Angeles, CA 90089 USA. RP Ravi, V (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Vilupanur.A.Ravi@jpl.nasa.gov NR 6 TC 17 Z9 17 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 656 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900076 ER PT S AU Mitchell, JD Cryan, SP Baker, K Martin, T Goode, R Key, KW Manning, T Chien, CH AF Mitchell, Jennifer D. Cryan, Scott P. Baker, Kenneth Martin, Toby Goode, Robert Key, Kevin W. Manning, Thomas Chien, Chiun-Hong BE ElGenk, MS TI Integrated docking simulation and testing with the Johnson Space Center Six-Degree-of-Freedom dynamic test system SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE navigation; testing; relative navigation sensors; hardware-in-the-loop; simulation; rendezvous; docking AB The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as Automated Rendezvous and Docking, AR&D). The crewed versions may also perform AR&D, possibly with a different level of automation and/or autonomy, and must also provide the crew with relative navigation. information for manual piloting. The capabilities of the Rendezvous, Proximity Operations and Docking (RPOD) sensors are critical to the success of the Constellation Program; this is carried as one of the CEV Project top risks. The Exploration Technology Development Program (ETDP) AR&D Sensor Technology Project seeks to reduce this risk by increasing technology maturation of selected relative navigation sensor technologies through testing and simulation. One of the project activities is a series of "pathfinder" testing and simulation activities to integrate relative navigation. sensors with the Johnson Space Center Six-Degree-of-Freedom Test System (SDTS). The SDTS will be the primary testing location for the Orion spacecraft's Low Impact Docking System (LIDS). Project team members have integrated the Orion GN&C simulation with the SDTS computer system so that real-time closed loop testing can be performed with relative navigation sensors and the docking system in the loop during docking and undocking scenarios. Two relative navigation sensors are being used as part of a "pathfinder" activity in preparation for future testing with the actual Orion sensors. This paper describes the test configuration and test results. C1 [Mitchell, Jennifer D.; Cryan, Scott P.; Baker, Kenneth; Martin, Toby; Goode, Robert] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. [Key, Kevin W.; Manning, Thomas] L3 Commun Titan Grp, Houston, TX 77058 USA. [Chien, Chiun-Hong] GeoControl Syst Inc, Houston 77087, TX USA. RP Mitchell, JD (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 1 TC 3 Z9 3 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 709 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900082 ER PT S AU Howard, RT Heaton, AF Pison, RM Carrington, CL Lee, JE Bryan, TC Robertson, BA Spencer, SH Johnson, JE AF Howard, Richard T. Heaton, Andrew F. Pison, Robin M. Carrington, Connie L. Lee, James E. Bryan, Tbomas C. Robertson, Bryan A. Spencer, Susan H. Johnson, Jimmie E. BE ElGenk, MS TI The Advanced Video Guidance Sensor: Orbital express and the next generation SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE sensors; docking; proximity operations; relative navigation; rendezvous; video AB The Orbital Express (OE) mission performed the first autonomous rendezvous and docking in the history of the United States on May 5-6, 2007 with the Advanced Video Guidance Sensor (AVGS) acting as one of the primary docking sensors. Since that event, the OE spacecraft performed four more rendezvous and docking maneuvers, each time using the AVGS as one of the docking sensors. The Marshall Space Flight Center's (MSFC's) AVGS is a near-field proximity operations sensor that was integrated into the Autonomous Rendezvous and Capture Sensor System (ARCSS) on OE. The ARCSS provided the relative state knowledge to allow the OE spacecraft to rendezvous and dock. The AVGS is a mature sensor technology designed to support Automated Rendezvous and Docking (AR&D) operations. It is a video-based laser-illuminated sensor that can determine the relative position and attitude between itself and its target. Due to parts obsolescence, the AVGS that was flown on OE can no longer be manufactured. MSFC has been working on the next generation of AVGS for application to future Constellation missions. This paper provides an overview of the performance of the AVGS on Orbital Express and discusses the work on the Next Generation AVGS (NGAVGS). C1 [Howard, Richard T.; Carrington, Connie L.; Bryan, Tbomas C.] NASA, George C Marshall Space Flight Ctr, Avion Syst Test Branch EV21, Huntsville, AL 35812 USA. RP Howard, RT (reprint author), NASA, George C Marshall Space Flight Ctr, Avion Syst Test Branch EV21, Huntsville, AL 35812 USA. NR 4 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 717 EP 724 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900083 ER PT S AU Howard, RT Carrington, CK AF Howard, Richard T. Carrington, Connie K. BE ElGenk, MS TI Multi-sensor testing for automated rendezvous and docking SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE sensors; docking; proximity operations; simulation; testing; sensor fusion AB During the past two years, many sensors have been tested in an open-loop fashion in the Marshall Space Flight Center (MSFC) Flight Robotics Laboratory (FRL) to both determine their suitability for use in Automated Rendezvous and Docking (AR&D) systems and to ensure the test facility is prepared for future multi-sensor testing. The primary focus of this work was in support of the CEV AR&D system, because the AR&D sensor technology area was identified as one of the top risks in the program. In 2006, four different sensors were tested individually or in a pair in the MSFC FRL. In 2007, four sensors, two each of two different types, were tested simultaneously. In each set of tests, the target was moved through a series of pre-planned trajectories while the sensor tracked it. In addition, a laser tracker "truth" sensor also measured the target motion. The tests demonstrated the functionality of testing four sensors simultaneously as well as the capabilities (both good and bad) of all of the different sensors tested. This paper outlines the test setup and conditions, briefly describes the facility, surnmarizes the earlier results of the individual sensor tests, and describes in some detail the results of the four-sensor testing. Post-test analysis includes data fusion by minimum variance estimation and sequential Kalman filtering. This Sensor Technology Project work was funded by NASA's Exploration Technology Development Program. C1 [Howard, Richard T.; Carrington, Connie K.] NASA, George C Marshall Space Flight Ctr, Avion Syst Test Branch Ev21, Huntsville, AL 35812 USA. RP Howard, RT (reprint author), NASA, George C Marshall Space Flight Ctr, Avion Syst Test Branch Ev21, Huntsville, AL 35812 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 725 EP 732 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900084 ER PT S AU Canavan, ER Boyle, RF Mustafi, S AF Canavan, E. R. Boyle, R. F. Mustafi, S. BE ElGenk, MS TI Active costorage of cryogenic propellants for exploration SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boening Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshal Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE lunar exploration; cryogenic propellant storage; liquid hydrogen; liquid oxygen AB Long-term storage of cryogenic propellants is a critical requirement for NASA's effort to return to the moon. Liquid hydrogen and liquid oxygen provide the highest specific impulse of any practical chemical propulsion system, and thus provides the greatest payload mass per unit of launch mass. Future manned missions will require vehicles with the flexibility to remain in orbit for months, necessitating long-term storage of these cryogenic liquids. For decades cryogenic scientific satellites have used cryogens to cool instruments. In many cases, the lifetime of the primary cryogen tank has been extended by intercepting much of the heat incident on the tank at an intermediate-temperature shield cooled either by a second cryogen tank or a mechanical cryocooler. For an LH2/LO2 propellant system, a combination of these ideas can be used, in which the shield around the LO2 tank is attached to, and at the same temperature as, the LO2 tank, but is actively cooled so as to remove all heat impinging on the tank and shield. This configuration eliminates liquid oxygen boil-off and cuts the liquid hydrogen boil-off to a small fraction of the unshielded rate. This paper studies the concept of active costorage as a means of long-term cryogenic propellant storage. The paper describes the design impact of an active costorage system for the Crew Exploration Vehicle (CEV). This paper also compares the spacecraft level impact of the active costorage concept with a passive storage option in relation to two different scales of spacecraft that will be used for the lunar exploration effort, the CEV and the Earth Departure Stage (EDS). Spacecraft level studies are performed to investigate the impact of scaling of the costorage technologies for the different components of the Lunar Architecture and for different mission durations. C1 [Canavan, E. R.; Boyle, R. F.; Mustafi, S.] NASA, Goddard Space Flight Ctr, Cryogen & Fluid Branch, Greenbelt, MD 20771 USA. RP Canavan, ER (reprint author), NASA, Goddard Space Flight Ctr, Cryogen & Fluid Branch, Greenbelt, MD 20771 USA. NR 11 TC 0 Z9 1 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 733 EP 740 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900085 ER PT S AU Kortenkamp, D Tzygon, M Lawler, D Schreckenghost, D Bonasso, RP Wang, L Kennedy, K AF Kortenkamp, David Tzygon, Michel Lawler, Dennis Schreckenghost, Debra Bonasso, R. Peter Wang, Lui Kennedy, Kriss BE ElGenk, MS TI A testbed for evaluating lunar habitat autonomy architectures SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE lunar outpost; simulations; automation AB A lunar outpost will involve a habitat with an integrated set of hardware and software that will maintain a safe environment for human activities. There is a desire for a paradigm shift whereby crew will be the primary mission operators, not ground controllers. There will also be significant periods when the outpost is uncrewed. This will require that significant automation software be resident in the habitat to maintain all system functions and respond to faults. JSC is developing a testbed to allow for early testing and evaluation of different autonomy architectures. This will allow evaluation of different software configurations in order to: 1) understand different operational concepts; 2) assess the impact of failures and perturbations on the system; and 3) mitigate software and hardware integration risks. The testbed will provide an environment in which habitat hardware simulations can interact with autonomous control software. Faults can be injected into the simulations and different mission scenarios can be scripted. The testbed allows for logging, replaying and re-initializing mission scenarios. An initial testbed configuration has been developed by combining an existing life support simulation and an existing simulation of the space station power distribution system. Results from this initial configuration will be presented along with suggested requirements and designs for the incremental development of a more sophisticated lunar habitat testbed. C1 [Kortenkamp, David; Schreckenghost, Debra; Bonasso, R. Peter] TRACLabs Inc, Houston, TX 77058 USA. [Tzygon, Michel] Tietronix Inc, Houston, TX 77058 USA. [Lawler, Dennis; Wang, Lui; Kennedy, Kriss] NASA, Johnson Space Ctr, Houston, TX 77058 USA. RP Kortenkamp, D (reprint author), TRACLabs Inc, Houston, TX 77058 USA. EM korten@Dtraclabs.com NR 14 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 741 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900086 ER PT S AU Keys, AS Adams, JH Cressler, JD Dartyl, RC Johnson, MA Patrick, MC AF Keys, Andrew S. Adams, James H. Cressler, John D. Dartyl, Ronald C. Johnson, Michael A. Patrick, Marshall C. BE ElGenk, MS TI High-performance, Radiation-Hardened Electronics for Space and Lunar Environments SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE radiation-hardened; extreme environments; low temperature; FPGA; MEMS; high performance processors; reconfigurable computers; SiGe electronics AB The Radiation Hardened Electronics for Space Environments (RHESE) project develops advanced technologies needed for high performance electronic devices that will be capable of operating within the demanding radiation and thermal extremes of the space, lunar, and Martian environment. The technologies developed under this project enhance and enable avionics within multiple mission elements of NASA's Vision for Space Exploration, including the Constellation program's Orion Crew Exploration Vehicle, the Lunar Lander project, Lunar Outpost elements, and Extra Vehicular Activity (EVA) elements. This paper provides an overview of the RHESE project and its multiple task tasks, their technical approaches, and their targeted benefits as applied to NASA missions. C1 [Keys, Andrew S.; Adams, James H.; Dartyl, Ronald C.; Patrick, Marshall C.] NASA, Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. [Johnson, Michael A.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Keys, AS (reprint author), NASA, Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 3 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 749 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900087 ER PT S AU Schreckenghost, D Fong, T Milam, T AF Schreckenghost, Debra Fong, Terrence Milam, Tod BE ElGenk, MS TI Human supervision of robotic site surveys SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE human-robot interaction; super-vision of autonomous robots; agent-based systems AB Ground operators will interact remotely with robots on the lunar surface to support site preparation and survey. Astronauts will interact with robots to support outpost buildup and maintenance, as well as mission operations. One mode of interaction required for such operations is the ability to supervise robots performing routine autonomous tasks. Supervision of autonomous robotic activities requires monitoring the robot's performance of tasks with minimal human effort. This includes understanding its progress on tasks, awareness when important milestones are achieved or problems impede tasks, and g, situations after the fact by relating task events to recorded data. We are developing a software framework to reconstructing support such interaction among distributed human teams and robots. We are evaluating our framework for human supervision of mobile robots performing routine site survey operations. We are prototyping a system that (1) monitors data from the K10 robot performing surveys to determine the depth of permafrost at the Haughton Crater on Devon Island, (2) computes performance measures about how well the survey is going, (3) builds summaries of these performance measures, and (4) notifies to appropriate personnel when milestones are achieved or performance indicates a problem. We will evaluate our prototype using data collected during Operational Readiness Tests for the Haughton Crater field test to be conducted in July 2007. In this paper we describe our approach for human supervision of robotic activities and report the results of our evaluation with the K10 robot. C1 [Schreckenghost, Debra] TRACLabs, 1012 Hercules, Houston, TX 77058 USA. [Fong, Terrence] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Milam, Tod] S&K Aerosp, Houston, TX 77598 USA. RP Schreckenghost, D (reprint author), TRACLabs, 1012 Hercules, Houston, TX 77058 USA. FU NASA SBIR [NNJ07JB3 IC] FX We acknowledge Mark Allan, Matt Deans, Lorenzo Fluckiger, and Hans Utz for their assistance in integrating the software framework with the KIO rover and providing information about the summaries needed for the site survey. This work was funded under NASA SBIR contract #NNJ07JB3 IC. NR 16 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 776 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900090 ER PT S AU Schreckenghost, D Ngo, T Burridge, R Wang, L Izygon, M AF Schreckenghost, Debra Ngo, Tam Burridge, Robert Wang, Lui Izygon, Michel BE ElGenk, MS TI Remote task-level commanding of Centaur over time delay SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE task-level commanding; remote supervision of robots; electronic procedures AB Remote operation of robots on the lunar surface by ground controllers poses unique human-robot interaction challenges due to time delay and constrained bandwidth. One strategy for addressing these challenges is to provide task-level commanding of robots by a ground controller. Decision-support tools are being developed at JSC for remote task-level commanding over time-delay. The approach is to provide ground procedures that guide a controller when executing task-level command sequences and aid awareness of the state of command execution in the robot. This approach is being evaluated using the Centaur robot at JSC. The Centaur Central Commander provides a task-level command interface that executes on the robot side of the delay. Decision support tools have been developed for a human Supervisor in the JSC Cockpit to use when interacting with the Centaur Central Commander. Commands to the Central Commander are defined as instructions in a procedure. Sequences of these instructions are grouped into procedures for the Cockpit Supervisor. When a Super-visor is ready to perform a task, a procedure is loaded into the decision support tool. From this tool, the Supervisor can view command sequences and dispatch individual commands to Centaur. Commands are queued for execution on the robot side of the delay. Reliable command sequences can be dispatched automatically upon approval by the Supervisor. The decision support tool provides the Supervisor with feedback about which commands are waiting for execution and which commands have finished. It also informs the Supervisor when a command fails to have its intended effect. Cockpit procedures are defined using the Procedure Representation Language (PRL) developed at JSC for mission operations. The decision support tool is based on a Procedure Sequencer and multi-agent software developed for human-robot interaction. In this paper the approach for remote task-level commanding of robots is described and the results of the evaluation with the Centaur robot at JSC are discussed. C1 [Schreckenghost, Debra; Burridge, Robert] TRACLabs, 1012 Hercules, Houston, TX 77058 USA. [Ngo, Tam; Wang, Lui] NASA, Johnson Space Ctr, Houston, TX 77058 USA. [Izygon, Michel] Tietronix, Houston, TX 77058 USA. RP Schreckenghost, D (reprint author), TRACLabs, 1012 Hercules, Houston, TX 77058 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 784 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900091 ER PT S AU Doggett, W Dorsey, J Collins, T King, B Mikulas, M AF Doggett, William Dorsey, John Collins, Tim King, Bruce Mikulas, Martin BE ElGenk, MS TI A versatile lifting device for lunar surface payload handling, inspection & regolith transport operations SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE payload handling; outpost; inspection; regolith excavation; crane; lifting; lander unload; automated lunar operations AB Devices for lifting and transporting payloads and material are critical for efficient Earth-based construction operations. Devices with similar functionality will be needed to support lunar-outpost construction, servicing, inspection, regolith excavation, grading and payload placement. Past studies have proposed that only a few carefully selected devices are required for a lunar outpost. One particular set of operations involves lifting and manipulating payloads in the 100 kg to 3,000 kg range, which are too large or massive to be handled by unassisted astronauts. This paper will review historical devices used for payload handling in space and on earth to derive a set of desirable features for a device that can be used on planetary surfaces. Next, an innovative concept for a lifting device is introduced, which includes many of the desirable features. The versatility of the device is discussed, including its application to lander unloading, servicing, inspection, regolith excavation and site preparation. Approximate rules, which can be used to size the device for specific payload mass and reach requirements, are provided. Finally, details of a test-bed implementation of the innovative concept, which will be used to validate the structural design and develop operational procedures, is provided. C1 [Doggett, William; Dorsey, John; Collins, Tim] NASA, Langley Res Ctr, MS-190, Hampton, VA 23681 USA. [King, Bruce] Lockheed Martin, Martin, TN USA. [Mikulas, Martin] Natl Inst Aeronaut, Bethesda, MD 20892 USA. RP Doggett, W (reprint author), NASA, Langley Res Ctr, MS-190, Hampton, VA 23681 USA. EM william.r.doggett@nasa.gov NR 11 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 792 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900092 ER PT S AU Marzwell, N Pogorzelski, RJ Chang, K Little, F AF Marzwell, Neville Pogorzelski, Ronald J. Chang, Kai Little, Frank BE ElGenk, MS TI Technologies for lunar surface power systems power beaming and transfer SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE wireless power transmission; rectenna; frequency allocations ID PHASE-LOCKING; RELATIVISTIC MAGNETRONS; COUPLED OSCILLATORS; ARRAY; SPACE AB Wireless power transmission within a given working area is required or enabling for many NASA Exploration Systems. Fields of application include robotics, habitats, autonomous rendezvous and docking, life support, EVA, and many others. In robotics applications, for example, the robots must move in the working area without being hampered by power cables and, meanwhile, obtain a continuous and constant power from a power transmitter. The development of modem technology for transmitting electric power over free space has been studied for several decades, but its use in a system has been mainly limited to low power, 1-2 Vdc output voltage at a transmission distance of few meters for which relatively less than 0.5 mW/cm2 is required (e.g., Radio frequency identification RFID), Most of the rectenna conversion efficiency research to date has concentrated in low GHz frequency range of 2.45 to 10 GHz, with some work at 35 GHz. However, for space application, atmospheric adsorbtion is irrelevant and higher frequency systems with smaller transmit and receive apertures may be appropriate. For high power, most of the work on rectennas has concentrated on optimizing the conversion efficiency of the microwave rectifier element; the highest power demonstrated was 35 kW of power over a distance of 1.5km. The objective of this paper is to establish the manner in which a very large number of very low power microwave devices can be synchronized to provide a beam of microwaves that can be used to efficiently and safely transport a significant amount of power to a remote location where it can be converted to dc (or ac) power by a "rectenna." The proposed system is based on spatial power combining of the outputs of a large number of devices synchronized by mutual injection locking. We have demonstrated at JPL that such power could be achieved by combining 25 sources in a configuration that allows for convenient steering of the resulting beam of microwaves. Retrodirective beam steering for microwave power transmission (the ability to accurately track a moving receiver) has been demonstrated at Texas A&M. It is proposed that the next step in development of this concept is a modest scale up from 25 elements to 435 followed by a further scale up using such 435 element arrays as subarrays for a still larger retrodirective system. Ultimately, transmit antenna sizes on the order of 100 meters are envisioned permitting transfer levels on the order of 30 kW to aerial vehicles up to 20 km. C1 [Marzwell, Neville; Pogorzelski, Ronald J.] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. [Chang, Kai; Little, Frank] Texas A&M Univ, College Stn, TX 77843 USA. RP Marzwell, N (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Neville.I.Marzmell@ipl.nasa.gov NR 38 TC 0 Z9 0 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 809 EP + PG 3 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900093 ER PT S AU Feather, MS Uckun, S Hicks, KA AF Feather, Martin S. Uckun, Serdar Hicks, Kenneth A. BE ElGenk, MS TI Technology maturation of Integrated System Health Management SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE ISHM; technology maturation; risk AB Despite two decades of significant investments in R&D of Integrated System Health Management (ISHM), mission-critical applications of it in aerospace are few and far between. ISHM is subject to the general difficulty of transitioning technologies out of R&D labs and into practical applications. New and unproven methods such as ISHM introduce multiple mission risks (technology, schedule, cost), and may require a transition to unconventional and as-yet-unproven operations concepts in order to be effective. Laboratory and flight demonstrations are necessary but insufficient to adequately reduce those risks. What is needed is a solid business case before a new technology can be considered for fleetwide deployment. To address these problems, we recently applied a technology maturation assessment process developed at NASA's Jet Propulsion Laboratory to study the challenges of ISHM technology maturation. This application resulted in identification of the technologies (and technology maturation activities) that would result in the greatest risk reduction per investment dollar. Our approach and its results are described herein. C1 [Feather, Martin S.; Hicks, Kenneth A.] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. [Uckun, Serdar] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Feather, MS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM uckun@maiLarc.nasa.gov FU NASA Code Q (now OSMA); NASA ESMD FX The research described in this paper was carried out at NASA Ames Research Center and at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. In addition to the authors of this paper, the following individuals' contributions were key to the success of the study reported herein: from NASA Ames, Scott Christa, Arm Patterson-Hine, Dougal Machse, Robert Mah, Dwight Sanderfer and Mark Schwabacher; from JPL, Ryan Mackey and Arthur Murphy. We also thank Steve Comford (JPL), who invented the methodology that underpins the TIMA process and gave us valuable guidance in this study. Steve Comford and Martin Feather's work at JPL to develop the methodology and the custom software that supports it has been funded initially by NASA Code Q (now OSMA) and subsequently by NASA ESMD. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 827 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900095 ER PT S AU Richmond, RC Kusiak, A Ramachandran, N AF Richmond, R. C. Kusiak, A. Ramachandran, N. BE ElGenk, MS TI Risk-assessment for equipment operating on the lunar surface SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE lunar dust; SEM image analysis; mechanical testing; wear; risk-assessment ID DATA-MINING APPROACH; DESIGN AB Particle-size distribution of lunar dust simulant is evaluated using scanning electron spectroscopy in order to consider approaches to evaluating risk to individual mechanical components operating on the lunar surface. Assessing component risk and risk-mitigation during actual operations will require noninvasive continuous data gathering on numerous parameters. Those data sets would best be evaluated using data-mining algorithms to assess risk, and recovery from risk, of individual mechanical components in real-time. C1 [Richmond, R. C.; Ramachandran, N.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Kusiak, A.] Univ Iowa, Dept Mech & Ind Engn, Iowa City, IA 52242 USA. RP Richmond, RC (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. FU Lunar Dust Assessment Project of the Mechanical Systems SPRT funded through the NASA Engineering and Safety Center FX The Lunar Dust Assessment Project of the Mechanical Systems SPRT funded through the NASA Engineering and Safety Center is acknowledged for partial support of this work. NR 16 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 888 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900101 ER PT S AU Ray, CS Reis, ST Sen, S AF Ray, Chandra S. Reis, Signo T. Sen, Subhayu BE ElGenk, MS TI Characterization and glass formation of JSC-1 Lunar and Martian soil simulants SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE Lunar and Martian soils simulants; glass formation; XRD; DTA and Mossbauer ID MOSSBAUER AB The space exploration mission of NASA requires human and robotic presence for long duration beyond the low earth orbit (LEO), especially on Moon and Mars. Developing a human habitat or colony on these planets would require a diverse range of materials, whose applications would range from structural foundations, (human) life support, (electric) power generation to components for scientific instrumentations. A reasonable and cost-effective approach for fabricating the materials needed for establishing a self-sufficient human outpost would be to primarily use local (in situ) resources on these planets. Since ancient times, glass and ceramics have been playing a vital role on human civilization. A long term project on studying the feasibility of developing glass and ceramic materials has been undertaken using Lunar and Martian soil simulants (JSC-1) as developed by Johnson Space Center. The first step in this on-going project requires developing a data base on results that fully characterize the simulants to be used for further investigations. The present paper reports characterization data of both JSC-1 Lunar and JSC Mars-1 simulants obtained up to this time via x-ray diffraction analysis, scanning electron microscopy, thermal analysis (DTA, TGA) and chemical analysis. The critical cooling rate for glass formation for the melts of the simulants was also measured in order to quantitatively assess the glass forming tendency of these melts. The importance of the glasses and ceramics developed using in-situ resources for constructing human habitats on Moon or Mars is discussed. C1 [Ray, Chandra S.; Reis, Signo T.] Univ Missouri, Grad Ctr Mat Res, Rolla, MO 65409 USA. [Sen, Subhayu] NASA, Marshall Space Flight Ctr, BAE Syst, Huntsville, AL 35812 USA. RP Ray, CS (reprint author), Univ Missouri, Grad Ctr Mat Res, Rolla, MO 65409 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 908 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900103 ER PT S AU Detweiler, MK Curreri, PA AF Detweiler, Michael K. Curreri, Peter A. BE ElGenk, MS TI The space homestead and creation of real estate and industry beyond Earth SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE space resource utilization; space settlement; space habitats; space solar power AB During the 1970s large habitats were proposed by G. K. O'Neill and studied by NASA that could house 10,000 to 4 million people in Earth / Moon space. These people would be employed in building space solar satellites and more habitats for new settlers. Such a program, the NASA studies concluded, could reach financial break even in 38 years with peak Apollo level expenditures. It was suggested in a previous paper that human settlement of space could begin not by building city size structures but with a minimum technology habitat that could provide subsistence for a more minimal number of people and be capable of producing new habitats with extraterrestrial materials and energy. These habitats would be mostly independent from Earth. The approach could provide a quicker return on investment and lower start-up costs, and could be of a scale that could be developed and tested within the planned NASA transportation and lunar base architecture. This paper examines the population growth kinetics of humans in space, and the development of space solar power industry using small bolo shaped habitats in comparison to using larger habitat designs as considered in the 1970s. C1 [Detweiler, Michael K.] Bates Coll 244, Lewiston, ME 04240 USA. [Curreri, Peter A.] NASA, Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Detweiler, MK (reprint author), Bates Coll 244, Lewiston, ME 04240 USA. EM mkdetweiler@gmail.com; peter.a.curreri@nasa.gov NR 14 TC 1 Z9 1 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 925 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900105 ER PT S AU Abbas, MM Tankosic, D Spann, JF Dube, MJ Gaskin, JA AF Abbas, Mian M. Tankosic, Dragana Spann, James F. Dube, Michael J. Gaskin, Jessica A. BE ElGenk, MS TI Measurements of charging of Apollo 17 lunar dust grains by electron impact SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE lunar dust charging; electron impact charging of dust ID PARTICLES; RADIATION; EMISSION; ANALOGS AB It is well known since the Apollo missions that the lunar surface is covered with a thick layer of micron size dust grains with unusually high adhesive characteristics. The dust grains levitated and transported on the lunar surface are believed to have a hazardous impact on the robotic and human missions to the Moon. The observed dust phenomena are attributed to the lunar dust being charged positively during the day by UV photoelectric emissions, and negatively during the night by the solar wind electrons. The current dust charging and the levitation models, however, do not fully explain the observed phenomena, with the uncertainty of dust charging processes and the equilibrium potentials of the individual dust grains. It is well recognized that the charging properties of individual dust grains are substantially different from those determined from measurements made on bulk materials that are currently available. An experimental facility has been developed in the Dusty Plasma Laboratory at MSFC for investigating the charging and optical properties of individual micron/sub-micron size positively or negatively charged dust grains by levitating them in an electrodynamic balance in simulated space environments. In this paper, we present the laboratory measurements on charging of Apollo 17 individual lunar dust grains by a low energy electron beam. The charging rates and the equilibrium potentials produced by direct electron impact and by secondary electron emission process are discussed. C1 [Abbas, Mian M.; Spann, James F.; Gaskin, Jessica A.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Tankosic, Dragana] Univ Alabama, Huntsville, AL 35899 USA. [Dube, Michael J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Abbas, MM (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM Mian.M.Abbas@nasa.gov FU MSFC-IRAD; NESC-Mechanical Systems Lunar Dust Assessment; NASA-Johnson Space Center FX The work reported has been supported the MSFC-IRAD and the NESC-Mechanical Systems Lunar Dust Assessment program. The Apollo lunar dust samples employed in the measurements presented here were kindly provided by NASA-Johnson Space Center. Helpful discussions with Drs. Dermis Gallagher and Robert Sheldon and are gratefully acknowledged. NR 20 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 942 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900107 ER PT S AU Rickman, D Street, KW AF Rickman, Doug Street, Kenneth W. BE ElGenk, MS TI Some expected mechanical characteristics of lunar dust: A geological view SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE lunar regolith; mineralogy; engineering materials; abrasion AB The engineering properties of the lunar regolith reflect aspects of the original parent rock and the consequences of hypervelocity meteor bombardment. Compared to the Earth the geologic nature of the lunar regolith is quite distinct. On scales relevant to machinery, heterogeneity with respect to size and composition is much higher. But the total range in composition is much more restricted. Both facts have implications for predictions of properties, such as abrasion, which will be required by design engineers for constructing equipment for lunar use. Abrasion is related to hardness and hardness is a commonly measured property for both minerals and engineering materials. Although different hardness scales are routinely employed for minerals and engineering materials, a significant amount of literature is available relating the two. In this paper we discuss how to relate hardness to abrasion for the design of lunar equipment. We also indicate how abundant the various mineral phases are and typical size distributions for lunar regolith. C1 [Rickman, Doug] NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. [Street, Kenneth W.] NASA Glenn Res Ctr, Tribol & Surface Sci, Cleveland, OH 44135 USA. RP Rickman, D (reprint author), NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. EM doug.rickman@nasa.gov OI Rickman, Doug/0000-0003-3409-2882 NR 16 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 949 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900108 ER PT S AU Cole, JW Silvera, IF Foote, JP AF Cole, John W. Silvera, Isaac F. Foote, John P. BE ElGenk, MS TI Conceptual launch vehicles using metallic hydrogen propellant SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE metallic hydrogen; propulsion; launch vehicle concepts; energetic materials; HEDM; rocket engines ID SOLID HYDROGEN; GPA AB Solid molecular hydrogen is predicted to transform into an atomic solid with metallic properties under pressures >4.5 Mbar. Atomic metallic hydrogen is predicted to be metastable, limited by some critical temperature and pressure, and to store very large amounts of energy. Experiments may soon determine the critical temperature, critical pressure, and specific energy availability. It is useful to consider the feasibility of using metastable atomic hydrogen as a rocket propellant. If one assumes that metallic hydrogen is stable at usable temperatures and pressures, and that it can be affordably produced, handled, and stored, then it may be a useful rocket propellant. Assuming further that the available specific energy can be determined from the recombination of the atoms into molecules (216 MJ/kg), then conceptual engines and launch vehicle concepts can be developed. Under these assumptions, metallic hydrogen would be a revolutionary new rocket fuel with a theoretical specific impulse of 1700 s at a chamber pressure of 100 atm. A practical problem that arises is that rocket chamber temperatures may be too high for the use of this pure fuel. This paper examines an engine concept that uses liquid hydrogen or water as a diluent coolant for the metallic hydrogen to reduce the chamber temperature to usable values. Several launch vehicles are then conceptually developed. Results indicate that if metallic hydrogen is experimentally found to have the properties assumed in this analysis, then there are significant benefits. These benefits become more attractive as the chamber temperatures increase. C1 [Cole, John W.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Foote, John P.] Jacobs ESTS, Huntsville, AL 35812 USA. [Silvera, Isaac F.] Harvard Univ, Cambridge, MA 02138 USA. RP Cole, JW (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM John.W.Cole@nasa.gov NR 15 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 977 EP + PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900111 ER PT S AU Tweed, J Walker, SA Wilson, JW Tripathi, RK AF Tweed, John Walker, Steven A. Wilson, John W. Tripathi, Ram K. BE ElGenk, MS TI Recent progress in the development of a multi-layer Green's function code for ion beam transport SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM STAIF 2008 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2008) CY FEB 10-14, 2008 CL Univ New Mexico, Inst Space & Nucl Power Studies, Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Sandia Natl Labs, NASA Marshall Space Flight Ctr, Los Alamos Natl Lab, US Dept Energy HO Univ New Mexico, Inst Space & Nucl Power Studies DE ion beam transport; radiation shielding; multi-layer Green's function ID HZETRN CODE AB To meet the challenge of future deep space programs, an accurate and efficient engineering code for analyzing the shielding requirements against high-energy galactic heavy radiation is needed. To address this need, a new Green's function code capable of simulating high charge and energy ions with either laboratory or space boundary conditions is currently under development. The computational model consists of combinations of physical perturbation expansions based on the scales of atomic interaction, multiple scattering, and nuclear reactive processes with use of the Neumann-asymptotic expansions with non-perturbative corrections. The code contains energy loss due to straggling, nuclear attenuation, nuclear fragmentation with energy dispersion and downshifts. Previous reports show that the new code accurately models the transport of ion beams through a single slab of material. Current research efforts are focused on enabling the code to handle multiple layers of material and the present paper reports on progress made towards that end. C1 [Tweed, John; Walker, Steven A.] Old Dominion Univ, Dept Math & Stat, Norfolk, VA 23529 USA. [Wilson, John W.; Tripathi, Ram K.] NASA Langley Res Ctr, Hampton, VA 23681 USA. RP Tweed, J (reprint author), Old Dominion Univ, Dept Math & Stat, Norfolk, VA 23529 USA. EM jtweed@odu.edu NR 15 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0486-1 J9 AIP CONF PROC PY 2008 VL 969 BP 993 EP + PG 3 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BHL11 UT WOS:000253969900113 ER PT S AU Goldsmith, PF Bradford, M Dragovan, M Paine, C Satter, C Langer, B Yorke, H Huffenberger, K Benford, D Lester, D AF Goldsmith, Paul F. Bradford, Matt Dragovan, Mark Paine, Chris Satter, Celeste Langer, Bill Yorke, Harold Huffenberger, Kevin Benford, Dominic Lester, Dan BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI CALISTO: The cryogenic aperture large infrared space telescope observatory - art. no. 701020 SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE submillimeter/far-infrared space observatory; astronomical background limited sensitivity; star formation; cooling lines; molecular hydrogen; debris disks; Trans-Neptunian Objects ID MOLECULAR-HYDROGEN; 1ST STARS; GALAXY; SYSTEM; H-2 AB CALISTO, the Cryogenic Aperture Large Infrared Space Telescope Observatory, will enable extraordinarily high sensitivity far-infrared continuum and moderate (R similar to 1000) resolution spectroscopic observations at wavelengths from similar to 30 mu m to similar to 300 mu m - the wavelengths between those accessible by JWST and future ground based facilities. CALISTO's observations will provide vital information about a wide range of important astronomical questions including (1) the first stars and initial heavy element production in the universe; (2) structures in the universe traced by H-2 emission; (3) the evolution of galaxies and the star formation within them (4) the formation of planetary systems through observations of protostellar and debris disks; (5) the outermost portions of our solar system through observations of Trans-Neptunian Objects (TNOs) and the Oort cloud. With optics cooled to below 5 K, the photon fluctuations from the astronomical background (Zodiacal, Galactic, and extragalactic) exceed those from the telescope. Detectors with a noise equivalent power below that set by the background will make possible astronomical-background-limited sensitivity through the submillimeter/far-infrared region. CALISTO builds on studies for the SAFIR (Single Aperture Far Infrared) telescope mission, employing a 4m x 6m off-axis Gregorian telescope which has a simple deployment using an Atlas V launch vehicle. The unblocked telescope with a cold stop has minimal sidelobes and scattering. The clean beam will allow astronomical background limited observations over a large fraction of the sky, which is what is required to achieve CALISTO's exciting science goals. The maximum angular resolution varies from 1.2" at 30 gm to 12" at 300 mu m. The 5 sigma 1 hr detectable fluxes are Delta S(d upsilon/upsilon) = 1.0) = 2.2 x 10(-20) Wm(-2), and Delta S(d upsilon/upsilon) = 0.001) = 6.2 x 10(-22) Wm(-2). The 8 beams per source confusion limit at 70 mu m is estimated to be 5 mu Jy. We discuss CALISTO optics, performance, instrument complement, and mission design, and give an overview of key science goals and required technology development to enable this promising far IR/submm mission. C1 [Goldsmith, Paul F.; Bradford, Matt; Dragovan, Mark; Paine, Chris; Satter, Celeste; Langer, Bill; Yorke, Harold; Huffenberger, Kevin] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Goldsmith, PF (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Benford, Dominic/D-4760-2012 OI Benford, Dominic/0000-0002-9884-4206 NR 19 TC 5 Z9 5 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP 1020 EP 1020 DI 10.1117/12.788412 PN 1-2 PG 16 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800061 ER PT S AU Stahl, HP AF Stahl, H. Philip BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Design study of 8 meter monolithic mirror UV/optical space telescope - art. no. 701022 SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE large space telescopes; UV/optical space telescopes; Ares V launch vehicle; astronomy AB The planned Ares V launch vehicle with its 10 meter fairing shroud and 55,000 kg capacity to the Sun Earth L2 point enables entirely new classes of space telescopes. NASA MSFC has conducted a preliminary study that demonstrates the feasibility of launching a 6 to 8 meter class monolithic primary mirror telescope to Sun-Earth L2 using an Ares V. Specific technical areas studied included optical design; structural design/analysis including primary mirror support structure, sun shade and secondary mirror support structure; thermal analysis; launch vehicle performance and trajectory; spacecraft including structure, propulsion, GN&C, avionics, power systems and reaction wheels; operations & servicing; mass and power budgets; and system cost. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Stahl, HP (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 5 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP 1022 EP 1022 DI 10.1117/12.787985 PN 1-2 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800063 ER PT S AU Leisawitz, D Hyde, TT Rinehart, SA Weiss, M AF Leisawitz, David Hyde, T. Tupper Rinehart, Stephen A. Weiss, Michael BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI The Space Infrared Interferometric Telescope (SPIRIT): the mission design solution space and the art of the possible - art. no. 701028 SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE infrared; submillimeter; interferometry; infrared detectors; cryogenic optics; Origins Probe ID KINETIC-INDUCTANCE DETECTORS AB Although the Space Infrared Interferometric Telescope (SPIRIT) was studied as a candidate NASA Origins Probe mission, the real world presents a broader set of options, pressures, and constraints. Fundamentally, SPIRIT is a far-IR observatory for high-resolution imaging and spectroscopy designed to address a variety of compelling scientific questions. How do planetary systems form from protostellar disks, dousing some planets in water while leaving others dry? Where do planets form, and why are some ice giants while others are rocky? How did high-redshift galaxies form and merge to form the present-day population of galaxies? This paper takes a pragmatic look at the mission design solution space for SPIRIT, presents Probe-class and facility-class mission scenarios, and describes optional design changes. The costs and benefits of various mission design alternatives are roughly evaluated, giving a basis for further study and to serve as guidance to policy makers. C1 [Leisawitz, David; Hyde, T. Tupper; Rinehart, Stephen A.; Weiss, Michael] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Leisawitz, D (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP 1028 EP 1028 DI 10.1117/12.789952 PN 1-2 PG 11 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800069 ER PT S AU Trauger, J Stapelfeldt, K Traub, W Henry, C Krist, J Mawet, D Moody, D Park, P Pueyo, L Serabyn, E Shaklan, S Guyon, O Kasdin, J Spergel, D Vanderbei, R Belikov, R Marcy, G Brown, RA Schneider, J Woodgate, B Matthews, G Egerman, R Polidan, R Lillie, C Ealey, M Price, T AF Trauger, John Stapelfeldt, Karl Traub, Wesley Henry, Curt Krist, John Mawet, Dimitri Moody, Dwight Park, Peggy Pueyo, Laurent Serabyn, Eugene Shaklan, Stuart Guyon, Olivier Kasdin, Jeremy Spergel, David Vanderbei, Robert Belikov, Ruslan Marcy, Geoff Brown, Robert A. Schneider, Jean Woodgate, Bruce Matthews, Gary Egerman, Robert Polidan, Ronald Lillie, Chuck Ealey, Mark Price, Thomas BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI ACCESS - a NASA mission concept study of an Actively-Corrected Coronagraph for Exoplanet System Studies - art. no. 701029 SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE coronagraphs; exoplanets; space astronomy; active optics ID PHASE-MASK CORONAGRAPH; EXTRASOLAR PLANET; TELESCOPE; PRINCIPLE; IMAGE; SPACE; DISKS AB ACCESS (Actively-Corrected Coronagraph for Exoplanet System Studies) develops the science and engineering case for an investigation of exosolar giant planets, super-earths, exo-earths, and dust/debris fields that would be accessible to a medium-scale NASA mission. The study begins with the observation that coronagraph architectures of all types (other than the external occulter) call for an exceptionally stable telescope and spacecraft, as well as active wavefront correction with one or more deformable mirrors (DMs). During the study, the Lyot, shaped pupil, PIAA, and a number of other coronagraph architectures will all be evaluated on a level playing field that considers science capability (including contrast at the inner working angle (IWA), throughput efficiency, and spectral bandwidth), engineering readiness (including maturity of technology, instrument complexity, and sensitivity to wavefront errors), and mission cost so that a preferred coronagraph architecture can be selected and developed for a medium-class mission. C1 [Trauger, John; Stapelfeldt, Karl; Traub, Wesley; Henry, Curt; Krist, John; Mawet, Dimitri; Moody, Dwight; Park, Peggy; Pueyo, Laurent; Serabyn, Eugene; Shaklan, Stuart] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Trauger, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Stapelfeldt, Karl/D-2721-2012 NR 35 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP 1029 EP 1029 DI 10.1117/12.789119 PN 1-2 PG 11 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800070 ER PT S AU Lou, JZ Redding, D Sigrist, N Basinger, S AF Lou, John Z. Redding, David Sigrist, Norbert Basinger, Scott BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Telescope multi-field wavefront control with a Kalman Filter - art. no. 701043 SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE space telescope; multi-field wavefront control; optical state estimation and correction AB An effective multi-field wavefront control (WFC) approach is demonstrated for an actuated, segmented space telescope using wavefront measurements at the exit pupil, and the optical and computational implications of this approach are discussed. The integration of a Kalman Filter as an optical state estimator into the wavefront control process to further improve the robustness of the optical alignment of the telescope will also be discussed. Through a comparison of WFC performances between on-orbit and ground-test optical system configurations, the connection (and a possible disconnection) between WFC and optical system alignment under these circumstances are analyzed. Our MACOS-based [2] computer simulation results will be presented and discussed. C1 [Lou, John Z.; Redding, David; Sigrist, Norbert; Basinger, Scott] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Lou, JZ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP 1043 EP 1043 DI 10.1117/12.788198 PN 1-2 PG 13 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800117 ER PT S AU Krist, JE Shaklan, SB Levine, MB AF Krist, John E. Shaklan, Stuart B. Levine, Marie B. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Extraction of extrasolar planet spectra from realistically-simulated, wavefront-corrected, coronagraph fields - art. no. 701044 SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE coronagraph; extrasolar planets; Terrestrial Planet Finder AB The observation of an extrasolar planet in reflected light using a coronagraphic telescope requires a several-orders-of-magnitude reduction of scattered light around a star by controlling instrumental wavefront errors with deformable mirrors (DMs). This creates a "dark hole" in the background in which diminished speckles of scattered light are at a level similar to or less than that of a planet. There are a number of methods for detecting the planet in this dark field, including image subtraction from another telescope orientation. However, extracting the spectrum of the planet from such a field may be more difficult because the chromatic variation of the speckles can hide spectral features, and the need to disperse the light on a detector increases noise. To investigate the conditions in which spectral extractions are feasible, a physical optics propagation simulation was created of a band-limited Lyot coronagraphic telescope with realistic phase and amplitude errors on each optic and dual sequential DMs to correct the resulting wavefront errors. The Electric Field Conjugation method was used to set the DMs to create a broadband (25%) dark hole from lambda = 625-878 nm. Simulated planet spectra were then extracted from within this hole using a variety of methods including roll subtraction and spectral filtering. The results of these experiments are presented. C1 [Krist, John E.; Shaklan, Stuart B.; Levine, Marie B.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Krist, JE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP 1044 EP 1044 DI 10.1117/12.789788 PN 1-2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800118 ER PT S AU Lyon, RG Clampin, M Melnick, G Tolls, V Woodruff, R Vasudevan, G AF Lyon, Richard G. Clampin, Mark Melnick, Gary Tolls, Volker Woodruff, Robert Vasudevan, Gopal BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Extrasolar Planetary Imaging Coronagraph (EPIC): Visible nulling coronagraph testbed results - art. no. 701045 SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE planet detection; nulling; coronagraphy; interferometry AB The Extrasolar Planetary Imaging Coronagraph (EPIC) is a NASA Astrophysics Strategic Mission Concept under study for the upcoming Exoplanet Probe. EPIC's mission would be to image and characterize extrasolar giant planets, and potential super-Earths, in orbits with semi-major axes between 2 and 10 AU. EPIC will provide insights into the physical nature of a variety of planets in other solar systems complimenting radial velocity (RV) and astrometric planet searches. It will detect and characterize the atmospheres of planets identified by radial velocity surveys and potentially some transits, determine orbital inclinations and masses, characterize the atmospheres of gas giants around A and F stars, observed the inner spatial structure and colors of inner Spitzer selected debris disks. EPIC would be launched into a heliocentric Earth trailing drift-away orbit, with a 3-year mission lifetime (5 year goal) and will revisit planets at least three times. The starlight suppression approach consists of a visible nulling coronagraph (VNC) that enables high order starlight suppression in broadband light. To demonstrate the VNC approach and advance it's technology readiness the NASA/Goddard Space Flight Center and Lockheed-Martin have developed a laboratory VNC and have demonstrated white light nulling. We will discuss our ongoing VNC work and show the latest results from the VNC testbed. C1 [Lyon, Richard G.; Clampin, Mark] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. RP Lyon, RG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. RI Clampin, mark/D-2738-2012 NR 3 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP 1045 EP 1045 DI 10.1117/12.789700 PN 1-2 PG 7 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800119 ER PT S AU Benford, DJ Lauer, TR Woodruff, RA van Bezooijen, RWH Vasudevan, G AF Benford, Dominic J. Lauer, Tod R. Woodruff, Robert A. van Bezooijen, Roelof W. H. Vasudevan, Gopal BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Precision attitude determination for an infrared space telescope - art. no. 70104A SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE precision pointing; infrared space telescope; attitude determination; attitude control AB We have developed performance simulations for a precision attitude determination system using a focal plane star tracker on an infrared space telescope. The telescope is being designed for the Destiny mission to measure cosmologically distant supernovae as one of the candidate implementations for the Joint Dark Energy Mission. Repeat observations of the supernovae require attitude control at the level of 0.010 arcseconds (0.05 microradians) during integrations and at repeat intervals up to and over a year. While absolute accuracy is not required, the repoint precision is challenging. We have simulated the performance of a focal plane star tracker in a multidimensional parameter space, including pixel size, read noise, and readout rate. Systematic errors such as proper motion, velocity aberration, and parallax can be measured and compensated out. Our prediction is that a relative attitude determination accuracy of 0.001 to 0.002 arcseconds (0.005 to 0.010 microradians) will be achievable. Attitude control will have a jitter of around 0.003 arcseconds and stability/repeatability to around 0.002 arcseconds. C1 [Benford, Dominic J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Benford, DJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012 OI Benford, Dominic/0000-0002-9884-4206 NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP A104 EP A104 DI 10.1117/12.789919 PN 1-2 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800123 ER PT S AU Moustakas, LA Bolton, AJ Booth, JT Bullock, JS Cheng, E Coe, D Fassnacht, CD Gorjian, V Heneghan, C Keeton, CR Kochanek, CS Lawrence, CR Marshall, PJ Metcalf, RB Natarajan, P Nikzad, S Peterson, BM Wambsganss, J AF Moustakas, Leonidas A. Bolton, Adam J. Booth, Jeffrey T. Bullock, James S. Cheng, Edward Coe, Dan Fassnacht, Christopher D. Gorjian, Varoujan Heneghan, Cate Keeton, Charles R. Kochanek, Christopher S. Lawrence, Charles R. Marshall, Philip J. Metcalf, R. Benton Natarajan, Priyamvada Nikzad, Shouleh Peterson, Bradley M. Wambsganss, Joachim CA OMEGA Team BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI The Observatory for Multi-Epoch Gravitational Lens Astrophysics (OMEGA) - art. no. 70101B SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE strong gravitational lensing; time domain; dark matter; expansion history; active galactic nuclei; space telescope; spectroscopy; astronomical survey ID SUBSTRUCTURE AB Dark matter in a universe dominated by a cosmological constant seeds the formation of structure and is the scaffolding for galaxy formation. The nature of dark matter remains one of the fundamental unsolved problems in astrophysics and physics even though it represents 85% of the mass in the universe, and nearly one quarter of its total mass-energy budget. The mass function of dark matter "substructure" on sub-galactic scales may be enormously sensitive to the mass and properties of the dark matter particle. On astrophysical scales, especially at cosmological distances, dark matter substructure may only be detected through its gravitational influence on light from distant varying sources. Specifically, these are largely active galactic nuclei (AGN), which are accreting super-massive black holes in the centers of galaxies, some of the most extreme objects ever found. With enough measurements of the flux from AGN at different wavelengths, and their variability over time, the detailed structure around AGN, and even the mass of the super-massive black hole can be measured. The Observatory for Multi-Epoch Gravitational Lens Astrophysics (OMEGA) is a mission concept for a 1.5-m near-UV through near-IR space observatory that will be dedicated to frequent imaging and spectroscopic monitoring of similar to 100 multiply-imaged active galactic nuclei over the whole sky. Using wavelength-tailored dichroics with extremely high transmittance, efficient imaging in six channels will be done simultaneously during each visit to each target. The separate spectroscopic mode, engaged through a flip-in mirror, uses an image slicer spectrograph. After a period of many visits to all targets, the resulting multidimensional movies can then be analyzed to a) measure the mass function of dark matter substructure; b) measure precise masses of the accreting black holes as well as the structure of their accretion disks and their environments over several decades of physical scale; and c) measure a combination of Hubble's local expansion constant and cosmological distances to unprecedented precision. We present the novel OMEGA instrumentation suite, and how its integrated design is ideal for opening the time domain of known cosmologically-distant variable sources, to achieve the stated scientific goals. C1 [Moustakas, Leonidas A.; Booth, Jeffrey T.; Coe, Dan; Gorjian, Varoujan; Heneghan, Cate; Lawrence, Charles R.; Nikzad, Shouleh] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Moustakas, LA (reprint author), CALTECH, Jet Prop Lab, MS 169-327,4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Moustakas, Leonidas/0000-0003-3030-2360; METCALF, ROBERT BENTON/0000-0003-3167-2574 NR 12 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP B101 EP B101 DI 10.1117/12.789987 PN 1-2 PG 11 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800042 ER PT S AU Booth, J Cropper, M Eisenhauer, F Refregier, A AF Booth, Jeff Cropper, Mark Eisenhauer, Frank Refregier, Alexandre CA DUNE Collaboration BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI The focal plane instrumentation for the DUNE mission - art. no. 70101D SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE Euclid; dark energy; weak lensing; photometric redshift; DUNE; Cosmic Vision; infrared; focal plane array AB DUNE (Dark Universe Explorer) is a proposed mission to measure parameters of dark energy using weak gravitational lensing The particular challenges of both optical and infrared focal planes and the DUNE baseline solution is discussed. The DUNE visible Focal Plane Array (VFP) consists of 36 large format red-sensitive CCDs, arranged in a 9x4 array together with the associated mechanical support structure and electronics processing chains. Four additional CCDs dedicated to attitude control measurements are located at the edge of the array. All CCDs are 4096 pixel red-enhanced e2v CCD203-82 devices with square 12 mu m pixels, operating from 550-920nm. Combining four rows of CCDs provides a total exposure time of 1500s. The VFP will be used in a closed-loop system by the spacecraft, which operates in a drift scan mode, in order to synchronize the scan and readout rates. The Near Infrared (NIR) FPA consists of a 5 x 12 mosaic of 60 Hawaii 2RG detector arrays from Teledyne, NIR bandpass filters for the wavelength bands Y, J, and H, the mechanical support structure, and the detector readout and signal processing electronics. The FPA is operated at a maximum temperature of 140 K for low dark current of 0.02e(-)/s. Each sensor chip assembly has 2048 x 2048 square pixels of 18 mu m size (0.15 arcsec), sensitive in the 0.8 to 1.7 mu m wavelength range. As the spacecraft is scanning the sky, the image motion on the NIR FPA is stabilized by a de-scanning mirror during the integration time of 300 s per detector. The total integration time of 1500 seconds is split among the three NIR wavelengths bands. DUNE has been proposed to ESA's Cosmic Vision program and has been jointly selected with SPACE for an ESA Assessment Phase which has led to the joint Euclid mission concept. C1 [Booth, Jeff] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Booth, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 4 Z9 4 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP D101 EP D101 DI 10.1117/12.790066 PN 1-2 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800043 ER PT S AU Chen, PC Lyon, RG Van Steenberg, ME AF Chen, P. C. Lyon, R. G. Van Steenberg, M. E. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Optical design and in situ fabrication of large telescopes on the moon - art. no. 70104D SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE lunar interferometer; interferometer optical design; in-situ telescope fabrication; large lunar telescope AB We present a novel concept for the optical design and construction of large aperture astronomical telescopes on the Moon. 1. A beam combiner that optically shuffles the 2D non-redundant aperture locations into a I D non-redundant array and brings them to focus on a spectrometer slit thereby encoding all the spatial frequencies of an image at a given wavelength into a I D image, but in such a manner that they are separable and hence allowing for construction of a 2D image at each wavelength. 2. A process to fabricate optical and mechanical components of large telescopes in-situ using regolith material. The optical elements can be of any size. The shapes can be flat or curved. The fabrication process employs simple apparatus that can be robotic in nature. No special high temperature or high pressure equipment is required. C1 [Chen, P. C.] NASA, Goddard Space Flight Ctr, CUA, Greenbelt, MD 20771 USA. RP Chen, PC (reprint author), NASA, Goddard Space Flight Ctr, CUA, Code 671, Greenbelt, MD 20771 USA. RI Lyon, Richard/D-5022-2012 NR 4 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP D104 EP D104 DI 10.1117/12.789945 PN 1-2 PG 4 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800125 ER PT S AU Shi, F King, BM Sigrist, N Basinger, SA AF Shi, Fang King, Brian M. Sigrist, Norbert Basinger, Scott A. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI NIRCam Long Wavelength Channel grisms as the Dispersed Fringe Sensor for JWST segment mirror coarse phasing - art. no. 70102E SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE JWST; wavefront sensing and control; segmented mirrors; Dispersed Fringe Sensor AB The baseline wavefront sensing and control for James Webb Space Telescope (JWST) includes the Dispersed Hartmann Sensors (DHS) for segment mirror coarse phasing. The two DHS devices, residing on the pupil wheel of the JWST's Near Infrared Camera (NIRCam) Short Wavelength Channel (SWC), can sense the JWST segment mirror pistons by measuring the heights of 20 inter-segment edges from the dispersed fringes. JWST also incorporates two identical grisms in the NIRCam's Long Wavelength Channel (LWC). The two grisms, designed as the Dispersed Fringe Sensor (DFS), are used as the backup sensor for JWST segment mirror coarse phasing. The versatility of DFS enables a very flexible JWST segment coarse phasing process and the DFS is designed to have larger piston capture range than that of DHS, making the coarse phasing more robust. The DFS can also be a useful tool during JWST ground integration and test (I&T). In this paper we describe the DFS design details and use the JWST optical model to demonstrate the DFS coarse phasing process during flight and ground I&T. C1 [Shi, Fang; King, Brian M.; Sigrist, Norbert; Basinger, Scott A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Shi, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 4 Z9 4 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP E102 EP E102 DI 10.1117/12.789641 PN 1-2 PG 14 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800072 ER PT S AU Quijada, MA Bousquet, R Garrison, M Perrygo, C Threat, F Rashford, R AF Quijada, Manuel A. Bousquet, Robert Garrison, Matt Perrygo, Chuck Threat, Felix Rashford, Robert BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Optical coating performance for heat reflectors of JWST-ISIM electronic component - art. no. 70103G SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE JWST-ISIM; IEC; thermal radiators; low emittance coatings; BRDF; micro-roughness; bidirectional reflectance; passive cooling AB The James Webb Space Telescope (JWST) consists of an infrared-optimized Optical Telescope Element (OTE) that is cooled down to 40 degrees Kelvin. A second adjacent component to the OTE is the Integrated Science Instrument Module, or ISIM. This module includes the electronic compartment, which provides the mounting surfaces and ambient thermally controlled environment for the instrument control electronics. Dissipating the 200 watts generated from the ISIM structure away from the OTE is of paramount importance so that the spacecraft's own heat does not interfere with the infrared light detected from distant cosmic sources. This technical challenge is overcome by a thermal subsystem unit that provides passive cooling to the ISIM control electronics. The proposed design of this thermal radiator consists of a lightweight structure made out of composite materials and low-emittance metal coatings. In this paper, we will present characterizations of the coating emittance, bidirectional reflectance, and mechanical structure design that will affect the performance of this passive cooling reflector. C1 [Quijada, Manuel A.; Garrison, Matt; Perrygo, Chuck; Threat, Felix] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Quijada, MA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP G103 EP G103 DI 10.1117/12.790521 PN 1-2 PG 11 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800102 ER PT S AU Lyon, RG Gualtieri, JA Belikov, R AF Lyon, Richard G. Gualtieri, John A. Belikov, Ruslan BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Terrestrial planet detection approaches: externally occulted hybrid coronagraphs - art. no. 70101K SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE terrestrial planets; coronagraphy; occulters; starshade; exo-solar; Fourier optics; beam propagation ID SPACE TELESCOPE; STARS AB Externally occulted coronagraphs have garnered widespread attention as a potentially viable approach to starlight suppression to enable direct detection and characterization of exo-solar terrestrial planets. Externally occulted coronagraphs consist of a large mask (occulter) in front of the telescope as compared to an internal coronagraph which performs all suppression within the telescope system using combinations of pupil and/or focal plane masks. The advantages of external over internal are that the (i) inner working angle (IWA) is nearly independent of wavelength and (ii) diffracted light is suppressed prior to the telescope; allowing science over a wide spectral band with a conventional telescope with little or no wavefront control. For an internal coronagraph the IWA generally increases with wavelength and scattered/diffracted light levy exquisite tolerances on wavefront, amplitude and polarization errors. An external coronagraph comes with the added complexity and expense of requiring two spacecraft, flying in formation, at separation distances of tens of thousands of kilometers. Re-targeting requires flying one or both spacecraft and aligning them to the target star and hence added fuel and time as well as closed-loop control between them. One approach may be to construct a smaller occulter possibly at closer distances and use it in series with a simple internal coronagraph, i.e. a hybrid, approach. This may simplify requirements on the external occulter but requires more precise tolerances on the telescope system. The question remains as to whether an acceptable balance between the two approaches exists. Herein we look at one approach to designing a hybrid occulter system. C1 [Lyon, Richard G.; Belikov, Ruslan] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. RP Lyon, RG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP K101 EP K101 DI 10.1117/12.789787 PN 1-2 PG 6 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800049 ER PT S AU CLampin, M AF CLampin, Mark CA Tracer Sci Team BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI The Transit Characterization Explorer (Tracer) - art. no. 70101L SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE exoplanets; spectrograph; telescopes; space science AB The Transit Characterization Explorer (Tracer) is Small Explorer (SMEX) class mission that would characterize the properties of exoplanets that transit their parent star. Tracer will measure the physical conditions, chemistry dynamics and cloud properties of exoplanet atmospheres. Tracer will detect unseen terrestrial planets by observing them directly in transit or by detecting them via perturbations of transit timings. Tracer will return transit light curves that provide robust radii estimates, and can detect planetary rings and/or satellites. Tracer is an ideal SMEX mission presenting the opportunity for timely exploitation of discoveries from the rapid growth of ground-based surveys for transiting systems and providing the ideal complement to missions such as JWST. C1 [CLampin, Mark] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Exoplanet & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. RP CLampin, M (reprint author), NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Exoplanet & Stellar Astrophys Lab, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. RI Clampin, mark/D-2738-2012 NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP L101 EP L101 DI 10.1117/12.790378 PN 1-2 PG 5 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800050 ER PT S AU Feinberg, LD Geithner, PH AF Feinberg, Lee D. Geithner, Paul H. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Applying HST lessons learned to JWST - art. no. 70100N SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE James Webb Space Telescope; JWST; optics; testing; lessons learned; HST AB The James Webb Space Telescope (JWST) is a 6.5 meter cryogenic observatory planned to launch in 2013. The observatory includes a three mirror anastigmat telescope with a deployed 18 segment primary mirror. Unlike the Hubble Space Telescope (HST), JWST will be difficult to service and therefore the development team needs to be highly confident the telescope will work after launch. Consequently, it is imperative that the team building JWST apply the lessons learned from the HST program so as to avoid repeating mistakes that led to a major optical error in HST. The purpose of this paper is to summarize what the JWST program is doing to apply the lessons learned from HST. It includes a summary of how the HST optical error was made, the lessons learned there from, and how the JWST program is applying these lessons to avoid the mistakes of the past and ensure correct JWST optical performance. C1 [Feinberg, Lee D.; Geithner, Paul H.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Feinberg, LD (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP N100 EP N100 DI 10.1117/12.786490 PN 1-2 PG 9 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800022 ER PT S AU Heap, SR Lindler, D Lyon, R AF Heap, Sara R. Lindler, D. Lyon, R. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Detecting biomarkers in exoplanetary atmospheres with a Terrestrial Planet Finder - art. no. 70101N SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE ozone; Terrestrial Planet Finder; exoplanets; detector quantum efficiency; mirror coatings ID OCCULTER AB There are good reasons for extending the spectral range of observation to shorter wavelengths than currently envisaged for terrestrial planet-finding missions utilizing a 4-m, diffraction-limited, optical telescope. The angular resolution at shorter wavelengths is higher, so that the image of an exoplanet is better separated from that of the much brighter star. Due to the higher resolution, the exozodiacal background per resolution element is smaller, so exposure times are reduced for the same incident flux. Most importantly, the sensitivity to the presence of life on habitable exoplanets is increased over a hundred-fold by access to the ozone biomarker in the mid-ultraviolet. These benefits must be weighed against challenges arising from the faintness of exoplanets in the mid-UV. Here, we describe the benefits, technical challenges and some proposed solutions for detecting ozone in the atmospheres of Earth-like exoplanets. C1 [Heap, Sara R.; Lindler, D.; Lyon, R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Heap, SR (reprint author), NASA, Goddard Space Flight Ctr, Code 667, Greenbelt, MD 20771 USA. RI Lyon, Richard/D-5022-2012 NR 13 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP N101 EP N101 DI 10.1117/12.787141 PN 1-2 PG 6 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800051 ER PT S AU Moody, DC Gordon, BL Trauger, JT AF Moody, D. C. Gordon, B. L. Trauger, J. T. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Design and demonstration of hybrid Lyot coronagraph masks for improved spectral bandwidth and throughput - art. no. 70103P SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE coronagraphs; high contrast; active optics; space astronomy ID PLANET; IMAGE; SPACE AB Coronagraph focal-plane occulting masks have generally been described in terms of attenuation profiles free of any phase shift. However, phase shifts are expected and observed in physical occulting masks, with significant effect at billion-to-one coronagraph contrast levels in spectrally broad light, as required for the direct imaging and spectroscopy of nearby exoplanet systems. We report progress in the design and fabrication of hybrid focal-plane masks for Lyot coronagraphy. These masks, composed of thickness-profiled metallic and dielectric thin films superimposed on a glass substrate, are in principle band-limited in both the real and imaginary parts of the occulter characteristics. Together with a deformable mirror for control of wavefront phase, these masks offer Lyot coronagraph contrast performance better than 10(-9) over spectral bandwidths of 30% or more with throughput efficiencies up to 67%. We report recent laboratory coronagraph demonstrations with vacuum-deposited nickel masks on fused silica, and preparations for the fabrication of masks with superimposed metal and dielectric layers. C1 [Moody, D. C.; Gordon, B. L.; Trauger, J. T.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Moody, DC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 14 TC 17 Z9 17 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP P103 EP P103 DI 10.1117/12.790133 PN 1-2 PG 9 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800108 ER PT S AU Rinehart, SA Cheng, E Sirianni, M Mack, J Boyce, K Turczyn, M Emerle, R Waczynski, A Wen, Y Orlowski, I Waligroski, G Trubell, L Albin, K Loose, M Ricardo, R Smith, H Alea, P Meyer, T Auyeung, J AF Rinehart, S. A. Cheng, E. Sirianni, M. Mack, J. Boyce, K. Turczyn, M. Emerle, R. Waczynski, A. Wen, Y. Orlowski, I. Waligroski, G. Trubell, L. Albin, K. Loose, M. Ricardo, R. Smith, H. Alea, P. Meyer, T. Auyeung, J. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Technical aspects of the Advanced Camera for Surveys Repair - art. no. 70104Q SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE Hubble Space Telescope; Servicing Mission 4 ID HUBBLE-SPACE-TELESCOPE AB In January 2007, the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) lost its Wide-Field Channel (WFC) and the High Resolution Channel (HRC) due to a failure in its Low Voltage Power Supply (LVPS). A team was rapidly assembled to determine if the ACS could be repaired as part of HST Servicing Mission 4 (SM4). This team includes contributors from NASA's Goddard Space Flight Center, Ball Aerospace, and Teledyne Imaging Sensors. It determined that all of the capabilities of the ACS could be restored and created a concept for the ACS-Repair (ACS-R) component of SM4. ACS-R will restore the WFC of ACS by replacing the existing CCD Electronics Box (CEB) with the CEB-Replacement (CEB-R) and providing power from a new Low Voltage Power Supply Replacement (LVPS-R). The new LVPS-R will also attempt to restore the HRC function by providing power through the original power bus. In this presentation, we focus on the concept and technical aspects of the ACS-R. C1 [Rinehart, S. A.; Boyce, K.; Turczyn, M.; Smith, H.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Rinehart, SA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP Q104 EP Q104 DI 10.1117/12.789223 PN 1-2 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800138 ER PT S AU Keski-Kuha, RA Saif, B Eegholm, B Blake, P AF Keski-Kuha, Ritva A. Saif, Babak Eegholm, Bente Blake, Peter BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Development of interferometry for testing the JWST Optical Telescope Element (OTE) - art. no. 70100R SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE JWST; speckle pattern interferometry; structural stability; composite structures; multi-wavelength interferometer; testing AB Instantaneous phase shifting interferometry is key to successful development and testing of the large, deployable, cryogenic telescope for the James Webb Space Telescope (JWST) mission. Two new interferometers have been developed to meet the needs of the JWST program. Spatially Phase-Shifted Digital Speckle Pattern Interferometer (SPS-DSPI) was developed to verify structural deformations to nanometer level accuracy in large, deployable, lightweight, precision structures such as the JWST telescope primary mirror backplane. Multi- wavelength interferometer was developed to verify the performance of the segmented primary mirror at cryogenic temperatures. This paper discusses application of SPS-DSPI for measuring structural deformations in large composite structures at cryogenic temperatures. Additionally development of a multi-wavelength interferometer for verifying JWST OTE primary mirror performance at cryogenic temperatures will be discussed. C1 [Keski-Kuha, Ritva A.; Blake, Peter] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. RP Keski-Kuha, RA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. NR 14 TC 0 Z9 0 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP R100 EP R100 DI 10.1117/12.789608 PN 1-2 PG 9 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800026 ER PT S AU Rinehart, SA Domber, J Faulkner, T Gull, T Kimble, R Klappenberger, M Leckrone, D Niedner, M Proffitt, C Smith, H Woodgate, B AF Rinehart, S. A. Domber, J. Faulkner, T. Gull, T. Kimble, R. Klappenberger, M. Leckrone, D. Niedner, M. Proffitt, C. Smith, H. Woodgate, B. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Technical aspects of the Space Telescope Imaging Spectrograph repair (STIS-R) - art. no. 70104R SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE Hubble Space Telescope; Servicing Mission 4 ID ETA-CARINAE; DENSITY; PLANET AB In August 2004, the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) ceased operation due to a failure of the 5V mechanism power converter in the Side 2 Low Voltage Power Supply (LVPS2). The failure precluded movement of any STIS mechanism and, because of the earlier (200 1) loss of the Side I electronics chain, left the instrument shuttered and in safe mode after 7.5 years of science operations. A team was assembled to analyze the fault and to determine if STIS repair (STIS-R) was feasible. The team conclusively pinpointed the Side 2 failure to the 5V mechanism converter, and began studying EVA techniques for opening STIS during Servicing Mission 4 (SM4) to replace the failed LVPS2 board. The restoration of STIS functionality via surgical repair by astronauts has by now reached a mature and final design state, and will, along with a similar repair procedure for the Advanced Camera for Surveys (ACS), represent a first for Hubble servicing. STIS-R will restore full scientific functionality of the spectrograph on Side 2, while Side I will remain inoperative. Because of the high degree of complementarity between STIS and the new Cosmic Origins Spectrograph (COS, to be installed during SM4)), successful repair of the older spectrograph is an important scientific objective. In this presentation, we focus on the technical aspects associated with STIS-R. C1 [Rinehart, S. A.; Gull, T.; Kimble, R.; Leckrone, D.; Niedner, M.; Smith, H.; Woodgate, B.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Rinehart, SA (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 665, Greenbelt, MD 20771 USA. RI Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 NR 12 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP R104 EP R104 DI 10.1117/12.789248 PN 1-2 PG 9 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800139 ER PT S AU Traub, WA Chen, P Kern, B Matsuo, T AF Traub, Wesley A. Chen, Pin Kern, Brian Matsuo, Taro BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Planetseope: An exoplanet coronagraph on a balloon platform - art. no. 70103S SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE coronagraph; balloon; exoplanets; atmospheric seeing; wavefront ID ADAPTIVE OPTICS; TURBULENCE; SCINTILLATION; STRATOSPHERE; SYSTEMS; WAVES AB Direct detection of mature exoplanets is possible using a visible-wavelength telescope and coronagraph in the stratosphere. We analyze two sources of dynamic wavefront perturbations: turbulence in the free atmosphere and locally generated turbulence. We find that they are expected to have relatively small effects on the wavefront. We find that neither source should limit observations at 10(-9) contrast levels for planet-star separations of 0.5 arcsec. On this basis, we expect that it is feasible to image and characterize several known radial-velocity exoplanets. C1 [Traub, Wesley A.; Chen, Pin; Kern, Brian; Matsuo, Taro] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Traub, WA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 16 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP S103 EP S103 DI 10.1117/12.788087 PN 1-2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800111 ER PT S AU Howard, JM Noecker, C Kendrick, S Kilston, S Woodgate, B Cash, W AF Howard, Joseph M. Noecker, Charlie Kendrick, Steve Kilston, Steve Woodgate, Bruce Cash, Webster BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI New Worlds Observer telescope and instrument optical design concepts - art. no. 70103X SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE optical design; optical modeling; terrestrial planet finding; three-mirror-anastigmat AB Optical design concepts for the telescope and instrumentation for NASA's New Worlds Observer program arc presented. A four-meter multiple channel telescope is discussed, as well as a suite of science instrument concepts. Wide field instrumentation (imager and spectrograph) would be accommodated by a three-mirror-anastigmat telescope design. Planet finding and characterization, and a UV instrument would use a separate channel that is picked off after the first two mirrors (primary and secondary). Guiding concepts are also discussed. C1 [Howard, Joseph M.; Woodgate, Bruce] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. RP Howard, JM (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 P SOC PHOTO-OPT INS PY 2008 VL 7010 BP X103 EP X103 DI 10.1117/12.790216 PN 1-2 PG 9 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800114 ER PT S AU Bos, BJ Kubalak, DA Antonille, SR Ohl, RG Hagopian, JG Davila, PS Sullivan, J Sanchez, M Sabatke, D Woodruff, RA te Plate, M Evans, C Isbrucker, V Somerstein, S Wells, M Ronayette, S AF Bos, Brent J. Kubalak, David A. Antonille, Scott R. Ohl, Raymond G. Hagopian, John G. Davila, Pamela S. Sullivan, Joseph Sanchez, Michael Sabatke, Derek Woodruff, Robert A. te Plate, Maurice Evans, Clinton Isbrucker, Victor Somerstein, Stephen Wells, Martyn Ronayette, Samuel BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Cryogenic pupil alignment test architecture for the James Webb Space Telescope integrated science instrument module SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE space telescope; infrared; optical engineering; exit pupil; cryogenic; alignment ID FINE GUIDANCE SENSOR; JWST AB The James Webb Space Telescope (JWST) is a space-based, infrared observatory designed to study the early stages of galaxy formation in the Universe. It is currently scheduled to be launched in 2013 and will go into orbit about the second Lagrange point of the Sun-Earth system and passively cooled to 30-50 K to enable astronomical observations from 0.6 to 28 mu m. The JWST observatory consists of three primary elements: the spacecraft, the optical telescope element (OTE) and the integrated science instrument module (ISIM). The ISIM Element primarily consists of a mechanical metering structure, three science instruments and a fine guidance sensor with significant scientific capability. One of the critical opto-mechanical alignments for mission success is the co-registration of the OTE exit pupil with the entrance pupils of the ISIM instruments. To verify that the ISIM Element will be properly aligned with the nominal OTE exit pupil when the two elements come together, we have developed a cryogenic pupil measurement test architecture to measure three of the most critical pupil degrees-of-freedom during optical testing of the ISIM Element. The pupil measurement scheme makes use of: specularly reflective pupil alignment references located inside of the JWST instruments; ground support equipment that contains a pupil imaging module; an OTE simulator; and pupil viewing channels in two of the JWST flight instruments. Current modeling and analysis activities indicate this measurement approach will be able to verify pupil shear to an accuracy of 0.5-1 %. C1 [Bos, Brent J.; Kubalak, David A.; Antonille, Scott R.; Ohl, Raymond G.; Hagopian, John G.; Davila, Pamela S.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bos, BJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 9 TC 6 Z9 6 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 PROC SPIE PY 2008 VL 7010 AR 70103C DI 10.1117/12.789808 PN 1-2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800099 ER PT S AU Clampin, M AF Clampin, Mark BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Status of the James Webb Space Telescope (JWST) SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE space telescope; large mirrors; cryogenic optics; infrared imaging AB The James Webb Space Telescope (JWST) is a 6.5-meter, space telescope designed for infrared imaging and spectroscopy. Its planned launch in 2013, aboard an Ariane 5, will place it in n L2 orbit. The JWST program is a cooperative program with the Goddard Space Flight Center (GSFC) managing the project for NASA. The prime contractor for JWST is Northrop Grumman Space Technology (NGST). JWST's international partners are the European Space Agency (ESA) and the Canadian Space Agency (CSA). JWST will address four major science themes: First light and re-ionization; the assembly of galaxies, the birth of stars and protoplanetary systems; and the formation of planetary systems and the origins of life. We discuss the design of the observatory as it is currently base-lined, and review recent progress with the observatory. C1 NASA, Goddard Space Flight Ctr, Exoplanet & Stellar Astrophys Lab, Astrophys Sci Div, Greenbelt, MD 20771 USA. RP Clampin, M (reprint author), NASA, Goddard Space Flight Ctr, Exoplanet & Stellar Astrophys Lab, Astrophys Sci Div, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. RI Clampin, mark/D-2738-2012 NR 0 TC 4 Z9 4 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 PROC SPIE PY 2008 VL 7010 AR 70100L DI 10.1117/12.790388 PN 1-2 PG 7 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800020 ER PT S AU Davila, PS Bos, BJ Cheng, ES Chang, B Eichhorn, WL Frey, BJ Garza, M Gong, Q Greeley, BW Guzek, J Hakun, CF Hovmand, L Kirk, J Kubalak, DA Leviton, D Nagle, A Nyquist, R Pham, T Robinson, FD Sabatke, D Sullivan, JF Volmer, P VonHandorf, R Youngworth, RN AF Davila, Pamela S. Bos, Brent J. Cheng, Edward S. Chang, Bill Eichhorn, William L. Frey, Bradley J. Garza, Mario Gong, Qian Greeley, Bradford W. Guzek, Jeff Hakun, Claef F. Hovmand, Lars Kirk, Jeff Kubalak, David A. Leviton, Douglas Nagle, Adrian Nyquist, Rich Pham, Thai Robinson, F. David Sabatke, Derek Sullivan, Joseph F. Volmer, Paul VonHandorf, Rob Youngworth, Richard N. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI The Optical Telescope Element simulator for the James Webb Space Telescope SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE James Webb Space Telescope; telescope; simulator ID ULTRA-HIGH-RESOLUTION AB The James Webb Space Telescope Observatory will consist of three flight elements: (1) the Optical Telescope Element (OTE), (2) the Integrated Science Instrument Module Element (ISIM), and (3) the Spacecraft Element. The ISIM element consists of a composite bench structure that uses kinematic mounts to interface to each of the optical benches of the three science instruments and the guider. The ISIM is also kinematically mounted to the telescope primary mirror structure. An enclosure surrounds the ISIM structure, isolates the ISIM region thermally from the other thermal regions of the Observatory, and serves as a radiator for the science instruments and guider. Cryogenic optical testing of the ISIM Structure and the Science Instruments will be conducted at Goddard Space Flight Center using an optical telescope simulator that is being developed by a team from Ball Aerospace and Goddard Space Flight Center, and other local contractors. This simulator will be used to verify the performance of the ISIM element before delivery to the Northup Grumman team for integration with the OTE. In this paper, we describe the OTE Simulator (OSIM) and provide a brief overview of the optical test program. C1 [Davila, Pamela S.; Bos, Brent J.; Eichhorn, William L.; Frey, Bradley J.; Greeley, Bradford W.; Hakun, Claef F.; Kubalak, David A.; Leviton, Douglas; Pham, Thai] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Davila, PS (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt Rd, Greenbelt, MD 20771 USA. EM Pamela.S.Davila@nasa.gov NR 5 TC 5 Z9 5 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 PROC SPIE PY 2008 VL 7010 AR 70103F DI 10.1117/12.790402 PN 1-2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800101 ER PT S AU Gardner, JP AF Gardner, Jonathan P. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI The scientific capabilities of the James Webb Space Telescope SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE JWST; Webb; space telescope; infrared; science; instrumentation ID GALAXIES AB The scientific capabilities of the James Webb Space Telescope fall into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and active nuclei within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dustenshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. C1 NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Greenbelt, MD 20771 USA. RP Gardner, JP (reprint author), NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Code 665, Greenbelt, MD 20771 USA. EM jonathan.p.gardner@nasa.gov NR 14 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 PROC SPIE PY 2008 VL 7010 AR 70100K DI 10.1117/12.790373 PN 1-2 PG 7 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800019 ER PT S AU Kimble, RA MacKenty, JW O'Connell, RW Townsend, JA AF Kimble, Randy A. MacKenty, John W. O'Connell, Robert W. Townsend, Jacqueline A. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Wide Field Camera 3: a powerful new imager for the Hubble Space Telescope SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE space instruments; ultraviolet; optical; infrared; Bubble Space Telescope; CCDs; infrared arrays AB Wide Field Camera 3 (WFC3) is a powerful UV/visible/near-infrared camera that has just completed development for installation into the Hubble Space Telescope during upcoming Servicing Mission 4. WFC3 provides two imaging channels. The UVIS channel incorporates a 4102 x 4096 pixel CCD focal plane with sensitivity from 200 to 1000 nm and a 162 x 162 arcsec field of view. The UVIS channel features unprecedented sensitivity and field of view in the near ultraviolet for HST, as well as a rich filter set that complements the visible capabilities of the HST/Advanced Camera for Surveys, whose repair will be attempted in the Servicing Mission. The IR channel features a 1024 x 1024 pixel HgCdTe focal plane covering 850 to 1700 nm with a 136 x 123 arcsec field of view, providing a major advance in IR survey efficiency for HST. We report here on the design of the instrument, on recent activities that have completed the integration of the instrument for flight, and on results of the ground test and calibration program. C1 [Kimble, Randy A.; Townsend, Jacqueline A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kimble, RA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM randy.a.kimble@nasa.gov NR 6 TC 25 Z9 25 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 PROC SPIE PY 2008 VL 7010 AR 70101E DI 10.1117/12.789581 PN 1-2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800044 ER PT S AU Kutyrev, AS Collins, N Chambers, J Moseley, SH Rapchun, D AF Kutyrev, A. S. Collins, N. Chambers, J. Moseley, S. H. Rapchun, D. CA Microshutter Team BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Microshutter arrays: High contrast programmable field masks for JWST NIRSpec SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE microshutters; micro-optics; spatial light modulator; programmable aperture masks; micromirror arrays; planar structures ID NEAR-INFRARED SPECTROGRAPH; SPACE-TELESCOPE; MULTIOBJECT AB Microshutter arrays are one of the novel technologies developed for the James Webb Space Telescope (JWST). It will allow Near Infrared Spectrometer (NIRSpec) to acquire spectra of hundreds of objects simultaneously therefore increasing its efficiency tremendously. We have developed these programmable arrays that are based on Micro-Electro Mechanical Structures (MEMS) technology. The arrays are 2D addressable masks that can operate in cryogenic environment of JWST. Since the primary JWST science requires acquisition of spectra of extremely faint objects, it is important to provide very high contrast of the open to closed shutters. This high contrast is necessary to eliminate any possible contamination and confusion in the acquired spectra by unwanted objects. We have developed and built a test system for the microshutter array functional and optical characterization. This system is capable of measuring the contrast of the microshutter array both in visible and infrared light of the NIRSpec wavelength range while the arrays are in their working cryogenic environment. We have measured contrast ratio of several microshutter arrays and demonstrated that they satisfy and in many cases far exceed the NIRSpec contrast requirement value of 2000. C1 [Kutyrev, A. S.] NASA, Goddard Space Flight Ctr, CRESST UMd, Greenbelt, MD 20771 USA. RP Kutyrev, AS (reprint author), NASA, Goddard Space Flight Ctr, CRESST UMd, Code 665, Greenbelt, MD 20771 USA. EM alexander.kutyrev@nasa..gov NR 17 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 PROC SPIE PY 2008 VL 7010 AR 70103D DI 10.1117/12.790192 PN 1-2 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800100 ER PT S AU Traub, WA Kaltenegger, L Jucks, KW AF Traub, Wesley A. Kaltenegger, Lisa Jucks, Kenneth W. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI Spectral characterization of Earth-like transiting exoplanets SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE exoplanet; Earth-like; transit; spectra; SNR AB We calculate the expected signal-to-noise ratio (SNR) for spectral features in the transit spectrum of an Earth-like exoplanet, for the case of the nearest likely transit of a G and an M star, for a 6-m telescope in space. We find that the SNR values for all important spectral features, in the visible and infrared, are in the range 0.2 to 1.1, making the detection of such features difficult. C1 [Traub, Wesley A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Traub, WA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 0 Z9 0 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 PROC SPIE PY 2008 VL 7010 AR 70101O DI 10.1117/12.788095 PN 1-2 PG 4 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800052 ER PT S AU Vasisht, G Swain, MR Akeson, RL Burrows, A Deming, D Grillmair, CJ Greene, TP AF Vasisht, G. Swain, M. R. Akeson, R. L. Burrows, A. Deming, D. Grillmair, C. J. Greene, T. P. BE Oschmann, JM DeGraauw, MWM MacEwen, HA TI THESIS: Terrestrial and habitable zone exoplanet infrared spectroscopy spacecraft SO SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Optical, Infrared and Millimeter CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE extrasolar planets; exoplanets; atmospheres; infrared spectroscopy ID EXTRASOLAR PLANET; HOT JUPITERS; HD 189733B; LIGHT CURVES; WATER-VAPOR; SPECTRUM; ATMOSPHERE; 209458B AB THESIS is a concept for a medium class mission designed for spectroscopic characterization of extrasolar planets between 2-14 microns. The concept leverages off the recent first-steps made by Spitzer and Hubble in characterizing the atmospheres of alien gas giants. Under favourable circumstances, THESIS is capable of identifying biogenic molecules in habitable-zone planets, thereby determining conditions on worlds where life might exist. By systematically characterizing many worlds, from rocky planets to gas-giants, THESIS would deliver transformational science of profound interest to astronomers and the general public. C1 [Vasisht, G.; Swain, M. R.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Vasisht, G (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. EM gv@s383.jpl.nasa.gov; Mark.R.Swain@jpl.nasa.gov NR 27 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7220-5 J9 PROC SPIE PY 2008 VL 7010 AR 70103U DI 10.1117/12.787688 PN 1-2 PG 9 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH63 UT WOS:000259561800113 ER PT S AU Kilbourne, CA Doriese, WB Bandler, SR Brekosky, RP Brown, AD Chervenak, JA Eckart, ME Finkbeiner, FM Hilton, GC Irwin, KD Iyomoto, N Kelley, RL Porter, FS Reinstema, CD Smith, SJ Ullom, JN AF Kilbourne, Caroline A. Doriese, W. Bertrand Bandler, Simon R. Brekosky, Regis P. Brown, Ari-David Chervenak, James A. Eckart, Megan E. Finkbeiner, Fred M. Hilton, Gene C. Irwin, Kent D. Iyomoto, Naoko Kelley, Richard L. Porter, F. Scott Reinstema, Carl D. Smith, Stephen J. Ullom, Joel N. BE Turner, MJL Flanagan, KA TI Multiplexed readout of uniform arrays of TES x-ray micro calorimeters suitable for Constellation-X - art. no. 701104 SO SPACE TELESCOPES AND INSTRUMENTATION 2008: ULTRAVIOLET TO GAMMA RAY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Ultraviolet to Gamma Ray CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE microcalorimeters; transition-edge sensors; time-division SQUID multiplexing; Constellation-X ID TRANSITION-EDGE SENSORS; ABSORBER DESIGN; MICROCALORIMETERS; RESOLUTION; PERFORMANCE; SYSTEM AB Following our development, of a stiperconducting transition-edge-sensor (TES) microcalorimeter design that enables reproducible, high performance (routinely better than 3 eV FWHM energy resolution at 6 keV) and is compatible with high-fill-factor arrays, we have directed our efforts towards demonstrating arrays of identical pixels using the multiplexed read-out concept, needed for istrumenting the Constellation-X X-ray, Microcalorimeter Spectrometer (XMS) focal plane array. We have used a state-of-the-art, dine-division SQUID multiplexer system to demonstrate 2x8 multiplexing (16 pixels read out with two signal channels) with an acceptably modest level of degradation in the energy resolution. The average resolution for the 16 rnultiplexed pixels was 2.9 eV, and the distribution of resolution values had a relative standard deviation of 5%. The performance of the array, while multiplexed is well understood. The technical path to realizing multiplexing for the XMS instrument oil the scale of 32 pixels per signal channel includes increasing the system bandwidth by a factor of four and reducing the non-multiplexed SQUID noise by a factor of two. In this paper we discuss the characteristics of a uniform 8x8 array and its performance when read out non-multiplexed and with various degrees of multiplexing. We present data acquired through the readout chain from the multiplexer electronics, through the real-time demultiplexer software, to storage for later signal processing, We also report on a demonstration of real-tirne data processing. Finally, because the multiplexer provides unprecedented simultaueous access to the pixels of the array, we were able to measure the array-scale uniformity of TES calorimeter parameters such as the individual thermal conductances and superconducting transition temperatures of the pixels. Detector uniformity is essential for optimal operation of a rnultiplexed array, and we found that, the distributions of thermal conductances, transition temperatures, and transition slopes were sufficiently tight, to avoid Significant compromises in the operation of any pixel. C1 [Kilbourne, Caroline A.; Bandler, Simon R.; Brekosky, Regis P.; Brown, Ari-David; Chervenak, James A.; Eckart, Megan E.; Finkbeiner, Fred M.; Iyomoto, Naoko; Kelley, Richard L.; Porter, F. Scott; Smith, Stephen J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kilbourne, CA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Bandler, Simon/A-6258-2010; Smith, Stephen/B-1256-2008; Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Bandler, Simon/0000-0002-5112-8106; Smith, Stephen/0000-0003-4096-4675; Porter, Frederick/0000-0002-6374-1119; NR 18 TC 13 Z9 13 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7221-2 J9 P SOC PHOTO-OPT INS PY 2008 VL 7011 BP 1104 EP 1104 DI 10.1117/12.790027 PN 1-2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH64 UT WOS:000259563700003 ER PT S AU Antonille, S Content, D Rabin, D Wake, S Wallace, T AF Antonille, Scott Content, David Rabin, Doug Wake, Shane Wallace, Thomas BE Turner, MJL Flanagan, KA TI Figure verification of a precision ultra-lightweight mirror: Techniques and results from the SHARPI/PICTURE mirror at NASA/GSFC - art. no. 70110Z SO SPACE TELESCOPES AND INSTRUMENTATION 2008: ULTRAVIOLET TO GAMMA RAY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Ultraviolet to Gamma Ray CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE lightweight mirror; interferometry; aspheric testing; gravity distortion; mount induced distortion; null optic certification; spaceflight optic verification ID FLATS AB A high-precision ultra-lightweight 0.5m mirror with ultraviolet grade tolerances on surface figure quality has been measured from its delivery to the Goddard Space Flight Center, through the coating and mounting process, and shown to survive component vibration testing. This 4.5kg, 0.5m paraboloid mirror is the prime optic of two sounding-rocket telescopes: SHARPI (solar high angular resolution photometric imager) and PICTURE (planet imaging concept testbed using a rocket experiment). By integrating the analysis of interferometer data with finite element models, we demonstrate the ability to isolate surface figure effects comparable to UV diffraction limited tolerances from much larger gravity and mount distortions. The ability to measure Such features paired with in situ monitoring of mirror figure through the mirror mounting process has allowed for a diagnosis of perturbations and the remediation of process errors. In this paper, we describe the technical approach used to achieve nanometer scale measurement accuracy, we report and decompose the final mounted surface figure of 12.5 nm RMS, and we describe the techniques that were developed and employed in the pursuit of maintaining UV diffraction-limited performance with this aggressively lightweighted mirror. C1 [Antonille, Scott; Content, David; Wake, Shane; Wallace, Thomas] NASA, Goddard Space Flight Ctr, Opt Branch, Greenbelt, MD 20771 USA. RP Antonille, S (reprint author), NASA, Goddard Space Flight Ctr, Opt Branch, MC551,Greenbelt Rd, Greenbelt, MD 20771 USA. NR 9 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7221-2 J9 P SOC PHOTO-OPT INS PY 2008 VL 7011 BP Z110 EP Z110 DI 10.1117/12.788962 PN 1-2 PG 15 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH64 UT WOS:000259563700027 ER PT S AU Lyon, RG Carpenter, KG AF Lyon, Richard G. Carpenter, Kenneth G. BE Turner, MJL Flanagan, KA TI Stellar Imager: Wavefront control SO SPACE TELESCOPES AND INSTRUMENTATION 2008: ULTRAVIOLET TO GAMMA RAY, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Ultraviolet to Gamma Ray CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE imaging interferometry; wavefront sensing; wavefront control; phase retrieval; phase diversity; active optics; adaptive optics ID PHASE RETRIEVAL AB Stellar Imager (SI) is a proposed NASA space-based UV imaging interferometer to resolve the stellar disks of nearby stars. SI would consist of 20 - 30 separate spacecraft flying in formation at the Earth-Sun L2 libration point. Onboard wavefront sensing and control is required to maintain alignment during science observations and after array reconfigurations. The Fizeau Interferometry Testbed (FIT), developed at the NASA/Goddard Space Flight Center, is being used to study wavefront sensing and control methodologies for Stellar Imager and other large, sparse aperture telescope systems. FIT initially consists of 7 articulated spherical mirrors in a Golay pattern, and is currently undergoing expansion to 18 elements. FIT currently uses in-focus whitelight sparse aperture PSFs and a direct solve broadband phase retrieval algorithm to sense and control its wavefront. Ultimately it will use extended scene wavelength, with a sequential diversity algorithm that modulates a subset of aperture pistons to jointly estimate the wavefront and the reconstructed image from extended scenes. The recovered wavefront is decomposed into the eigenmodes of the control matrix and actuators are moved to minimize the wavefront piston, tip and tilt in closed-loop. We discuss the testbed, wavefront control methodology and ongoing work to increase its bandwidth from I per I I seconds to a few 10's of Hertz and show ongoing results. C1 [Lyon, Richard G.; Carpenter, Kenneth G.] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. RP Lyon, RG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. RI Carpenter, Kenneth/D-4740-2012 NR 15 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7221-2 J9 PROC SPIE PY 2008 VL 7011 AR 701131 DI 10.1117/12.789758 PN 1-2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH64 UT WOS:000259563700088 ER PT S AU Okajima, T Serlemitsos, PJ Soong, Y Chan, KW Petre, R Ogasaka, Y Miyazawa, T Furuzawa, A Kunieda, H Ishida, M Maeda, Y Tamura, K Mori, H Awaki, H AF Okajima, Takashi Serlemitsos, Peter J. Soong, Yang Chan, Kai-Wing Petre, Rob Ogasaka, Yasushi Miyazawa, Takuya Furuzawa, Akihiro Kunieda, Hideyo Ishida, Manabu Maeda, Yoshitomo Tamura, Keisuke Mori, Hideyuki Awaki, Hisamitsu BE Turner, MJL Flanagan, KA TI Soft X-ray mirrors onboard the NeXT satellite SO SPACE TELESCOPES AND INSTRUMENTATION 2008: ULTRAVIOLET TO GAMMA RAY, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Ultraviolet to Gamma Ray CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE X-ray telescope; soft X-ray; X-ray foil optics ID TELESCOPE AB The New Exploration X-ray Telescope (NeXT) is an X-ray, astronomical observatory slated to be launched from Japan in 2013. Its objectives range from high resolution imaging and spectroscopy, below similar to 12 keV to studyiug the hard X-ray sky up to similar to 70 keV. To accomplish these goals, it will carry, among other instruments, 4 grazing incidence, imaging telescopes, two covering the soft X-ray band and the remaining the higher energies. The soft X-ray telescopes will be similar to ones flown onboard Suzaku, with a larger outer diameter (45 cm) and longer focal length (6 m). The NASA's GSFC foil mirror group is collaborating with the Nagoya University and ISAS/JAXA in the implementation of the the soft, X-ray mirrors. Our science driven goal is a < 1.3' Half Power Diameter (HPD) Point Spread Function, improved from Suzaku similar to 1.7' HPD. We address important area in the fabrication process where we plan to make changes; (1) substrate shaping, (2) replication process, (3) reflector assembly, (4) alignment bar accuracy and (5) focal length miss match among segments. Having done some of them, we measured 1.26' HPD for 60-pair quadrant reflectors. But it still includes bad sectors (> 1.8' HPD) towards the quadrant boundary, while most of middle sectors are at 1' HPD level. The bad sectors can be corrected with new assembly approach where we actively tune and then fix reflectors at their right position or whole conical shell reflectors instead of segmented ones. In this proceeding, we present a proposed NeXT soft X-ray telescope performance, report the current status of the development and introduce the new whole shell mirror. C1 [Okajima, Takashi; Serlemitsos, Peter J.; Soong, Yang; Chan, Kai-Wing; Petre, Rob] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. RP Okajima, T (reprint author), NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Code 662, Greenbelt, MD 20771 USA. EM Takashi.Okajima@nasa.gov NR 10 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7221-2 J9 PROC SPIE PY 2008 VL 7011 AR 70112X DI 10.1117/12.789599 PN 1-2 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH64 UT WOS:000259563700084 ER PT S AU Porter, FS Abbey, TF Bannister, NP Carter, JA Collier, M Cravens, T Evans, M Fraser, GW Galeazzi, M Hills, K Kuntz, K Read, A Robertson, IP Sembey, S Sibeck, DG Snowden, S Stubbs, T Travnicek, P AF Porter, F. Scott Abbey, Tony F. Bannister, Nigel P. Carter, Jenny A. Collier, Michael Cravens, Tom Evans, Mike Fraser, George W. Galeazzi, Massimiliano Hills, Kent Kuntz, Kip Read, Andrew Robertson, Ina P. Sembey, Steve Sibeck, David G. Snowden, Steve Stubbs, Timothy Travnicek, Pavel BE Turner, MJL Flanagan, KA TI The Lunar X-ray Observatory (LXO) SO SPACE TELESCOPES AND INSTRUMENTATION 2008: ULTRAVIOLET TO GAMMA RAY, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Ultraviolet to Gamma Ray CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE X-ray astronomy; charge exchange; solar wind; magnetosheath ID MAGNETIC SHEAR; EMISSION; MAGNETOPAUSE; MAGNETOSHEATH; RECONNECTION; DISCOVERY AB X-ray emission from charge exchange recombination between the highly ionized solar wind and neutral material in Earth's magnetosheath has complicated x-ray observations of celestial objects with x-ray observatories including ROSAT, Chandra, XMM-Newton, and Suzaku. However, the charge-exchange emission can also be used as an important diagnostic of the solar-wind interacting with the magnetosheath. Soft x-ray observations from low-earth orbit or even the highly eccentric orbits of Chandra and XMM-Newton are likely superpositions of the celestial object of interest, the true extra-solar soft x-ray background, geospheric charge exchange, and heliospheric charge exchange. We show that with a small x-ray telescope placed either on the moon, in a similar vein as the Apollo ALSEP instruments, or in a stable orbit at a similar distance from the earth, we can begin to disentangle the complicated emission structure in the soft x-ray band. Here we present initial results of a feasibility study recently funded by NASA to place a small x-ray telescope on the lunar surface. The telescope operates during lunar night to observe charge exchange interactions between the solar wind and magnetosphic neutrals, between the solar wind and the lunar atmosphere, and an unobstructed view of the soft x-ray background without the geospheric component. C1 [Porter, F. Scott; Collier, Michael; Sibeck, David G.; Snowden, Steve; Stubbs, Timothy] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Porter, FS (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM Frederick.S.Porter@nasa.gov RI Porter, Frederick/D-3501-2012; Sibeck, David/D-4424-2012; Stubbs, Timothy/I-5139-2013; Collier, Michael/I-4864-2013; Travnicek, Pavel/G-8608-2014 OI Porter, Frederick/0000-0002-6374-1119; Stubbs, Timothy/0000-0002-5524-645X; Collier, Michael/0000-0001-9658-6605; NR 21 TC 2 Z9 2 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7221-2 J9 PROC SPIE PY 2008 VL 7011 AR 70111L DI 10.1117/12.790182 PN 1-2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH64 UT WOS:000259563700047 ER PT S AU Rohrbach, SO Hadjimichael, TJ Olsen, L Chan, KW Lehan, JP Reid, PB Petre, R O'Dell, SL Saha, TT Zhang, WW AF Rohrbach, S. Owens Hadjimichael, T. J. Olsen, L. Chan, Kai-Wing Lehan, J. P. Reid, P. B. Petre, R. O'Dell, S. L. Saha, T. T. Zhang, W. W. BE Turner, MJL Flanagan, KA TI X-ray imaging tests of Constellation-X SXT mirror segment pairs SO SPACE TELESCOPES AND INSTRUMENTATION 2008: ULTRAVIOLET TO GAMMA RAY, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Ultraviolet to Gamma Ray CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE X-ray optics; x-ray imaging; metrology; performance prediction; integration and test AB The Constellation-X Spectroscopy X-ray Telescope (SXT) is a segmented, tightly nested Wolter-I telescope with a requirement of approximately 12.5" half-power diameter (HPD) for the mirror system. The individual mirror segments are 0.4-mm thick, formed glass, making the task of mounting, alignment and bonding extremely challenging. Over the past year we have developed a series of tools to meet these challenges, the latest of which is an upgrade to the 600-meter x-ray beam line at GSFC. The new facilities allow us to perform full-aperture and sub-aperture imaging tests of mirror segment pairs to locate the source of deformations and correlate them with our optical metrology. We present the optical metrology of the axial figure and Hartmann focus, x-ray imaging performance predictions based on analysis of the optical metrology, and both full-aperture and sub-aperture x-ray imaging performance of test mirror segment pairs at 8.05 keV. C1 [Rohrbach, S. Owens; Petre, R.; Saha, T. T.; Zhang, W. W.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Rohrbach, SO (reprint author), NASA, Goddard Space Flight Ctr, Code 551, Greenbelt, MD 20771 USA. EM Scott.O.Rohrbach@nasa.gov OI O'Dell, Stephen/0000-0002-1868-8056 NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7221-2 J9 PROC SPIE PY 2008 VL 7011 AR 701134 DI 10.1117/12.789838 PN 1-2 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH64 UT WOS:000259563700090 ER PT S AU Smith, SJ Bandler, SR Brekosky, RP Brown, AD Chervenak, JA Eckarta, ME Figueroa-Feliciano, E Finkbeiner, FM Kelley, RL Kilbourne, CA Porter, FS Sadleir, JE AF Smith, Stephen J. Bandler, Simon R. Brekosky, Regis P. Brown, Art -D. Chervenak, Jarnes A. Eckarta, Megan E. Figueroa-Feliciano, Enectali Finkbeiner, Fred M. Kelley, Richard L. Kilbourne, Caroline A. Porter, F. Scott Sadleir, John E. BE Turner, MJL Flanagan, KA TI Development of arrays of position-sensitive microcalorimeters for Constellation-X SO SPACE TELESCOPES AND INSTRUMENTATION 2008: ULTRAVIOLET TO GAMMA RAY, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Ultraviolet to Gamma Ray CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE transition-edge sensor; microcalorimeter; Constellation-X; imaging array; position-sensitive detector ID TRANSITION-EDGE SENSORS; RAY MICROCALORIMETERS; SPECTROSCOPY; DETECTORS AB We are developing arrays of position-sensitive trailsition-edge sensor (PoST) X-ray detectors for future astronomy missions such as NASA's Constellation-X. The PoST consists of multiple absorbers thermally coupled to one or more transition-edge sensor (TES). Each absorber element has a different thermal coupling to the TES. This results in a distribution of different pulse shapes and enables position discrimination between the absorber elements. PoST's are motivated by the desire to achieve the largest possible focal plane area with the fewest number of readout channels and are ideally suited to increasing the Constellation-X focal plane area, without comprising on spatial sampling. Optimizing the performance of PoST's requires careful design of key parameters such as the thermal conductances between the absorbers, TES and the heat sink, as well as the absorber heat capacities. Our new generation of PoST's utilizes technology successfully developed on high resolution (similar to 2.5 eV) single pixels arrays of Mo/Au TESs, also under development for Constellation-V This includes noise mitigation features on the TES and low resistivity electroplated absorbers. We report on the first experimental results from new one-channel, four-pixel, PoST's or 'Hydras', consisting of composite Au/Bi absorbers. We have achieved full-width-at-half-maximum energy resolution of between 5-6 eV on all four Hydra pixels with all exponential decay time constant of 620 mu s. Straightforward position discrimination by means of rise time is also demonstrated. C1 [Smith, Stephen J.; Bandler, Simon R.; Brekosky, Regis P.; Brown, Art -D.; Chervenak, Jarnes A.; Eckarta, Megan E.; Finkbeiner, Fred M.; Kelley, Richard L.; Kilbourne, Caroline A.; Porter, F. Scott; Sadleir, John E.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Smith, SJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM stephen.j.smith@nasa.gov RI Bandler, Simon/A-6258-2010; Smith, Stephen/B-1256-2008; Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Bandler, Simon/0000-0002-5112-8106; Smith, Stephen/0000-0003-4096-4675; Porter, Frederick/0000-0002-6374-1119; NR 18 TC 4 Z9 4 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7221-2 J9 PROC SPIE PY 2008 VL 7011 AR 701126 DI 10.1117/12.790100 PN 1-2 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH64 UT WOS:000259563700059 ER PT S AU Weisskopf, MC Bellazzini, R Costa, E Ramsey, BD O'Dell, SL Elsner, RF Tennant, AF Pavlov, GG Matt, G Kaspi, VM Coppi, PS Wu, KW Siegmund, OHW Zavlin, VE AF Weisskopf, Martin C. Bellazzini, Ronaldo Costa, Enrico Ramsey, Brian D. O'Dell, Stephen L. Elsner, Ronald F. Tennant, Allyn F. Pavlov, George G. Matt, Giorgio Kaspi, Victoria M. Coppi, Paolo S. Wu, Kinwah Siegmund, Oswald H. W. Zavlin, Vyacheslav E. BE Turner, MJL Flanagan, KA TI An imaging X-ray polarimeter for the study of galactic and extragalactic X-ray sources SO SPACE TELESCOPES AND INSTRUMENTATION 2008: ULTRAVIOLET TO GAMMA RAY, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Ultraviolet to Gamma Ray CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE X-ray astronomy; X-ray polarimetry; polarization-sensitive detectors; imaging detectors; X-ray optics ID MAGNETIZED NEUTRON-STARS; SOFT GAMMA-REPEATERS; PULSAR POLAR CAPS; CRAB-NEBULA; BLACK-HOLES; POLARIZATION PROPERTIES; PARTICLE-ACCELERATION; PAIR FORMATION; SLOT GAPS; EMISSION AB Technical progress in X-ray optics and in polarization-sensitive X-ray detectors, which our groups pioneered, enables a scientifically powerful, dedicated space mission for imaging X-ray polarimetry. This mission is sufficiently sensitive to measure X-ray (linear) polarization for a broad range of cosmic sources-primarily those involving neutron stars, stellar black holes, and supermassive black holes (active galactic nuclei). We describe the technical basis, the mission concept, and the physical and astrophysical questions such a mission would address. C1 [Weisskopf, Martin C.; Ramsey, Brian D.; O'Dell, Stephen L.; Elsner, Ronald F.; Tennant, Allyn F.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Weisskopf, MC (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM martin.c.weisskopf@nasa.gov OI Costa, Enrico/0000-0003-4925-8523; O'Dell, Stephen/0000-0002-1868-8056 NR 63 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7221-2 J9 PROC SPIE PY 2008 VL 7011 AR 70111I DI 10.1117/12.788184 PN 1-2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH64 UT WOS:000259563700044 ER PT S AU Zhang, WW Bolognese, J Byron, G Chan, KW Content, DA Hadjimichael, TJ He, C Hill, MD Hong, M Lehan, JP Lozipone, L Mazzarella, JM McClelland, R Nguyen, DT Olsen, L Petre, R Robinson, D Rohrbach, SO Russell, R Saha, TT Sharpe, M Gubarev, MV Jones, WD O'Dell, SL Davis, W Caldwell, DR Freeman, M Podgorski, W Reid, PB AF Zhang, W. W. Bolognese, J. Byron, G. Chan, K. W. Content, D. A. Hadjimichael, T. J. He, Charles Hill, M. D. Hong, M. Lehan, J. P. Lozipone, L. Mazzarella, J. M. McClelland, R. Nguyen, D. T. Olsen, L. Petre, R. Robinson, D. Rohrbach, S. O. Russell, R. Saha, T. T. Sharpe, M. Gubarev, M. V. Jones, W. D. O'Dell, S. L. Davis, W. Caldwell, D. R. Freeman, M. Podgorski, W. Reid, P. B. BE Turner, MJL Flanagan, KA TI Constellation-X mirror technology development SO SPACE TELESCOPES AND INSTRUMENTATION 2008: ULTRAVIOLET TO GAMMA RAY, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Space Telescopes and Instrumentation 2008 - Ultraviolet to Gamma Ray CY JUN 23-28, 2008 CL Marseille, FRANCE SP SPIE, SPIE Europe DE X-ray optics; lightweight optics; Constellation-X; space optics AB As NASA's next major space X-ray observatory, the Constellation-X mission (Bookbinder et al. 2008) requires mirror assemblies with unprecedented characteristics that cannot be provided by existing optical technologies. In the past several years, the project has supported a vigorous mirror technology development program. This program includes the fabrication of lightweight mirror segments by slumping commercially available thin glass sheets, the support and mounting of these thin mirror segments for accurate metrology, the Mounting and attachment of these mirror segments for the purpose of X-ray tests, and development of methods for aligning and integrating these mirror segments into mirror assemblies. This paper describes Our efforts and developments in these areas. C1 [Zhang, W. W.; Bolognese, J.; Chan, K. W.; Hill, M. D.; Nguyen, D. T.; Petre, R.; Robinson, D.; Rohrbach, S. O.; Saha, T. T.; Gubarev, M. V.; Jones, W. D.; O'Dell, S. L.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Zhang, WW (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. OI O'Dell, Stephen/0000-0002-1868-8056 NR 1 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7221-2 J9 PROC SPIE PY 2008 VL 7011 AR 701103 DI 10.1117/12.788453 PN 1-2 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BIH64 UT WOS:000259563700002 ER PT S AU D'Souza, C Clark, F AF D'Souza, Christopher Clark, Fred BE Seago, JH Neta, B Eller, TJ Pelletier, FJ TI Linear Covariance analysis techniques applied to Orion cislunar operations SO SPACEFLIGHT MECHANICS 2008, VOL 130, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 18th Space Flight Mechanics Meeting CY JAN 28-FEB 01, 2008 CL Galveston, TX SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB Linear Covariance techniques are applied to the cislunar phase of the Orion mission. Both the guidance and navigation system is analyzed particularly as it relates to 3 sigma navigation performance and trajectory dispersion. In addition the Delta V statistics will be presented. This paper documents the preliminary integrated analyses performed to provide the expected onboard dispersion and navigation errors. C1 [D'Souza, Christopher] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP D'Souza, C (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-544-2 J9 ADV ASTRONAUT SCI PY 2008 VL 130 BP 3 EP 22 PN 1-2 PG 20 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIC52 UT WOS:000258397800001 ER PT S AU Folta, DC Mesarch, MA Miller, R AF Folta, David C. Mesarch, Michael A. Miller, Ronald BE Seago, JH Neta, B Eller, TJ Pelletier, FJ TI A lunar relay mission design and navigation initiative using existing NASA resources SO SPACEFLIGHT MECHANICS 2008, VOL 130, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 18th Space Flight Mechanics Meeting CY JAN 28-FEB 01, 2008 CL Galveston, TX SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB The Space Communications and Navigation, Constellation Integration Project (SCIP), formerly the Lunar Communications and Navigation Systems (LCNS) work area within Exploration Communications and Navigation Systems (ECANS), is tasked with defining, developing, deploying and operating an evolving multi-decade communications and navigation infrastructure at the moon including services and subsystems that will support both robotic and human exploration activities. This paper discusses a proposed initiative for an early demonstration of lunar relay orbits using the existing WIND and Wilkinson Microwave Anisotropy Probe (WMAP) spacecraft to meet several needs of the SCIP. Transfer from a Sun-Earth co-linear libration orbit (L-1 and L-2) into Earth-moon co-linear and lunar relay orbits is analyzed and the rationale, implementation, and benefits of Such a demonstration are provided. C1 [Folta, David C.; Mesarch, Michael A.] NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 USA. RP Folta, DC (reprint author), NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-544-2 J9 ADV ASTRONAUT SCI PY 2008 VL 130 BP 41 EP 59 PN 1-2 PG 19 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIC52 UT WOS:000258397800003 ER PT S AU Carpenter, R Lee, T AF Carpenter, Russell Lee, Taesul BE Seago, JH Neta, B Eller, TJ Pelletier, FJ TI A stable clock error model using coupled first- and second-order Gauss-Markov processes SO SPACEFLIGHT MECHANICS 2008, VOL 130, PTS 1 AND 2 SE Advances in the Astronautical Sciences LA English DT Proceedings Paper CT AAS/AIAA 18th Space Flight Mechanics Meeting CY JAN 28-FEB 01, 2008 CL Galveston, TX SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB Long data outages may occur in applications of global navigation satellite system technology to orbit determination for missions that spend significant fractions of their orbits above the navigation satellite constellation(s). Current clock error models based on the random walk idealization may not be suitable in these circumstances, since the covariance of the clock errors may become large enough to overflow flight computer arithmetic. A model that is stable, but which approximates the existing models over short time horizons is desirable. A coupled first- and second-order Gauss-Markov process is such a model. C1 [Carpenter, Russell] NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 USA. RP Carpenter, R (reprint author), NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Code 595, Greenbelt, MD 20771 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-544-2 J9 ADV ASTRONAUT SCI PY 2008 VL 130 BP 151 EP 162 PN 1-2 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIC52 UT WOS:000258397800010 ER PT S AU Stough, RW Heaton, AF Whorton, MS AF Stough, Robert W. Heaton, Andrew F. Whorton, Mark S. BE Seago, JH Neta, B Eller, TJ Pelletier, FJ TI Chasing a comet with a solar sail SO SPACEFLIGHT MECHANICS 2008, VOL 130, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 18th Space Flight Mechanics Meeting CY JAN 28-FEB 01, 2008 CL Galveston, TX SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB Solar sail propulsion systems enable a wide range of missions that require constant thrust or high delta-V over long mission times. One particularly challenging mission type is a comet rendezvous mission. This paper presents optimal low-thrust trajectory designs for a range of sailcraft performance metrics and mission transit times that enables a comet rendezvous mission. These optimal trajectory results provide a trade space which can be parameterized in terms of mission duration and sailcraft performance so that a design space for a small satellite comet chaser mission is identified. These results show that a low-cost comet rendezvous with solar sails is feasible. C1 [Stough, Robert W.; Heaton, Andrew F.; Whorton, Mark S.] NASA, George C Marshall Space Flight Ctr, Nav & Miss Anal Branch, Huntsville, AL 35812 USA. RP Stough, RW (reprint author), NASA, George C Marshall Space Flight Ctr, Nav & Miss Anal Branch, EV42, Huntsville, AL 35812 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-544-2 J9 ADV ASTRONAUT SCI PY 2008 VL 130 BP 1101 EP 1111 PN 1-2 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIC52 UT WOS:000258397800067 ER PT S AU Shoemaker, NS Kupelian, CG Doyon, GP Ozanne, J Percival, JW Jaehnig, KP McCandliss, SR Lupu, R Hall, RA Clark, MS AF Shoemaker, Neil S. Kupelian, Charles G. Doyon, Gerard P. Ozanne, John Percival, Jeffrey W. Jaehnig, Kurt P. McCandliss, Stephan R. Lupu, Roxana Hall, Ronald A. Clark, Mark S. BE Seago, JH Neta, B Eller, TJ Pelletier, FJ TI Sub-arcsecond attitude control for sounding rocket payloads SO SPACEFLIGHT MECHANICS 2008, VOL 130, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 18th Space Flight Mechanics Meeting CY JAN 28-FEB 01, 2008 CL Galveston, TX SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB Sounding rockets have been used to obtain observation time above 100 km for more than 50 years. Payloads have ranged from a few pounds to just over 1200 lbs. Scientific objectives have ranged from atmospheric studies to plasma physics to astrophysics. Attitude control has been achieved with solenoid valves that deliver cold gas to expansion nozzles. Pointing precision has approached +/- 1 arcsec for each axis. C1 [Shoemaker, Neil S.; Kupelian, Charles G.; Doyon, Gerard P.; Ozanne, John] Wallops Flight Facil, NSROC, Wallops Isl, VA 23337 USA. RP Shoemaker, NS (reprint author), Wallops Flight Facil, NSROC, Wallops Isl, VA 23337 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-544-2 J9 ADV ASTRONAUT SCI PY 2008 VL 130 BP 1735 EP 1747 PN 1-2 PG 13 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIC52 UT WOS:000258397800107 ER PT S AU Folta, DC AF Folta, David C. BE Seago, JH Neta, B Eller, TJ Pelletier, FJ TI Historical examination of improvements to libration point trajectory design SO SPACEFLIGHT MECHANICS 2008, VOL 130, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 18th Space Flight Mechanics Meeting CY JAN 28-FEB 01, 2008 CL Galveston, TX SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut ID MISSION AB Over the years, NASA has experienced a fundamental change in how mission analysis and operations are performed. With knowledge that various perturbations play a significant role, the mission designer must rely on both traditional design strategies as well as innovative methods. Over the past decades, improvements have been made that would at first glance seem dramatic. This paper provides a brief historical narrative on how a fundamental shift has occurred, and how 'chaos' dynamics improve the design of missions with complex constraints. Beginning with the trajectory design of the ISEE-3 mission using optimization tools on mainframes, moving onto WIND trajectory design using differential correctors on PCs, and ending with JWST use of dynamical system theory of manifolds and stable modes, lessons learned from decades of continuous technical improvement are presented along with whether these methods promise to have a significant impact on future space mission design. C1 NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 USA. RP Folta, DC (reprint author), NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-544-2 J9 ADV ASTRONAUT SCI PY 2008 VL 130 BP 1831 EP 1844 PN 1-2 PG 14 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIC52 UT WOS:000258397800114 ER PT S AU Gillam, SD Ionasescu, R Williams, P AF Gillam, Stephen D. Ionasescu, Rodica Williams, Powtawche BE Seago, JH Neta, B Eller, TJ Pelletier, FJ TI The planning of optical navigation pictures for the Cassini extended mission SO SPACEFLIGHT MECHANICS 2008, VOL 130, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 18th Space Flight Mechanics Meeting CY JAN 28-FEB 01, 2008 CL Galveston, TX SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB This paper describes the optical navigation image (opnav) planning for the Cassini extended mission, which includes nine low-altitude flybys of the icy satellites including seven of Enceladus, one of Dione and one of Rhea. Two of the Enceladus flybys have closest approach altitudes at or below 50 km. We present studies showing how much the uncertainties in the Enceladus ephemeris can be reduced by the inclusion of opnavs in the orbit determination. We show that the planned opnavs will maintain the precision of the satellite ephemerides to support the close flybys, cover periods of poor radiometric data during solar conjunctions, and provide a backup data type during the short periods between the two double flybys (where an icy satellite is flown by immediately preceding or following a Titan flyby, and Titan alone is targeted). The processes and software needed to compute the windows of observing opportunity for each satellite, making the initial selection of targets, and refining the selections in response to changes in the tour design during the process are dealt with. Opnavs often conflict with proposed science observations. The process for resolving these conflicts is described. The distribution and timing of opnavs in the extended mission navigation plan is presented to show that the plan meets the needs stated above. The need to periodically replan (mostly repoint) pictures during the extended mission in response to reference trajectory updates is explored and it is shown that the same techniques used to plan the opnavs can be used to replan them. C1 [Gillam, Stephen D.; Ionasescu, Rodica; Williams, Powtawche] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gillam, SD (reprint author), CALTECH, Jet Prop Lab, MS 230-205,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-544-2 J9 ADV ASTRONAUT SCI PY 2008 VL 130 BP 2003 EP 2018 PN 1-2 PG 16 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIC52 UT WOS:000258397800126 ER PT B AU Lutz, R AF Lutz, Robyn BA Geppert, B BF Geppert, B BE Pohl, K TI Enabling Verifiable Conformance for Product Lines SO SPLC 2008: 12TH INTERNATIONAL SOFTWARE PRODUCT LINE CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 12th International Software Product Line Conference CY SEP 08-12, 2008 CL Limerick, IRELAND SP Software Engn Inst, Carnegie Mellon, Irish Comp Soc, BigLever, MKS, Syst Log, Pure Syst, Telelogic ID SOFTWARE REUSE; EXPERIENCE; FAMILY AB NASA is, with the rest of industry, turning to product-line engineering to reduce costs and improve quality by effectively managing reuse. Experience in industry has shown that it is the verifiable conformance of each system to the product-line specifications that makes or breaks the product-line practice. Verification that the software for each project satisfies its intended product-line constraints is thus essential. This paper reports early results from an effort to assemble from previous, industrial experience a set of enablers of verifiable conformance for use in the application engineering of NASA product lines. Lessons learned may be useful for developers of safety critical, long-lived, or highly autonomous product lines, as well as for companies that integrate product line subsystems developed by multiple contractors. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Lutz, R (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 33 TC 3 Z9 3 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 978-0-7695-3303-2 PY 2008 BP 35 EP 44 DI 10.1109/SPLC.2008.12 PG 10 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BII25 UT WOS:000259669800004 ER PT J AU Mckay, CP AF Mckay, Christopher P. BE Botta, O Bada, JL GomezElvira, J Javaux, E Selsis, F Summons, R TI An Approach to Searching for Life on Mars, Europa, and Enceladus SO STRATEGIES OF LIFE DETECTION SE Space Science Series of ISSI LA English DT Article; Book Chapter DE Life; Mars; Europa; Enceladus; Second genesis ID GLOBAL DISTRIBUTION AB Near-term missions may be able to access samples of organic material from Mars, Europa, and Enceladus. The challenge for astrobiology will be to determine if this material is the remains of dead microorganisms or merely abiotic organic material. The remains of life that shares a common origin with life on Earth will be straightforward to detect using sophisticated methods such as DNA amplification. These methods are extremely sensitive but specific to Earth-like life. Detecting the remains of alien life-that does not have a genetic or biochemical commonality with Earth life-will be much more difficult. There is a general property of life that can be used to determine if organic material is of biological origin. This general property is the repeated use of a few specific organic molecules for the construction of biopolymers. For example, Earth-like life uses 20 amino acids to construct proteins, 5 nucleotide bases to construct DNA and RNA, and a few sugars to construct polysaccharides. This selectivity will result in a statistically anomalous distribution of organic molecules distinct from organic material of non-biological origin. Such a distinctive pattern, different from the pattern of Earth-like life, will be persuasive evidence for a second genesis of life. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Mckay, CP (reprint author), NASA, Ames Res Ctr, Div Space Sci, Mail Stop 245-3, Moffett Field, CA 94035 USA. EM cmckay@mail.arc.nasa.gov NR 15 TC 0 Z9 0 U1 2 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 978-0-387-77516-6 J9 SPACE SCI SER ISSI PY 2008 VL 25 BP 49 EP 54 DI 10.1007/978-0-387-77516-6_6 D2 10.1007/978-0-387-77516-6 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BNI58 UT WOS:000274636600006 ER PT J AU Mahaffy, P AF Mahaffy, Paul BE Botta, O Bada, JL GomezElvira, J Javaux, E Selsis, F Summons, R TI Exploration of the Habitability of Mars: Development of Analytical Protocols for Measurement of Organic Carbon on the 2009 Mars Science Laboratory SO STRATEGIES OF LIFE DETECTION SE Space Science Series of ISSI LA English DT Article; Book Chapter DE Mars; Organics; Mars Science Laboratory; Sample Analysis at Mars Investigation; Astrobiology ID MARTIAN METEORITE ALH84001; POLYCYCLIC AROMATIC-HYDROCARBONS; CHROMATOGRAPHY-MASS-SPECTROMETRY; IN-SITU ANALYSES; AMINO-ACIDS; ATMOSPHERE; METHANE; SURFACE; SEARCH; ORIGIN AB The mission goal of the 2009 Mars Science Laboratory is to assess the habitability of a region on Mars. This large rover incorporates an Analytical Laboratory that contributes to this mission objective by means of a detailed characterization of mineralogy and chemistry. The Sample Analysis at Mars instrument suite in the Analytical Laboratory provides the capability to analyze volatiles released from rocks and soils and gases directly sample from the atmosphere. A primary focus of this suite is the detection and identification of organic molecules. The protocols for the extraction and analysis of organics under development for this mission are described as are experiments carried out on Mars analog samples to evaluate these methods. C1 NASA, Goddard Space Flight Ctr, Atmospher Expt Lab, Greenbelt, MD 20771 USA. RP Mahaffy, P (reprint author), NASA, Goddard Space Flight Ctr, Atmospher Expt Lab, Greenbelt, MD 20771 USA. EM Paul.R.Mahaffy@nasa.gov RI Mahaffy, Paul/E-4609-2012 NR 51 TC 0 Z9 0 U1 1 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 978-0-387-77516-6 J9 SPACE SCI SER ISSI PY 2008 VL 25 BP 255 EP 268 DI 10.1007/978-0-387-77516-6_18 D2 10.1007/978-0-387-77516-6 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BNI58 UT WOS:000274636600018 ER PT J AU Bada, JL Ehrenfreund, P Grunthaner, F Blaney, D Coleman, M Farrington, A Yen, A Mathies, R Amudson, R Quinn, R Zent, A Ride, S Barron, L Botta, O Clark, B Glavin, D Hofmann, B Josset, JL Rettberg, P Robert, F Sephton, M AF Bada, J. L. Ehrenfreund, P. Grunthaner, F. Blaney, D. Coleman, M. Farrington, A. Yen, A. Mathies, R. Amudson, R. Quinn, R. Zent, A. Ride, S. Barron, L. Botta, O. Clark, B. Glavin, D. Hofmann, B. Josset, J. L. Rettberg, P. Robert, F. Sephton, M. BE Botta, O Bada, JL GomezElvira, J Javaux, E Selsis, F Summons, R TI Urey: Mars Organic and Oxidant Detector SO STRATEGIES OF LIFE DETECTION SE Space Science Series of ISSI LA English DT Article; Book Chapter DE Mars; Life detection instrumentation; Space research ID ATACAMA DESERT; MARTIAN SOIL; AMINO-ACIDS; LIFE; ATMOSPHERE; PRESERVATION; REACTIVITY; MOLECULES; METHANE; SEARCH AB One of the fundamental challenges facing the scientific community as we enter this new century of Mars research is to understand, in a rigorous manner, the biotic potential both past and present of this outermost terrestrial-like planet in our solar system. Urey: Mars Organic and Oxidant Detector has been selected for the Pasteur payload of the European Space Agency's (ESA's) ExoMars rover mission and is considered a fundamental instrument to achieve the mission's scientific objectives. The instrument is named Urey in recognition of Harold Clayton Urey's seminal contributions to cosmochemistry, geochemistry, and the study of the origin of life. The overall goal of Urey is to search for organic compounds directly in the regolith of Mars and to assess their origin. Urey will perform a groundbreaking investigation of the Martian environment that will involve searching for organic compounds indicative of life and prebiotic chemistry at a sensitivity many orders of magnitude greater than Viking or other in situ organic detection systems. Urey will perform the first in situ search for key classes of organic molecules using state-of-the-art analytical methods that provide part-per-trillion sensitivity. It will ascertain whether any of these molecules are abiotic or biotic in origin and will evaluate the survival potential of organic compounds in the environment using state-of-the-art chemoresistor oxidant sensors. C1 [Bada, J. L.] Scripps Inst Oceanog, La Jolla, CA 92093 USA. [Ehrenfreund, P.] Leiden Inst Chem, NL-2300 Leiden, Netherlands. [Grunthaner, F.; Blaney, D.; Coleman, M.; Farrington, A.; Yen, A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Mathies, R.; Amudson, R.] Univ Calif Berkeley, Berkeley, CA 94720 USA. [Quinn, R.] NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. [Ride, S.] Imaginary Lines Inc, San Diego, CA 92122 USA. [Barron, L.] Univ Glasgow, Dept Chem, Glasgow G12 8QQ, Lanark, Scotland. [Botta, O.] Int Space Sci Inst, CH-3012 Bern, Switzerland. [Clark, B.] Lockheed Martin, Space Explorat Syst, Denver, CO 80201 USA. [Glavin, D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Hofmann, B.] Nat Hist Museum Burgergemeinde Bern, CH-3005 Bern, Switzerland. [Josset, J. L.] Space Explorat Inst SPACE X, Neuchatel, Switzerland. [Rettberg, P.] Inst Aerosp Med Radiat Biol, D-51147 Cologne, Germany. [Robert, F.] Museum Natl Hist Nat, LEME NanoAnal, F-75005 Paris, France. [Sephton, M.] Univ London Imperial Coll Sci Technol & Med, Dept Earth Sci & Engn, London SW7 2AZ, England. RP Bada, JL (reprint author), Scripps Inst Oceanog, La Jolla, CA 92093 USA. EM jbada@ucsd.edu; jbada@ucsd.edu NR 36 TC 0 Z9 0 U1 2 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 978-0-387-77516-6 J9 SPACE SCI SER ISSI PY 2008 VL 25 BP 269 EP 279 DI 10.1007/978-0-387-77516-6_19 D2 10.1007/978-0-387-77516-6 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BNI58 UT WOS:000274636600019 ER PT B AU Draper, SL Lerch, BA AF Draper, S. L. Lerch, B. A. BE Kim, YW Morris, D Yang, R Leyens, C TI Durability assessment of tial alloys SO STRUCTURAL ALUMINIDES FOR ELEVATED TEMPERATURES: GAMMA TITANIUM AND OTHER: METALLIC ALUMINIDES LA English DT Proceedings Paper CT Structural Aluminides for Elevated Temperatures Symposium held at the TMS 2008 Annual Meeting and Exhibition CY MAR 09-13, 2008 CL New Orleans, LA SP Minerals, Metals and Mat Soc, Structural Mat Div DE embrittlement; ballistic impact; fatigue ID GAMMA-MET PX; TEMPERATURE EXPOSURE; TI-48AL-2NB-2CR; BEHAVIOR AB The durability of TiAl is a prime concern for the implementation of TiAl into aerospace engines. Two durability issues, the effect of high temperature exposure on mechanical properties and impact resistance, have been investigated and the results are summarized in this paper. Exposure to elevated temperatures has been shown to be detrimental to the room temperature ductility of gamma alloys with die most likely mechanisms being the ingress of interstitials front the surface. Fluorine ion implantation has been shown to improve the oxidation resistance of gamma alloys, and ideally it could also improve the environmental embrittlement of high Nb content TiAl alloys. The effect of F ion implantation on the surface oxidation and embrittlement of a third generation, high Nb content TiAl alloy (Ti-45Al-5Nb-B-C) were investigated. Additionally, the ballistic impact resistance of a variety of gamma alloys, including Ti-48Al-2Cr-2Nb, Ti-47Al-2Cr-2Nb, ABB-2, ABB-23, NCG359E, 95A and Ti-45Al-5Nb-B-C was accessed. Differences in the ballistic impact properties of the various alloys will be discussed, particularly with respect to their manufacturing process, microstructure, and tensile properties. C1 [Draper, S. L.; Lerch, B. A.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Draper, SL (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 978-0-87339-720-9 PY 2008 BP 39 EP 50 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BIB82 UT WOS:000258313300007 ER PT B AU Rappazzo, AF Velli, M Einaudi, G AF Rappazzo, A. F. Velli, M. Einaudi, G. BE Howe, R Komm, RW Balasubramaniam, KS Petrie, GJD TI The parker scenario for coronal heating as an MHD turbulence problem SO SUBSURFACE AND ATMOSPHERIC INFLUENCES ON SOLAR ACTIVITY SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT 24th National Solar Observatory Sacramento Peak Workshop CY APR 16-20, 2007 CL Natl Solar Observ, Sacramento Peak, NM SP Natl Solar Observ, Natl Sci Fdn, Natl Aeronaut & Space Adm, Air Force Off Sci Res HO Natl Solar Observ ID MAGNETOHYDRODYNAMIC TURBULENCE; ALFVENIC TURBULENCE; SOLAR CORONA; LOOPS; STATISTICS; NANOFLARES; ANISOTROPY; SPECTRUM; ENERGY; FIELDS AB The Parker or field line tangling model of coronal heating is investigated through long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry within the framework of reduced magnetohydrodynamics (RMHD). Slow photospheric motions induce a Poynting flux which saturates by driving an anisotropic turbulent cascade dominated by magnetic energy and characterized by current sheets elongated along the axial magnetic field. Increasing the value of the axial magnetic field different regimes of MHD turbulence develop with a bearing on coronal heating rates. In physical space magnetic field lines at the scale of convection cells appear only slightly bended in agreement with observations of large loops of current (E)UV and X-ray imagers. C1 [Rappazzo, A. F.; Velli, M.] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. [Velli, M.] Univ Florence, Dipartimento Astron Scienza dello Spazio, Florence 50125, Italy. [Einaudi, G.] Univ Pisa, Dipartimento Fis Fermi, I-56127 Pisa, Italy. RP Rappazzo, AF (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. FU NASA; NASA LWS FX A.F.R. is supported by the NASA Postdoctoral Program, M.V. is supported by NASA LWS TR&T and SR&T. A.F.R. and M.V. thank the IPAM program Grand Challenge Problems in Computational Astrophysics at UCLA. NR 34 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-329-4 J9 ASTR SOC P PY 2008 VL 383 BP 353 EP + PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHO72 UT WOS:000254887200040 ER PT B AU Nathal, MV AF Nathal, Michael V. BE Reed, RC Green, KA Caron, P Gabb, TP Fahrmann, MG Huron, ES TI NASA and superalloys: A customer, a participant, and a referee SO SUPERALLOYS 2008 LA English DT Proceedings Paper CT 11th International Symposium on Superalloys CY SEP 14-18, 2008 CL Champion, PA SP TMS, ASM Int, TMS High Temperature Alloys Comm DE superalloys; shape memory alloys; Stirling engines; power systems AB NASA has had a long history of research and development in the field of superalloys. These efforts have continued today, where the latest advancements in turbine disk and blade technologies are being developed Although NASA does support military flight systems, it's predominant role is in supporting civilian air transportation systems, and thus has goals for improving fuel efficiency, emissions, noise, and safety of today's aircraft. NASA has traditionally served several distinct but complimentary roles as participants in multi-disciplinary research teams, as customers who fund research and development efforts at industry and universities, and as referees who can address broad issues that affect the entire aeronautics community. Because of our longer range viewpoint, we can take on higher risk, higher reward research topics. NASA can also serve as an intermediary between the basic research performed primarily at universities and the development efforts emphasized by industry. By interacting with individual companies, NASA can identify areas of general interest and problems common to a large portion of the aeronautics community, and devise programs aimed at solving these problems. In space missions, NASA is a direct Customer responsible for developing vehicles. In the case of the Space Shuttle, NASA has worked with various contractors to design and build numerous components out of superalloys. Another fascinating area for the use of superalloys is in power systems for long life applications in space. Potential missions include providing electric power for deep space missions, surface rovers, including lunar and Mars, and stationary power generators on the lunar surface. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Nathal, MV (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 25 TC 3 Z9 3 U1 1 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 978-0-87339-728-5 PY 2008 BP 13 EP 19 PG 7 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BIG92 UT WOS:000259400800002 ER PT B AU Gabb, TP Gayda, J Telesman, J Garg, A AF Gabb, Timothy P. Gayda, John Telesman, Jack Garg, Anita BE Reed, RC Green, KA Caron, P Gabb, TP Fahrmann, MG Huron, ES TI The effects of heat treatment and microstructure variations on disk superalloy properties at high temperature SO SUPERALLOYS 2008 LA English DT Proceedings Paper CT 11th International Symposium on Superalloys CY SEP 14-18, 2008 CL Champion, PA SP TMS, ASM Int, TMS High Temperature Alloys Comm DE disk; superalloys; microstructure AB The effects of heat treatment and resulting microstructure variations on high temperature mechanical properties were assessed for a powder metallurgy disk superalloy LSHR. Blanks were consistently supersolvus solution heat treated and quenched at two cooling rates, than aged at varying temperatures and times. Tensile, creep, and dwell fatigue crack growth tests were then performed at 704 degrees C. gamma' precipitate microstructures were quantified. Relationships between heat treatment-microstructure, heat treatment-mechanical properties, and microstructure-mechanical properties were assessed. C1 [Gabb, Timothy P.; Gayda, John; Telesman, Jack] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Gabb, TP (reprint author), NASA, Glenn Res Ctr, 21000 Brookpark Rd, Cleveland, OH 44135 USA. NR 19 TC 10 Z9 10 U1 0 U2 4 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 978-0-87339-728-5 PY 2008 BP 121 EP 130 PG 10 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BIG92 UT WOS:000259400800013 ER PT B AU Telesman, J Gabb, TP Garg, A Bonaclise, P Gayda, J AF Telesman, J. Gabb, T. P. Garg, A. Bonaclise, P. Gayda, J. BE Reed, RC Green, KA Caron, P Gabb, TP Fahrmann, MG Huron, ES TI Effect of microstructure on time dependent fatigue crack growth behavior in a P/M turbine disk alloy SO SUPERALLOYS 2008 LA English DT Proceedings Paper CT 11th International Symposium on Superalloys CY SEP 14-18, 2008 CL Champion, PA SP TMS, ASM Int, TMS High Temperature Alloys Comm DE hold time crack growth; microstructure; P/M superalloys; stress relaxation; precipitate size distribution AB A study was conducted to determine the processes which govern hold time crack growth behavior in the LSHR disk P/M superalloy. Nineteen different heat treatments of this alloy were evaluated by systematically controlling the cooling rate from the supersolvus solutioning step and applying various single and double step aging treatments. The resulting hold time crack growth rates varied by more than two orders of magnitude. It was shown that the associated stress relaxation behavior for these heat treatments was closely correlated with the crack growth behavior. As stress relaxation increased, the hold time crack growth resistance was also increased. The size of the tertiary gamma' in the general microstructure was found to be the key microstructural variable controlling both the hold time crack growth behavior and stress relaxation. No relationship between the presence of grain boundary M23C6 carbides and hold time crack growth was identified which further brings into question the importance of the grain boundary phases in determining hold time crack growth behavior. The linear elastic fracture mechanics parameter, Kmax, is unable to account for visco-plastic redistribution of the crack tip stress field during hold times and thus is inadequate for correlating time dependent crack growth data. A novel methodology was developed which captures the intrinsic crack driving force and was able to collapse hold time crack growth data onto a single curve. C1 [Telesman, J.; Gabb, T. P.; Gayda, J.] NASA Glenn, Cleveland, OH 44135 USA. RP Telesman, J (reprint author), NASA Glenn, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 11 TC 26 Z9 26 U1 0 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 978-0-87339-728-5 PY 2008 BP 807 EP 816 PG 10 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BIG92 UT WOS:000259400800089 ER PT B AU Liverman, D AF Liverman, Diana BE Shuckburgh, E TI Survival into the future SO SURVIVAL: THE SURVIVAL OF THE HUMAN RACE SE Darwin College Lectures LA English DT Article; Book Chapter ID CLIMATE-CHANGE C1 [Liverman, Diana] NOAA, Washington, DC USA. [Liverman, Diana] NASA, Washington, DC USA. [Liverman, Diana] Univ Oxford, Environm Change Inst, Oxford OX1 2JD, England. NR 9 TC 0 Z9 0 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI CAMBRIDGE PA THE PITT BUILDING, TRUMPINGTON ST, CAMBRIDGE CB2 1RP, CAMBS, ENGLAND BN 978-0-521-71020-6 J9 DARWIN COLL LECT PY 2008 BP 205 EP 224 PG 20 WC Environmental Sciences; Environmental Studies SC Environmental Sciences & Ecology GA BYS02 UT WOS:000299938400009 ER PT J AU Estabrook, FB AF Estabrook, Frank B. TI Exterior Differential Systems for Yang-Mills Theories SO SYMMETRY INTEGRABILITY AND GEOMETRY-METHODS AND APPLICATIONS LA English DT Article DE exterior differential systems; Cartan characters; Maxwell equations; SU(2)-Yang-Mills equations AB Exterior differential systems are given, and their Cartan characters calculated, for Maxwell and SU(2)-Yang-Mills equations in dimensions from three to six. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Estabrook, FB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM frank.b.estabrook@jpl.nasa.gov NR 9 TC 1 Z9 1 U1 0 U2 0 PU NATL ACAD SCI UKRAINE, INST MATH PI KYIV 4 PA 3 TERESCHCHENKIV SKA ST, KYIV 4, 01601, UKRAINE SN 1815-0659 J9 SYMMETRY INTEGR GEOM JI Symmetry Integr. Geom. PY 2008 VL 4 AR 063 DI 10.3842/SIGMA.2008.063 PG 4 WC Physics, Mathematical SC Physics GA 461LF UT WOS:000267267800063 ER PT J AU Acikmese, B Corless, M AF Acikmese, Behcet Corless, Martin TI Stability analysis with quadratic lyapunov functions: Some necessary and sufficient multiplier conditions SO SYSTEMS & CONTROL LETTERS LA English DT Article DE stability; robust stability; quadratic stability; lyapunov; nonlinear systems; uncertain systems; KYP lemma ID UNCERTAIN LINEAR-SYSTEMS; STABILIZABILITY; STABILIZATION AB In this paper, we present several conditions which are both necessary and sufficient for quadratic stability of an uncertain/nonlinear system. These conditions involve multiplier matrices which characterize the uncertain/nonlinear terms in the system description. It is known that some of these conditions are sufficient for quadratic stability. One of the main contributions of this paper is to demonstrate that these conditions are also necessary conditions, hence, they are not conservative conditions for quadratic stability. By presenting multiplier matrices for many common types of uncertain/nonlinear terms, the paper also demonstrates the usefulness of the multiplier matrix approach in the analysis and control of nonlinear/time-varying/uncertain systems. (C) 2007 Elsevier B.V. All rights reserved. C1 Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. [Acikmese, Behcet] Jet Propuls Lab, Guidance Control Anal Grp, Pasadena, CA USA. RP Corless, M (reprint author), Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. EM behcet@jpl.nasa.gov; corless@purdue.edu RI Corless, Martin/F-2299-2011 NR 28 TC 17 Z9 17 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6911 J9 SYST CONTROL LETT JI Syst. Control Lett. PD JAN PY 2008 VL 57 IS 1 BP 78 EP 94 DI 10.1016/j.sysconle.2007.06.018 PG 17 WC Automation & Control Systems; Operations Research & Management Science SC Automation & Control Systems; Operations Research & Management Science GA 243XO UT WOS:000251830800011 ER PT S AU Ando, M Kawamura, S Nakamura, T Tsubono, K Tanaka, T Funaki, I Seto, N Numata, K Sato, S Ioka, K Kanda, N Takashima, T Agatsuma, K Akutsu, T Akutsu, T Aoyanagi, K Arai, K Arase, Y Araya, A Asada, H Aso, Y Chiba, T Ebisuzaki, T Enoki, M Eriguchi, Y Fujimoto, MK Fujita, R Fukushima, M Futamase, T Ganzu, K Harada, T Hashimoto, T Hayama, K Hikida, W Himemoto, Y Hirabayashi, H Hiramatsu, T Hong, FL Horisawa, H Hosokawa, M Ichiki, K Ikegami, T Inoue, KT Ishidoshiro, K Ishihara, H Ishikawa, T Ishizaki, H Ito, H Itoh, Y Kamagasako, S Kawashima, N Kawazoe, F Kirihara, H Kishimoto, N Kiuche, K Kobayashi, S Kohri, K Koizumi, H Kojima, Y Kokeyama, K Kokuyama, W Kotake, K Kozai, Y Kudoh, H Kunimori, H Kuninaka, H Kuroda, K Maeda, KI Matsuhara, H Mino, Y Miyakawa, O Miyoki, S Morimoto, MY Morioka, T Morisawa, T Moriwaki, S Mukohyama, S Musha, M Nagano, S Naito, I Nakagawa, N Nakamura, K Nakano, H Nakao, K Nakasuka, S Nakayama, Y Nishida, E Nishiyama, K Nishizawa, A Niwa, Y Ohashi, M Ohishi, N Ohkawa, M Okutomi, A Onozato, K Oohara, K Sago, N Saijo, M Sakagami, M Sakai, S Sakata, S Sasaki, M Sato, T Shibata, M Shinkai, H Somiya, K Sotani, H Sugiyama, N Suwa, Y Tagoshi, H Takahashi, K Takahashi, K Takahashi, T Takahashi, H Takahashi, R Takahashi, R Takamori, A Takano, T Taniguchi, K Taruya, A Tashiro, H Tokuda, M Tokunari, M Toyoshima, M Tsujikawa, S Tsunesada, Y Ueda, KI Utashima, M Yamakawa, H Yamamoto, K Yamazaki, T Yokoyama, J Yoo, CM Yoshida, S Yoshino, T AF Ando, Masaki Kawamura, Seiji Nakamura, Takashi Tsubono, Kimio Tanaka, Takahiro Funaki, Ikkoh Seto, Naoki Numata, Kenji Sato, Shuichia Ioka, Kunihito Kanda, Nobuyuki Takashima, Takeshi Agatsuma, Kazuhiro Akutsu, Tomotada Akutsu, Tomomi Aoyanagi, Koh-suke Arai, Koji Arase, Yuta Araya, Akito Asada, Hideki Aso, Yoichi Chiba, Takeshi Ebisuzaki, Toshikazu Enoki, Motohiro Eriguchi, Yoshiharu Fujimoto, Masa-Katsu Fujita, Ryuichi Fukushima, Mitsuhiro Futamase, Toshifumi Ganzu, Katsuhiko Harada, Tomohiro Hashimoto, Tatsuaki Hayama, Kazuhiro Hikida, Wataru Himemoto, Yoshiaki Hirabayashi, Hisashi Hiramatsu, Takashi Hong, Feng-Lei Horisawa, Hideyuki Hosokawa, Mizuhiko Ichiki, Kiyotomo Ikegami, Takeshi Inoue, Kaiki T. Ishidoshiro, Koji Ishihara, Hideki Ishikawa, Takehiko Ishizaki, Hideharu Ito, Hiroyuki Itoh, Yousuke Kamagasako, Shogo Kawashima, Nobuki Kawazoe, Fumiko Kirihara, Hiroyuki Kishimoto, Naoko Kiuche, Kenta Kobayashi, Shiho Kohri, Kazunori Koizumi, Hiroyuki Kojima, Yasufumi Kokeyama, Keiko Kokuyama, Wataru Kotake, Kei Kozai, Yoshihide Kudoh, Hideaki Kunimori, Hiroo Kuninaka, Hitoshi Kuroda, Kazuaki Maeda, Kei-ichi Matsuhara, Hideo Mino, Yasushi Miyakawa, Osamu Miyoki, Shinji Morimoto, Mutsuko Y. Morioka, Tomoko Morisawa, Toshiyuki Moriwaki, Shigenori Mukohyama, Shinji Musha, Mitsuru Nagano, Shigeo Naito, Isao Nakagawa, Noriyasu Nakamura, Kouji Nakano, Hiroyuki Nakao, Kenichi Nakasuka, Shinichi Nakayama, Yoshinori Nishida, Erina Nishiyama, Kazutaka Nishizawa, Atsushi Niwa, Yoshito Ohashi, Masatake Ohishi, Naoko Ohkawa, Masashi Okutomi, Akira Onozato, Kouji Oohara, Kenichi Sago, Norichika Saijo, Motoyuki Sakagami, Masaaki Sakai, Shin-ichiro Sakata, Shihori Sasaki, Misao Sato, Takashi Shibata, Masaru Shinkai, Hisaaki Somiya, Kentaro Sotani, Hajime Sugiyama, Naoshi Suwa, Yudai Tagoshi, Hideyuki Takahashi, Kakeru Takahashi, Keitaro Takahashi, Tadayuki Takahashi, Hirotaka Takahashi, Ryuichi Takahashi, Ryutaro Takamori, Akiteru Takano, Tadashi Taniguchi, Keisuke Taruya, Atsushi Tashiro, Hiroyuki Tokuda, Mitsuru Tokunari, Masao Toyoshima, Morio Tsujikawa, Shinji Tsunesada, Yoshiki Ueda, Ken-ichi Utashima, Masayoshi Yamakawa, Hiroshi Yamamoto, Kazuhiro Yamazaki, Toshitaka Yokoyama, Jun'ichi Yoo, Chul-Moon Yoshida, Shijun Yoshino, Taizoh BE Inoue, K Suzuki, A Mitsuri, T TI DECIGO Pathfinder SO TAUP2007: TENTH INTERNATIONAL CONFERENCE ON TOPICS IN ASTROPARTICLE AND UNDERGROUND PHYSICS SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 10th International Conference on Topics in Astroparticle and Underground Physics CY SEP 11-15, 2007 CL Sendai, JAPAN SP Tohoku Univ, Res Ctr Neutrino Sci ID GRAVITATIONAL-WAVE ANTENNA; SPACE AB DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected to provide us fruitful insights into the universe, in particular about dark energy, a fori-nation mechanism of supermassive black holes, and the inflation of the universe. Since DECIGO will be an extremely large mission which will formed by three drag-free spacecraft with 1000m separation, it is significant to gain the technical feasibility of DECIGO before its planned launch in 2024. Thus, we are planning to launch two milestone missions: DPF and pre-DECIGO. The conceptual design and current status of the first milestone mission, DPF, are reviewed in this article. C1 [Ando, Masaki; Tsubono, Kimio; Agatsuma, Kazuhiro; Akutsu, Tomotada; Akutsu, Tomomi; Arase, Yuta; Hiramatsu, Takashi; Ichiki, Kiyotomo; Ishidoshiro, Koji; Kamagasako, Shogo; Kirihara, Hiroyuki; Koizumi, Hiroyuki; Kokuyama, Wataru; Kudoh, Hideaki; Morioka, Tomoko; Mukohyama, Shinji; Nakagawa, Noriyasu; Nakasuka, Shinichi; Okutomi, Akira; Onozato, Kouji; Suwa, Yudai; Takahashi, Kakeru; Taruya, Atsushi; Tokunari, Masao; Yokoyama, Jun'ichi] Univ Tokyo, Grad Sch Sci, Bunkyo Ku, Tokyo 1130033, Japan. [Kawamura, Seiji; Sato, Shuichia; Arai, Koji; Fujimoto, Masa-Katsu; Fukushima, Mitsuhiro; Hayama, Kazuhiro; Ichiki, Kiyotomo; Nakamura, Kouji; Sugiyama, Naoshi; Takahashi, Ryuichi; Takahashi, Ryutaro; Yamazaki, Toshitaka] Natl Astronom Observ Japan, Mitaka, Tokyo 1818588, Japan. [Nakamura, Takashi; Tanaka, Takahiro; Ioka, Kunihito; Ganzu, Katsuhiko; Harada, Tomohiro; Morisawa, Toshiyuki; Tashiro, Hiroyuki] Kyoto Univ, Grad Sch Sci, Kyoto 6068502, Japan. [Seto, Naoki; Mino, Yasushi; Miyakawa, Osamu] CALTECH, Pasadena, CA 91125 USA. [Numata, Kenji] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Hosokawa, Mizuhiko; Nagano, Shigeo] Natl Inst Informat & Commun Technol, Koganei, Tokyo 1848795, Japan. [Ishikawa, Takehiko] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Tsukuba, Ibaraki 3058505, Japan. [Musha, Mitsuru; Ueda, Ken-ichi] Univ Elect Commun, Inst Laser Sci, Chofu, Tokyo 1828585, Japan. [Ohkawa, Masashi; Sato, Takashi] Niigata Univ, Fac Engn, Niigata 9502181, Japan. [Aoyanagi, Koh-suke; Kiuche, Kenta; Maeda, Kei-ichi; Sotani, Hajime; Yoshida, Shijun] Waseda Univ, Sci & Engn, Tokyo 1698555, Japan. [Araya, Akito] Univ Tokyo, Earthquake Res Inst, Tokyo 1130032, Japan. [Asada, Hideki] Hirosaki Univ, Fac Sci & Technol, Hirosaki, Aomori 0368560, Japan. [Chiba, Takeshi] Nihon Univ Setagaya, Coll Human & Sci, Tokyo 1568550, Japan. [Ebisuzaki, Toshikazu] RIKEN, Wako, Saitama 3510198, Japan. [Eriguchi, Yoshiharu; Shibata, Masaru] Univ Tokyo, Grad Sch Arts & Sci, Tokyo 1538902, Japan. [Futamase, Toshifumi] Tohoku Univ, Grad Sch Sci, Sendai, Miyagi 9808578, Japan. [Hashimoto, Tatsuaki; Hirabayashi, Hisashi; Matsuhara, Hideo; Takano, Tadashi] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. [Hikida, Wataru; Sasaki, Misao] Kyoto Univ, Yukawa Inst Theoret Phys, Kyoto 6068502, Japan. [Ikegami, Takeshi] Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058563, Japan. [Inoue, Kaiki T.; Kawashima, Nobuki] Kinki Univ, Sch Sci & Engn, Osaka 5778502, Japan. [Itoh, Yousuke] Univ Wisconsin Milwaukee, Milwaukee, WI 53201 USA. [Kanda, Nobuyuki; Nakano, Hiroyuki; Nakao, Kenichi; Yoo, Chul-Moon] Osaka City Univ, Grad Sch Sci, Osaka 5588585, Japan. [Kobayashi, Shiho] Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead L41 1LD, Merseyside, England. [Kohri, Kazunori] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Kojima, Yasufumi] Hiroshima Univ, Grad Sch Sci, Hiroshima 7398526, Japan. [Kokeyama, Keiko] Ochanomizu Univ, Grad Sch Human & Sci, Tokyo 1128610, Japan. [Kozai, Yoshihide] Gunma Astronom Observ, Gunma 3770702, Japan. [Kunimori, Hiroo] Natl Inst Informat & Commun Technol, Tokyo 1130001, Japan. [Kuroda, Kazuaki; Miyoki, Shinji; Ohashi, Masatake; Yamamoto, Kazuhiro] Univ Tokyo, Inst Cosmic Ray Res, Chiba 2778582, Japan. Niigata Univ, Fac Sci, Niigata 9502181, Japan. [Nishizawa, Atsushi; Niwa, Yoshito; Sakagami, Masaaki] Kyoto Univ, Fac Intergrated Human Studies, Kyoto 6068501, Japan. [Sago, Norichika; Tagoshi, Hideyuki] Osaka Univ, Grad Sch Sci, Toyonaka, Osaka 5600043, Japan. [Saijo, Motoyuki] Observ Paris, Sect Meudon, F-92195 Meudon, France. [Shinkai, Hisaaki] INAMORI Fdn, Kyoto 6008411, Japan. [Somiya, Kentaro; Takahashi, Hirotaka] Max Planck Inst Gravitat Phys, D-14476 Potsdam, Germany. [Taniguchi, Keisuke] Univ Illinois, Dept Phys, Urbana, IL 61801 USA. [Tsunesada, Yoshiki] Tokyo Inst Technol, Grad Sch Sci & Engn, Tokyo 1528550, Japan. [Yoshino, Taizoh] Nakamura Minami, Tokyo 1760025, Japan. RP Ando, M (reprint author), Univ Tokyo, Grad Sch Sci, Bunkyo Ku, Tokyo 1130033, Japan. EM ando@granite.phys.s.u-tokyo.ac.jp RI Kawazoe, Fumiko/F-7700-2011; ANDO, MASAKI/G-4989-2014; Hong, Feng-Lei/N-3098-2014 OI ANDO, MASAKI/0000-0002-8865-9998; Hong, Feng-Lei/0000-0003-1318-2635 FU Ministry of Education, Science, Sports and Culture; Japan Aerospace Exploration Agency FX This research was partially supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research, and by the Japan Aerospace Exploration Agency NR 4 TC 2 Z9 3 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2008 VL 120 AR 032005 DI 10.1088/1742-6596/120/3/032005 PG 5 WC Physics, Applied; Physics, Particles & Fields SC Physics GA BIX23 UT WOS:000263552900016 ER PT S AU Kawamura, S Ando, M Nakamura, T Tsubono, K Tanaka, T Funaki, I Seto, N Numata, K Sato, S Ioka, K Kanda, N Takashima, T Agatsuma, K Akutsu, T Akutsu, T Aoyanagi, KS Arai, K Arase, Y Araya, A Asada, H Aso, Y Chiba, T Ebisuzaki, T Enoki, M Eriguchi, Y Fujimoto, MK Fujita, R Fukushima, M Futamase, T Ganzu, K Harada, T Hashimoto, T Hayama, K Hikida, W Himemoto, Y Hirabayashi, H Hiramatsu, T Hong, FL Horisawa, H Hosokawa, M Ichiki, K Ikegami, T Inoue, KT Ishidoshiro, K Ishihara, H Ishikawa, T Ishizaki, H Ito, H Itoh, Y Kamagasako, S Kawashima, N Kawazoe, F Kirihara, H Kishimoto, N Kiuchi, K Kobayashi, S Kohri, K Koizumi, H Kojima, Y Kokeyama, K Kokuyama, W Kotake, K Kozai, Y Kudoh, H Kunimori, H Kuninaka, H Kuroda, K Maeda, K Matsuhara, H Mino, Y Miyakawa, O Miyoki, S Morimoto, MY Morioka, T Morisawa, T Moriwaki, S Mukohyama, S Musha, M Nagano, S Naito, I Nakagawa, N Nakamura, K Nakano, H Nakao, K Nakasuka, S Nakayama, Y Nishida, E Nishiyama, K Nishizawa, A Niwa, Y Ohashi, M Ohishi, N Ohkawa, M Okutomi, A Onozato, K Oohara, K Sago, N Saijo, M Sakagami, M Sakai, S Sakata, S Sasaki, M Sato, T Shibata, M Shinkai, H Somiya, K Sotani, H Sugiyama, N Suwa, Y Tagoshi, H Takahashi, K Takahashi, K Takahashi, T Takahashi, H Takahashi, R Takahashi, R Takamori, A Takano, T Taniguchi, K Taruya, A Tashiro, H Tokuda, M Tokunari, M Toyoshima, M Tsujikawa, S Tsunesada, Y Ueda, K Utashima, M Yamakawa, H Yamamoto, K Yamazaki, T Yokoyama, J Yoo, CM Yoshida, S Yoshino, T AF Kawamura, Seiji Ando, Masaki Nakamura, Takashi Tsubono, Kimio Tanaka, Takahiro Funaki, Ikkoh Seto, Naoki Numata, Kenji Sato, Shuichi Ioka, Kunihito Kanda, Nobuyuki Takashima, Takeshi Agatsuma, Kazuhiro Akutsu, Tomotada Akutsu, Tomomi Aoyanagi, Koh-suke Arai, Koji Arase, Yuta Araya, Akito Asada, Hideki Aso, Yoichi Chiba, Takeshi Ebisuzaki, Toshikazu Enoki, Motohiro Eriguchi, Yoshiharu Fujimoto, Masa-Katsu Fujita, Ryuichi Fukushima, Mitsuhiro Futamase, Toshifumi Ganzu, Katsuhiko Harada, Tomohiro Hashimoto, Tatsuaki Hayama, Kazuhiro Hikida, Wataru Himemoto, Yoshiaki Hirabayashi, Hisashi Hiramatsu, Takashi Hong, Feng-Lei Horisawa, Hideyuki Hosokawa, Mizuhiko Ichiki, Kiyotomo Ikegami, Takeshi Inoue, Kaiki T. Ishidoshiro, Koji Ishihara, Hideki Ishikawa, Takehiko Ishizaki, Hideharu Ito, Hiroyuki Itoh, Yousuke Kamagasako, Shogo Kawashima, Nobuki Kawazoe, Fumiko Kirihara, Hiroyuki Kishimoto, Naoko Kiuchi, Kenta Kobayashi, Shiho Kohri, Kazunori Koizumi, Hiroyuki Kojima, Yasufumi Kokeyama, Keiko Kokuyama, Wataru Kotake, Kei Kozai, Yoshihide Kudoh, Hideaki Kunimori, Hiroo Kuninaka, Hitoshi Kuroda, Kazuaki Maeda, Kei-ichi Matsuhara, Hideo Mino, Yasushi Miyakawa, Osamu Miyoki, Shinji Morimoto, Mutsuko Y. Morioka, Tomoko Morisawa, Toshiyuki Moriwaki, Shigenori Mukohyama, Shinji Musha, Mitsuru Nagano, Shigeo Naito, Isao Nakagawa, Noriyasu Nakamura, Kouji Nakano, Hiroyuki Nakao, Kenichi Nakasuka, Shinichi Nakayama, Yoshinori Nishida, Erina Nishiyama, Kazutaka Nishizawa, Atsushi Niwa, Yoshito Ohashi, Masatake Ohishi, Naoko Ohkawa, Masashi Okutomi, Akira Onozato, Kouji Oohara, Kenichi Sago, Norichika Saijo, Motoyuki Sakagami, Masaaki Sakai, Shin-ichiro Sakata, Shihori Sasaki, Misao Sato, Takashi Shibata, Masaru Shinkai, Hisaaki Somiya, Kentaro Sotani, Hajime Sugiyama, Naoshi Suwa, Yudai Tagoshi, Hideyuki Takahashi, Kakeru Takahashi, Keitaro Takahashi, Tadayuki Takahashi, Hirotaka Takahashi, Ryuichi Takahashi, Ryutaro Takamori, Akiteru Takano, Tadashi Taniguchi, Keisuke Taruya, Atsushi Tashiro, Hiroyuki Tokuda, Mitsuru Tokunari, Masao Toyoshima, Morio Tsujikawa, Shinji Tsunesada, Yoshiki Ueda, Ken-ichi Utashima, Masayoshi Yamakawa, Hiroshi Yamamoto, Kazuhiro Yamazaki, Toshitaka Yokoyama, Jun'ichi Yoo, Chul-Moon Yoshida, Shijun Yoshino, Taizoh BE Inoue, K Suzuki, A Mitsuri, T TI The Japanese Space Gravitational Wave Antenna; DECIGO SO TAUP2007: TENTH INTERNATIONAL CONFERENCE ON TOPICS IN ASTROPARTICLE AND UNDERGROUND PHYSICS SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 10th International Conference on Topics in Astroparticle and Underground Physics CY SEP 11-15, 2007 CL Sendai, JAPAN SP Tohoku Univ, Res Ctr Neutrino Sci AB DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. DECIGO is expected to open a new window of observation for gravitational wave astronomy especially between 0.1 Hz and 10 Hz, revealing various mysteries of the universe such as dark energy, formation mechanism of supermassive black holes, and inflation of the universe. The pre-conceptual design of DECIGO consists of three drag-free spacecraft, whose relative displacements are measured by a differential Fabry-Perot Michelson interferometer. We plan to launch two missions, DECIGO pathfinder and pre-DECIGO first and finally DECIGO in 2024. C1 [Kawamura, Seiji; Seto, Naoki; Sato, Shuichi; Arai, Koji; Fujimoto, Masa-Katsu; Fukushima, Mitsuhiro; Ishizaki, Hideharu; Kotake, Kei; Nakamura, Kouji; Ohishi, Naoko; Takahashi, Ryutaro; Yamamoto, Kazuhiro; Yamazaki, Toshitaka] Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan. [Nakamura, Takashi; Tanaka, Takahiro; Ioka, Kunihito; Ganzu, Katsuhiko; Harada, Tomohiro; Morisawa, Toshiyuki; Tashiro, Hiroyuki] Kyoto Univ, Grad Sch Sci, Kyoto 6068502, Japan. [Ando, Masaki; Tsubono, Kimio; Agatsuma, Kazuhiro; Akutsu, Tomotada; Aso, Yoichi; Himemoto, Yoshiaki; Hiramatsu, Takashi; Ishidoshiro, Koji; Kamagasako, Shogo; Kirihara, Hiroyuki; Kudoh, Hideaki; Mukohyama, Shinji; Nakagawa, Noriyasu; Okutomi, Akira; Taruya, Atsushi; Tokunari, Masao; Tsujikawa, Shinji; Yokoyama, Jun'ichi] Univ Tokyo, Grad Sch Sci, Tokyo 1130033, Japan. [Seto, Naoki; Mino, Yasushi; Miyakawa, Osamu] CALTECH, Pasadena, CA 91125 USA. [Numata, Kenji] NASA Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Hosokawa, Mizuhiko; Nagano, Shigeo] Natl Inst Informat & Commun Technol, Koganei, Tokyo 1848795, Japan. [Ishikawa, Takehiko] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Tsukuba, Ibaraki 3058505, Japan. [Musha, Mitsuru; Ueda, Ken-ichi] Univ Elect Commun, Inst Laser Sci, Chofu, Tokyo 1828585, Japan. [Ohkawa, Masashi; Sato, Takashi] Niigata Univ, Fac Engn, Niigata 9502181, Japan. [Aoyanagi, Koh-suke; Kiuchi, Kenta; Maeda, Kei-ichi; Sotani, Hajime; Yoshida, Shijun] Waseda Univ, Sci & Engn, Tokyo 1698555, Japan. [Araya, Akito] Univ Tokyo, Earthquake Res Inst, Tokyo 1130032, Japan. [Asada, Hideki] Hirosaki Univ, Fac Sci & Technol, Hirosaki, Aomori 0368560, Japan. [Chiba, Takeshi] Nihon Univ Setagaya, Coll Humanities & Sci, Tokyo 1568550, Japan. [Ebisuzaki, Toshikazu] RIKEN, Wako, Saitama 3510198, Japan. [Eriguchi, Yoshiharu; Shibata, Masaru] Univ Tokyo, Grad Sch Arts & Sci, Tokyo 1538902, Japan. [Futamase, Toshifumi] Tohoku Univ, Grad Sch Sci, Sendai, Miyagi 9808578, Japan. [Hashimoto, Tatsuaki; Hirabayashi, Hisashi; Matsuhara, Hideo; Takahashi, Tadayuki; Takano, Tadashi] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. [Hikida, Wataru; Sasaki, Misao] Kyoto Univ, Yukawa Inst Theoret Phys, Kyoto 6068502, Japan. [Ikegami, Takeshi] Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058563, Japan. [Inoue, Kaiki T.; Kawashima, Nobuki] Kinki Univ, Sch Sci & Engn, Osaka 5778502, Japan. [Itoh, Yousuke] Univ Wisconsin Milwaukee, Milwaukee, WI 53201 USA. [Kanda, Nobuyuki; Nakano, Hiroyuki; Nakao, Kenichi; Yoo, Chul-Moon] Osaka City Univ, Grad Sch Sci, Osaka 5588585, Japan. [Kobayashi, Shiho] Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead L41 1LD, Merseyside, England. [Kohri, Kazunori] Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 USA. [Kojima, Yasufumi] Hiroshima Univ, Grad Sch Sci, Hiroshima 7398526, Japan. [Kokeyama, Keiko; Sakata, Shihori] Ochanomizu Univ, Grad Sch Human & Sci, Taipei 1128610, Taiwan. [Kozai, Yoshihide] Gunma Astronom Observ, Gunma 3770702, Japan. [Kunimori, Hiroo] Natl Inst Informat & Commun Technol, Tokyo 1130001, Japan. [Kuroda, Kazuaki; Miyoki, Shinji; Ohashi, Masatake; Yamamoto, Kazuhiro] Univ Tokyo, Inst Cosmic Ray Res, Chiba 2778582, Japan. Niigata Univ, Fac Sci, Niigata 9502181, Japan. [Naito, Isao] Kyoto Univ, Fac Intergrated Human Studies, Kyoto 6068501, Japan. [Nishizawa, Atsushi; Niwa, Yoshito; Sakagami, Masaaki] Kyoto Univ, Fac Intergrated Human Studies, Kyoto 6068501, Japan. [Sago, Norichika; Tagoshi, Hideyuki] Osaka Univ, Grad Sch Sci, Toyonaka, Osaka 5600043, Japan. [Saijo, Motoyuki] Observ Paris, F-92195 Meudon, France. [Shinkai, Hisaaki] INAMORI Fdn, Kyoto 6008411, Japan. [Somiya, Kentaro; Takahashi, Hirotaka] Max Planck Inst Gravitat Phys, D-14476 Potsdam, Germany. [Taniguchi, Keisuke] Univ Illinois, Dept Phys, Urbana, IL 61801 USA. [Tsunesada, Yoshiki] Tokyo Inst Technol, Grad Sch Sci & Engn, Tokyo 1528550, Japan. [Yoshino, Taizoh] Nakamura Minami, Tokyo 1760025, Japan. RP Kawamura, S (reprint author), Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan. EM seiji.kawamura@nao.ac.jp RI Kawazoe, Fumiko/F-7700-2011; Suwa, Yudai/G-9711-2012; Hong, Feng-Lei/N-3098-2014; ANDO, MASAKI/G-4989-2014 OI Hong, Feng-Lei/0000-0003-1318-2635; ANDO, MASAKI/0000-0002-8865-9998 FU Ministry of Education, Science, Sports and Culture FX This research was partially supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research. NR 7 TC 11 Z9 11 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2008 VL 120 AR 032004 DI 10.1088/1742-6596/120/3/032004 PG 5 WC Physics, Applied; Physics, Particles & Fields SC Physics GA BIX23 UT WOS:000263552900015 ER PT J AU McCleese, DJ AF McCleese, Daniel J. TI Mars SO TECHNOLOGY REVIEW LA English DT Letter C1 Jet Propuls Lab, Pasadena, CA USA. RP McCleese, DJ (reprint author), Jet Propuls Lab, Pasadena, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MASS INST TECHNOL PI CAMBRIDGE PA TECHNOLOGY REVIEW, INC, ONE MAIN ST, 7TH FLOOR, CAMBRIDGE, MA 02142 USA SN 1099-274X J9 TECHNOL REV JI Technol. Rev. PD JAN-FEB PY 2008 VL 111 IS 1 BP 8 EP 8 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 245PR UT WOS:000251948200008 ER PT S AU Ashish, N Eguchi, R Hegde, R Huyck, C Kalashnikov, D Mehrotra, S Smyth, P Venkatasubramanian, N AF Ashish, Naveen Eguchi, Ronald Hegde, Rajesh Huyck, Charles Kalashnikov, Dmitri Mehrotra, Sharad Smyth, Padhraic Venkatasubramanian, Nalini BE Chen, H Reid, E Sinai, J Silke, A Ganor, B TI SITUATIONAL AWARENESS TECHNOLOGIES FOR DISASTER RESPONSE SO TERRORISM INFORMATICS: KNOWLEDGE MANAGEMENT AND DATA MINING FOR HOMELAND SECURITY SE Integrated Series in Information Systems LA English DT Article; Book Chapter AB This chapter highlights some of the key information technology challenges being addressed in the RESCUE project, a National Science Foundation (NSF) funded 5-year effort, with a particular focus on situational awareness technologies. A key premise of the project is that the critical decision making required in disaster situations relies heavily on the availability, accuracy, and timeliness of information that can be made available to the decision makers. A major thrust within RESCUE is focusing on developing next generation situational awareness technologies. Our approach in building situational awareness systems is to build information systems that consider situations and events as fundamental entities, and our research is focused on the key technical challenges in the extraction and synthesis, management, and analysis of such situational information. This chapter focuses on our research accomplishments in each of these areas and also provides an overview of technology transition activities. C1 [Ashish, Naveen] Univ Calif Irvine, Donald Bren Sch Informat & Comp Sci, Calit2, Irvine, CA 92717 USA. [Eguchi, Ronald; Huyck, Charles] Image Cat Inc, Long Beach, CA USA. [Hegde, Rajesh] Univ Calif San Diego, Dept Elect & Comp Engn, San Diego, CA 92103 USA. [Ashish, Naveen] NASA, Ames Res Ctr, Washington, DC USA. [Smyth, Padhraic] CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Ashish, N (reprint author), Univ Calif Irvine, Donald Bren Sch Informat & Comp Sci, Calit2, Irvine, CA 92717 USA. EM ashish@ics.uci.edu; rhegde@ucsd.edu; chk@imagecatinc.com; dvk@ics.uci.edu; sharad@ics.uci.edu; smyth@ics.uci.edu; nalini@ics.uci.edu NR 20 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES SN 1571-0270 BN 978-0-387-71613-8 J9 INTEGR SER INFORM SY PY 2008 VL 18 BP 517 EP 544 D2 10.1007/978-0-387-71613-8 PG 28 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Information Science & Library Science; Political Science SC Computer Science; Information Science & Library Science; Government & Law GA BLM35 UT WOS:000270526000025 ER PT S AU Havelund, K AF Havelund, Klaus BE Suzuki, K Higashino, T Ulrich, A Hasegawa, T TI Runtime verification of C programs SO TESTING OF SOFTWARE AND COMMUNICATING SYSTEMS, PROCEEDINGS SE Lecture Notes in Computer Science LA English DT Proceedings Paper CT International Conference on Testing of Software and Communicating Systems CY JUN 10-13, 2008 CL Tokyo, JAPAN SP IFIP TC 6 WG 6 1 AB We present in this paper a framework, RmOR, for monitoring the execution of C programs against state machines, expressed in a textual (non-graphical) format in files separate from the program. The state machine language has been inspired by a graphical state machine language RCAT recently developed at the Jet Propulsion Laboratory, as an alternative to using Linear Temporal Logic (LTL) for requirements capture. Transitions between states are labeled with abstract event names and Boolean expressions over such. The abstract events are connected to code fragments using an aspect-oriented pointcut language similar to ASPECTJ'S or AsPECTC'S pointcut language. The system is implemented in the C analysis and transformation package CIL, and is programmed in OCAML, the implementation language Of CIL. The work is closely related to the notion of stateful aspects within aspect-oriented programming, where pointcut languages are extended with temporal assertions over the execution trace. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Havelund, K (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Klaus.Havelund@jpl.nasa.gov NR 27 TC 19 Z9 19 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 978-3-540-68514-2 J9 LECT NOTES COMPUT SC PY 2008 VL 5047 BP 7 EP 22 PG 16 WC Computer Science, Software Engineering; Computer Science, Theory & Methods; Telecommunications SC Computer Science; Telecommunications GA BHU74 UT WOS:000256543900003 ER PT S AU Markley, FL AF Markley, F. Landis BE Crassidis, JL Junkins, JL Howell, KC Oshman, Y Thienel, JK TI LESSONS LEARNED SO THE F. LANDIS MARKLEY ASTRONAUTICS SYMPOSIUM SE Advances in the Astronautical Sciences LA English DT Proceedings Paper CT F Landis Markley Astronautics Symposium CY JUN 29-JUL 02, 2008 CL Cambridge, MD SP Amer Astronaut Soc, Univ Buffalo, Hubble Space Telescope Project, Comp Sci Corp, General Dynam, John Hopkins Univ, Appl Phys Lab, Spacecraft Syst Engn Serv, Amer Inst Aeronaut & Astronaut, Baltimore Sect ID SPACECRAFT ATTITUDE ESTIMATION; VECTOR OBSERVATIONS; QUATERNION; REPRESENTATIONS; CONSTRAINT; ESTIMATOR; ALGORITHM; MOMENTUM; DYNAMICS; FILTER AB This paper is organized around three themes that have interested me over my career: covariance analysis, constrained estimation, and angular momentum. Both analytical and numerical approaches to covariance analysis are discussed. The section on constraints begins with general considerations arising from the nature of the rotation group before moving to Wahba's Problem and quaternion Kalman filters. The discussion of angular momentum includes its use in attitude determination and control as well as in the detection and diagnosis of spacecraft anomalies. Relevant illustrative examples are included. C1 NASA, Goddard Space Flight Ctr, Nav & Control Syst Engn Branch, Greenbelt, MD 20771 USA. RP Markley, FL (reprint author), NASA, Goddard Space Flight Ctr, Nav & Control Syst Engn Branch, Code 591, Greenbelt, MD 20771 USA. EM landis.markley@nasa.gov NR 48 TC 0 Z9 0 U1 0 U2 0 PU AMER ASTRONAUTICAL SOC PI SAN DIEGO PA PUBLICATIONS OFFICE PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-548-0 J9 ADV ASTRONAUT SCI PY 2008 VL 132 BP 3 EP 22 PG 20 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIY15 UT WOS:000263678000001 ER PT S AU Carpenter, JR Markley, FL AF Carpenter, J. Russell Markley, F. Landis BE Crassidis, JL Junkins, JL Howell, KC Oshman, Y Thienel, JK TI GENERALIZED LINEAR COVARIANCE ANALYSIS SO THE F. LANDIS MARKLEY ASTRONAUTICS SYMPOSIUM SE Advances in the Astronautical Sciences LA English DT Proceedings Paper CT F Landis Markley Astronautics Symposium CY JUN 29-JUL 02, 2008 CL Cambridge, MD SP Amer Astronaut Soc, Univ Buffalo, Hubble Space Telescope Project, Comp Sci Corp, General Dynam, John Hopkins Univ, Appl Phys Lab, Spacecraft Syst Engn Serv, Amer Inst Aeronaut & Astronaut, Baltimore Sect AB We review and extend in two directions the results of prior work on generalized covariance analysis methods. This prior work allowed for partitioning of the state space into "solve-for" and "consider" parameters, allowed for differences between the formal values and the true values of the measurement noise, process noise, and a priori solve-for and consider covariances, and explicitly partitioned the errors into subspaces containing only the influence of the measurement noise, process noise, and a priori solve-for and consider covariances. In this work, we explicitly add sensitivity analysis to this prior work, and relax an implicit assumption that the batch estimator's anchor time occurs prior to the definitive span, We also apply the method to an integrated orbit and attitude problem, in which gyro and accelerometer errors, though not estimated, influence the orbit determination performance. We illustrate our results using two graphical presentations, which we call the "variance sandpile" and the "sensitivity mosaic," and we compare the linear covariance results to confidence intervals associated with ensemble statistics from a Monte Carlo analysis. C1 [Carpenter, J. Russell] NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 USA. RP Carpenter, JR (reprint author), NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Code 595, Greenbelt, MD 20771 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU AMER ASTRONAUTICAL SOC PI SAN DIEGO PA PUBLICATIONS OFFICE PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-548-0 J9 ADV ASTRONAUT SCI PY 2008 VL 132 BP 217 EP 241 PG 25 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIY15 UT WOS:000263678000014 ER PT S AU Burns, RD Naasz, BJ Queen, SZ Van Eepoel, J Hannah, J Skelton, E AF Burns, Richard D. Naasz, Bo J. Queen, Steven Z. Van Eepoel, John Hannah, Joel Skelton, Eugene BE Crassidis, JL Junkins, JL Howell, KC Oshman, Y Thienel, JK TI THE HST SM4 RELATIVE NAVIGATION SENSOR SYSTEM: OVERVIEW AND PRELIMINARY TESTING RESULTS FROM THE FLIGHT ROBOTICS LAB SO THE F. LANDIS MARKLEY ASTRONAUTICS SYMPOSIUM SE Advances in the Astronautical Sciences LA English DT Proceedings Paper CT F Landis Markley Astronautics Symposium CY JUN 29-JUL 02, 2008 CL Cambridge, MD SP Amer Astronaut Soc, Univ Buffalo, Hubble Space Telescope Project, Comp Sci Corp, General Dynam, John Hopkins Univ, Appl Phys Lab, Spacecraft Syst Engn Serv, Amer Inst Aeronaut & Astronaut, Baltimore Sect AB The upcoming Hubble Space Telescope (HST) Servicing Mission 4 (SM4) includes a Relative Navigation Sensor (RNS) experiment which uses three cameras and an avionics package to record images, and estimate in real-time the relative position and attitude (aka "pose") during the Shuttle capture and deployment of the telescope. RNS recently completed its third and filial phase of testing at the Marshall Space Flight Center Flight Robotics Laboratory. This testing utilized flight spare cameras, engineering development unit avionics and flight pose algorithms to estimate the pose of a Hubble mockup mounted to the Flight Robotics Laboratory (FRL) Dynamic Overhead Target Simulator (DOTS). The mockup was moved through a variety of flight-like lighting conditions and trajectories. In this paper we present pose estimation results from the third phase of RNS FRL testing. C1 [Burns, Richard D.; Naasz, Bo J.; Queen, Steven Z.; Van Eepoel, John] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Burns, RD (reprint author), NASA, Goddard Space Flight Ctr, Code 444, Greenbelt, MD 20771 USA. NR 13 TC 1 Z9 1 U1 0 U2 2 PU AMER ASTRONAUTICAL SOC PI SAN DIEGO PA PUBLICATIONS OFFICE PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-548-0 J9 ADV ASTRONAUT SCI PY 2008 VL 132 BP 351 EP 377 PG 27 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIY15 UT WOS:000263678000021 ER PT S AU Frost, SA Balas, MJ AF Frost, Susan A. Balas, Mark J. BE Crassidis, JL Junkins, JL Howell, KC Oshman, Y Thienel, JK TI ADAPTIVE KEY COMPONENT CONTROL AND INHERITANCE OF ALMOST STRICT PASSIVITY IN EVOLVING SYSTEMS SO THE F. LANDIS MARKLEY ASTRONAUTICS SYMPOSIUM SE Advances in the Astronautical Sciences LA English DT Proceedings Paper CT F Landis Markley Astronautics Symposium CY JUN 29-JUL 02, 2008 CL Cambridge, MD SP Amer Astronaut Soc, Univ Buffalo, Hubble Space Telescope Project, Comp Sci Corp, General Dynam, John Hopkins Univ, Appl Phys Lab, Spacecraft Syst Engn Serv, Amer Inst Aeronaut & Astronaut, Baltimore Sect AB The inheritance of subsystem traits in Evolving Systems is an important area of study. Evolving Systems are autonomously controlled subsystems which self-assemble into a new Evolved System with a higher purpose. Evolving Systems of aerospace structures often require additional control when assembling to maintain stability during the entire evolution process. If certain passivity traits of the subsystem components are inherited in the Evolving System, then it is possible to use an adaptive controller to restore stability in the Evolving System. We give a theorem describing conditions under which almost strict passivity is inherited in Evolving Systems. C1 [Frost, Susan A.] NASA, Ames Res Ctr, Intelligent Syst Div, Moffett Field, CA 94035 USA. RP Frost, SA (reprint author), NASA, Ames Res Ctr, Intelligent Syst Div, M-S 269-1, Moffett Field, CA 94035 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER ASTRONAUTICAL SOC PI SAN DIEGO PA PUBLICATIONS OFFICE PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-548-0 J9 ADV ASTRONAUT SCI PY 2008 VL 132 BP 575 EP 584 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIY15 UT WOS:000263678000033 ER PT S AU Hanak, C Zanetti, R AF Hanak, Chad Zanetti, Renato BE Crassidis, JL Junkins, JL Howell, KC Oshman, Y Thienel, JK TI RELATIVE NAVIGATION FOR THE ORION VEHICLE SO THE F. LANDIS MARKLEY ASTRONAUTICS SYMPOSIUM SE Advances in the Astronautical Sciences LA English DT Proceedings Paper CT F Landis Markley Astronautics Symposium CY JUN 29-JUL 02, 2008 CL Cambridge, MD SP Amer Astronaut Soc, Univ Buffalo, Hubble Space Telescope Project, Comp Sci Corp, General Dynam, John Hopkins Univ, Appl Phys Lab, Spacecraft Syst Engn Serv, Amer Inst Aeronaut & Astronaut, Baltimore Sect AB The Orion vehicle is being designed to provide manned spaceflight capability after the retirement of the Space Shuttle in 2010. Orion will provide access to both the International Space Station and the Moon. In both cases, the vehicle is required to perform rendezvous and therefore requires a relative navigation filter. This paper documents the preliminary analysis performed by the Orion Navigation team, and reviews the current Orion relative navigation architecture as well as the sensors available for rendezvous and proximity operations. C1 [Hanak, Chad] NASA, Lyndon B Johnson Space Ctr, Aerosci & Flight Mech Div, Houston, TX 77058 USA. RP Hanak, C (reprint author), NASA, Lyndon B Johnson Space Ctr, Aerosci & Flight Mech Div, NASA JSC EG6,2101 NASA Pkwy, Houston, TX 77058 USA. EM chad.hanak-1@nasa.gov; rzanetti@draper.com NR 4 TC 2 Z9 2 U1 0 U2 1 PU AMER ASTRONAUTICAL SOC PI SAN DIEGO PA PUBLICATIONS OFFICE PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-548-0 J9 ADV ASTRONAUT SCI PY 2008 VL 132 BP 793 EP 811 PG 19 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIY15 UT WOS:000263678000045 ER PT S AU Wood, LJ AF Wood, Lincoln J. BE Crassidis, JL Junkins, JL Howell, KC Oshman, Y Thienel, JK TI THE EVOLUTION OF DEEP SPACE NAVIGATION: 1989-1999 SO THE F. LANDIS MARKLEY ASTRONAUTICS SYMPOSIUM SE Advances in the Astronautical Sciences LA English DT Proceedings Paper CT F Landis Markley Astronautics Symposium CY JUN 29-JUL 02, 2008 CL Cambridge, MD SP Amer Astronaut Soc, Univ Buffalo, Hubble Space Telescope Project, Comp Sci Corp, General Dynam, John Hopkins Univ, Appl Phys Lab, Spacecraft Syst Engn Serv, Amer Inst Aeronaut & Astronaut, Baltimore Sect ID MARS GLOBAL SURVEYOR; GALILEO ORBIT DETERMINATION; ASTEROID 253 MATHILDE; PRIME MISSION; AEROBRAKING; DESIGN; ENCOUNTER; MAGELLAN; PATHFINDER; OPERATIONS AB The exploration of the planets of the solar system using robotic vehicles has been underway since the early 1960s. During this time the navigational capabilities employed have increased greatly in accuracy, as required by the scientific objectives of the missions and as enabled by improvements in technology. This paper is the second in a chronological sequence dealing with the evolution of deep space navigation. The time interval covered extends from the 1989 launch of the Magellan spacecraft to Venus through a multiplicity of planetary exploration activities in 1999. The paper focuses on the observational techniques that have been used to obtain navigational information, propellant-efficient means for modifying spacecraft trajectories, and the computational methods that have been employed, tracing their evolution through a dozen planetary missions. C1 CALTECH, Jet Prop Lab, Nav & Control Sect, Pasadena, CA 91109 USA. RP Wood, LJ (reprint author), CALTECH, Jet Prop Lab, Nav & Control Sect, Mail Stop 301-150,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Lincoln.J.Wood@jpl.nasa.gov NR 69 TC 2 Z9 2 U1 0 U2 0 PU AMER ASTRONAUTICAL SOC PI SAN DIEGO PA PUBLICATIONS OFFICE PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 978-0-87703-548-0 J9 ADV ASTRONAUT SCI PY 2008 VL 132 BP 877 EP 898 PG 22 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BIY15 UT WOS:000263678000050 ER PT B AU Goldstein, ME AF Goldstein, M. E. BE Sohrab, SH Catrakis, HJ Benra, IFK TI The aeroacoustics of turbulent flows SO THEORETICAL AND EXPERIMENTAL ASPECTS OF FLUID MECHANICS: PROCEEDINGS OF THE 5TH WSEAS INTERNATIONAL CONFERENCE ON FLUID MECHANICS (FLUIDS '08) SE Mathematics and Computers in Science and Engineering LA English DT Proceedings Paper CT 5th International Conference on Fluid Mechanics CY JAN 25-27, 2008 CL Acapulco, MEXICO SP WSEAS DE aeroacoustics; jet noise; turbulence; aerodynamic sound; turbulent flow ID JET NOISE AB Aerodynamic noise prediction has been an important and challenging research area since James Lighthill first introduced his Acoustic Analogy Approach over fifty years ago. This talk attempts to provide a unified framework for the subsequent theoretical developments in this field. It assumes that there is no single approach that is optimal in all situations and uses the framework as a basis for discussing the strengths weaknesses of the various approaches to this topic. But the emphasis here will be on the important problem of predicting the noise from high speed air jets. Specific results will presented for round jets in the 0.5 to 1.4 Mach number range and compared with experimental data taken on the Glenn SHAR rig. It is demonstrated that non-parallel mean flow effects play an important role in predicting the noise at the supersonic Mach numbers. The results explain the failure of previous attempts based on the parallel flow Lilley model (which has served as the foundation for most jet noise analyses during past two decades). C1 NASA, Glenn Res Ctr, Res & Technol Directorate, Cleveland, OH 44135 USA. RP Goldstein, ME (reprint author), NASA, Glenn Res Ctr, Res & Technol Directorate, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC AND ENGINEERING ACAD AND SOC PI ATHENS PA AG LOANNOU THEOLOGOU 17-23, 15773 ZOGRAPHOU, ATHENS, GREECE BN 978-960-6766-30-5 J9 MA COMPUT SCI ENG PY 2008 BP 168 EP 181 PG 14 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BHL18 UT WOS:000254015800023 ER PT S AU Daryabeigi, K Cunnington, GR Knutson, JR AF Daryabeigi, K. Cunnington, G. R. Knutson, J. R. BE Koenig, JR Ban, H TI Measurement of Heat Transfer in Unbonded Silica Fibrous Insulation and Comparison with Theory SO THERMAL CONDUCTIVITY 29: THERMAL EXPANSION 17 SE THERMAL CONDUCTIVITY LA English DT Proceedings Paper CT Joint 29th International Thermal Conductivity Conference/17th International Thermal Expansion Symposium CY JUN 24-27, 2007 CL SE Res Inst, Birmingham, AL SP Univ Alabama Birmingham HO SE Res Inst ID CONDUCTION; RADIATION; MODELS; MEDIA AB Effective thermal conductivity of a high porosity unbonded silica fibrous insulation specimen was measured over a pressure range of 0.001 to 750 torr (0.1 to 101.3 x 10(3) Pa), and with large temperature gradients maintained across the sample thickness: hot side temperature range of 530 to 1360 K, with the cold side at room temperature. The measurements were compared with the theoretical solution of combined radiation/conduction heat transfer. The previously developed radiation heat transfer model used in this study is based on a modified diffusion approximation, and uses deterministic parameters that define the composition and morphology of the medium: distributions of fiber size and orientation, fiber volume fractions, and the spectral complex refractive index of the fibers. The close agreement between experimental and theoretical data further verifies the theoretical model over a wide range of temperatures and pressures. C1 [Daryabeigi, K.; Knutson, J. R.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Daryabeigi, K (reprint author), NASA, Langley Res Ctr, MS 190, Hampton, VA 23681 USA. NR 25 TC 2 Z9 2 U1 0 U2 3 PU DESTECH PUBLICATIONS, INC PI LANCASTER PA 439 DUKE STREET, LANCASTER, PA 17602-4967 USA SN 0163-9005 BN 978-1-932078-72-5 J9 THERM COND PY 2008 VL 29 BP 292 EP 301 PG 10 WC Thermodynamics; Materials Science, Multidisciplinary; Physics, Applied SC Thermodynamics; Materials Science; Physics GA BIT68 UT WOS:000262630300025 ER PT S AU Fesmire, JE Augustynowicz, SD Scholtens, BE Heckle, KW AF Fesmire, J. E. Augustynowicz, S. D. Scholtens, B. E. Heckle, K. W. BE Koenig, JR Ban, H TI Thermal Performance Testing of Cryogenic Insulation Systems SO THERMAL CONDUCTIVITY 29: THERMAL EXPANSION 17 SE THERMAL CONDUCTIVITY LA English DT Proceedings Paper CT Joint 29th International Thermal Conductivity Conference/17th International Thermal Expansion Symposium CY JUN 24-27, 2007 CL SE Res Inst, Birmingham, AL SP Univ Alabama Birmingham HO SE Res Inst AB Efficient ways to characterize thermal performance or materials under cryogenic and vacuum conditions have been developed. These methods provide thermal conductivity data on materials under actual-use conditions and complement established methods. The actual-use environment of a large temperature difference across the insulation in combination with vacuum pressure is essential For understanding how insulation systems perform. Test articles include solids, foams, powders, layered blankets, and composite panels. Test methodology and apparatus design for several insulation test cryostats are discussed. The measurement principle is liquid nitrogen boiloff calorimetry. Heat flux capability ranges from about 0.5 to 500 whil 2; corresponding apparent thermal conductivity values range from below 0.01 up to about 60 mW/m-K. Example data for different insulation materials are also presented. After Further work to standardize test methods, these patented insulation test cryostats can be used in a wide range of industrial applications. C1 [Fesmire, J. E.; Scholtens, B. E.] NASA, Cryogen Test Lab, KT E, Kennedy Space Ctr, FL 32899 USA. RP Fesmire, JE (reprint author), NASA, Cryogen Test Lab, KT E, Kennedy Space Ctr, FL 32899 USA. NR 21 TC 10 Z9 10 U1 0 U2 2 PU DESTECH PUBLICATIONS, INC PI LANCASTER PA 439 DUKE STREET, LANCASTER, PA 17602-4967 USA SN 0163-9005 BN 978-1-932078-72-5 J9 THERM COND PY 2008 VL 29 BP 387 EP 396 PG 10 WC Thermodynamics; Materials Science, Multidisciplinary; Physics, Applied SC Thermodynamics; Materials Science; Physics GA BIT68 UT WOS:000262630300033 ER PT S AU Ohilhorst, CW Vaughn, WL Daryabeigi, K Lewis, RK Rodriguez, AC Milhoan, JD Koenig, JR AF Ohilhorst, C. W. Vaughn, W. L. Daryabeigi, K. Lewis, R. K. Rodriguez, A. C. Milhoan, J. D. Koenig, J. R. BE Koenig, JR Ban, H TI Emissivity Results on High Temperature Coatings for Refractory Composite Materials SO THERMAL CONDUCTIVITY 29: THERMAL EXPANSION 17 SE THERMAL CONDUCTIVITY LA English DT Proceedings Paper CT Joint 29th International Thermal Conductivity Conference/17th International Thermal Expansion Symposium CY JUN 24-27, 2007 CL SE Res Inst, Birmingham, AL SP Univ Alabama Birmingham HO SE Res Inst AB The directional emissivity of various refractory composite materials considered for application for reentry and hypersonic vehicles was investigated. The directional emissivity was measured at elevated temperatures of up to 3400 degrees F using a directional spectral radiometric technique during arc-jet test runs. A laboratory-based relative total radiance method was also used to measure total normal emissivity of some of the refractory composite materials. The data from the two techniques are compared. The paper will also compare the historical database of Reinforced Carbon-Carbon emissivity measurements with emissivity values generated recently on the material using the two techniques described in the paper. C1 [Ohilhorst, C. W.; Vaughn, W. L.; Daryabeigi, K.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Ohilhorst, CW (reprint author), NASA, Langley Res Ctr, MS 188A, Hampton, VA 23681 USA. NR 7 TC 1 Z9 1 U1 0 U2 4 PU DESTECH PUBLICATIONS, INC PI LANCASTER PA 439 DUKE STREET, LANCASTER, PA 17602-4967 USA SN 0163-9005 BN 978-1-932078-72-5 J9 THERM COND PY 2008 VL 29 BP 535 EP 547 PG 13 WC Thermodynamics; Materials Science, Multidisciplinary; Physics, Applied SC Thermodynamics; Materials Science; Physics GA BIT68 UT WOS:000262630300046 ER PT S AU Lu, T Yin, S Zhang, JZ Li, JG Wu, F AF Lu, Thomas Yin, Stuart Zhang, Jianzhong Li, Jiangan Wu, Frank BE Corner, BD Mochimaru, M Sitnik, R TI Rapid 360 degree imaging and stitching 3D objects using multiple precision 3D cameras SO THREE-DIMENSIONAL IMAGE CAPTURE AND APPLICATIONS 2008 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Three-Dimensional Image Capture and Applications 2008 CY JAN 28-29, 2008 CL San Jose, CA SP SPIE, IS&T, Soc Imaging Sci & Technol DE 3D imaging; digital camera; high resolution; 360 degree; precision 3D model ID STRUCTURED LIGHT; VISION AB In this paper, we present the system architecture of a 360 degree view 3D imaging system. The system consists of multiple 3D sensors synchronized to take 3D images around the object. Each 3D camera employs a single high-resolution digital camera and a color-coded light projector. The cameras are synchronized to rapidly capture the 3D and color information of a static object or a live person. The color-encoded structure lighting ensures the precise reconstruction of the depth of the object. A 3D imaging system architecture is presented. The architecture employs the displacement of the camera and the projector to triangulate the depth information. The 3D camera system has achieved high depth resolution down to 0.1mm on a human head sized object and 360 degree imaging capability. C1 [Lu, Thomas] CalTech, JPL, Pasadena, CA USA. RP Lu, T (reprint author), CalTech, JPL, Pasadena, CA USA. NR 18 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6977-9 J9 PROC SPIE PY 2008 VL 6805 AR 680506 PG 10 WC Computer Science, Software Engineering; Optics SC Computer Science; Optics GA BHR56 UT WOS:000255679800005 ER PT B AU Rogers, JR Hyers, RW AF Rogers, Jan R. Hyers, Robert W. GP TMS TI Electrostatic levitation: An emerging materials characterization technique SO TMS 2008 ANNUAL MEETING SUPPLEMENTAL PROCEEDINGS, VOL 2: MATERIALS CHARACTERIZATION, COMPUTATION AND MODELING LA English DT Proceedings Paper CT 137th Annual Meeting and Exhibition of the Minerals-Metals-and-Materials-Society CY MAR 09-13, 2008 CL New Orleans, LA DE levitation; thermophysical properties; emissivity; high-temperature characterization AB Electrostatic levitation (ESL) uses electrostatic fields to position samples between electrodes during processing and characterization studies. Because the samples float between the electrodes during studies, they are free from any contact with a container or test apparatus. This provides a high purity environment for the study of high-temperature (up to 3400 degrees C), reactive materials, as well as access to deeply undercooled melts and metastable states. ESL can be used to process a wide variety of materials including metals, alloys, ceramics, glasses and semiconductors. Apparatus and techniques have been developed to use this technique to provide data for phase diagram determination, creep resistance, emissivity, specific heat, density/thermal expansion, viscosity, surface tension and triggered nucleation of melts. Scientific topics investigated using ESL include phase selection and the formation of quasicrystals and bulk metallic glasses. Results from selected ESL-based characterization studies performed at NASA's Marshall Space Flight Center will be presented. C1 [Rogers, Jan R.] NASA, Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Rogers, JR (reprint author), NASA, Marshall Space Flight Ctr, Mail Code EM50, Huntsville, AL 35812 USA. RI Hyers, Robert/G-3755-2010 NR 16 TC 0 Z9 0 U1 0 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 978-0-87339-717-9 PY 2008 BP 9 EP 14 PG 6 WC Computer Science, Interdisciplinary Applications; Mathematics, Applied; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Computer Science; Mathematics; Metallurgy & Metallurgical Engineering; Materials Science GA BHQ99 UT WOS:000255585000002 ER PT J AU Miyoshi, K Jeffrey, HSB Hager, CH Zabinski, JS Wal, RLV Andrews, R Street, KW Lerch, BA Abel, PB AF Miyoshi, Kazuhisa Sanders, Jeffrey H. Hager, Carl H., Jr. Zabinski, Jeffrey S. Wal, Randall L. Vander Andrews, Rodney Street, Kenneth W. Lerch, Bradley A. Abel, Phillip B. TI Wear behavior of low-cost, lightweight TiC/Ti-6Al-4V composite under fretting: Effectiveness of solid-film lubricant counterparts SO TRIBOLOGY INTERNATIONAL LA English DT Article DE fretting wear; TiC/Ti-6Al-4V; anti-galling coatings ID FATIGUE AB The wear behavior of low-cost, lightweight 10 wt% titanium carbide (TiC)-particulate-reinforced Ti-6Al-4V matrix composite (TiC/Ti-6Al-4V) was examined under fretting at 296, 423, and 523 K in air. Bare 10 wt% TiC/Ti-6Al-4V hemispherical pins were used in contact with dispersed multiwalled carbon nanotubes (MWNTs), magnetron-sputtered diamond-like carbon/chromium (DLC/Cr), magnetron-sputtered graphite-like carbon/chromium (GLC/Cr), and magnetron-sputtered molybdenum disulfide/titanium (MoS2/Ti) deposited on Ti-6Al-4V, Ti-48Al-2Cr-2Nb, and nickel-based superalloy 718. When TiC/Ti-6Al-4V was brought into contact with bare Ti-6Al-4V, bare Ti-48Al-2Cr-2Nb, and bare nickel-based superalloy 718, strong adhesion, severe galling, and severe wear occurred. However, when TiC/Ti-6Al-4V was brought into contact with MWNT, DLC/Cr, GLC/Cr, and MoS2,/Ti coatings, no galling occurred in the contact, and relatively minor wear was observed regardless of the coating. All the MWNT, DLC/Cr, GLC/Cr, and MoS2/Ti coatings on Ti-6Al-4V were effective from 296 to 523 K, but the effectiveness of the MWNT, DLC/Cr, GLC/Cr, and MoS2/Ti coatings decreased as temperature increased. Published by Elsevier Ltd. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. USAF, Wright Patterson AFB, OH 45433 USA. Natl Ctr Space Explorat Res, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Kentucky, Lexington, KY 40511 USA. RP Miyoshi, K (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Kazuhisa.Miyoshi@nasa.gov NR 20 TC 11 Z9 11 U1 0 U2 11 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0301-679X J9 TRIBOL INT JI Tribol. Int. PD JAN PY 2008 VL 41 IS 1 BP 24 EP 33 DI 10.1016/j.triboint.2007.04.006 PG 10 WC Engineering, Mechanical SC Engineering GA 222CU UT WOS:000250274500004 ER PT J AU Zaretsky, EV Lewicki, DG Savage, M Vlcek, BL AF Zaretsky, Erwin V. Lewicki, David G. Savage, Michael Vlcek, Brian L. TI Determination of turboprop reduction gearbox system fatigue life and reliability SO TRIBOLOGY & LUBRICATION TECHNOLOGY LA English DT Article DE gearbox life prediction; gearing; rolling-element bearings; Monte-Carlo analysis; probabilistic life analysis; weibull analysis ID SPUR AB Two computational models to determine the fatigue life and reliability of a commercial turboprop gearbox are compared with each other and with field data. These models are (1.) Monte Carlo simulation of randomly selected lives of individual bearings and gears comprising the system and (2.) two-parameter Weibull distribution function for bearings and gears comprising the system using strict-series system reliability to combine the calculated individual component lives in the gearbox. The Monte Carlo simulation included the virtual testing of 744,450 gearboxes. Two sets of field data were obtained from 64 gearboxes that were first-run to removal for cause, were refurbished and placed back in service, and then were second-run until removal for cause. A series of equations were empirically developed from the Monte Carlo simulation to determine the statistical variation in predicted life and Weibull slope as a function of the number of gearboxes failed. The resultant L-10 life from the field data was 5,627 h. From strict-series system reliability, the predicted L-10 life was 774 h. From the Monte Carlo simulation, the median value for the L-10 gearbox lives equaled 757 h. Half of the gearbox L-10 lives will be less than this value and the other half more. The resultant L10 life of the second-run (refurbished) gearboxes was 1,334 h. The apparent load-life exponent p for the roller bearings is 5.2. Were the bearing lives to be recalculated with a load-life exponent p equal to 5.2, the predicted L-10 life of the gearbox would be equal to the actual life obtained in the field. The component failure distribution of the gearbox from the Monte Carlo simulation was nearly identical to that using the strict-series system reliability analysis, proving the compatibility of these methods. C1 [Zaretsky, Erwin V.] NASA, Glenn Res Ctr, Cleveland, OH USA. [Lewicki, David G.] US Army Res Lab, Glenn Res Ctr, Cleveland, OH USA. [Savage, Michael] Univ Akron, Akron, OH 44325 USA. [Vlcek, Brian L.] Georgia So Univ, Statesboro, GA 30460 USA. RP Zaretsky, EV (reprint author), NASA, Glenn Res Ctr, Cleveland, OH USA. NR 29 TC 0 Z9 1 U1 1 U2 4 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1545-858X J9 TRIBOL LUBR TECHNOL JI Tribol. Lubr. Technol. PD JAN PY 2008 VL 64 IS 1 BP 40 EP 50 PG 11 WC Engineering, Mechanical SC Engineering GA 249NR UT WOS:000252236000012 ER PT J AU Ene, NM Dimofte, F Keith, TG AF Ene, Nicoleta M. Dimofte, Florin Keith, Theo G. TI A Dynamic Analysis of Hydrodynamic Wave Journal Bearings SO TRIBOLOGY TRANSACTIONS LA English DT Article DE Wave Bearing; Dynamic Stability; Transient Analysis ID COEFFICIENTS; LUBRICATION; STABILITY; BEHAVIOR AB The purpose of this paper is to study the dynamic behavior of a three-wave journal bearing using a transient approach. The transient analysis permits the determination of the rotor behavior after the fractional frequency whirl appears. The journal trajectory is determined by solving a set of nonlinear equations of motion using the Runge-Katta method. The fluid film forces are computed by integrating the transient Reynolds equation at each time step location of the shaft with respect to the bearing. Because of the large values of the rotational speeds, turbulent effects were included in the computations. The influence of the temperature on the viscosity was also considered. Numerical results were compared to experimental results obtained at the NASA Glenn Research Center. Comparisons of the theoretical results with experimental data were found to be in good agreement. The numerical and experimental results showed that the fluid film of a three-wave journal bearing having a diameter of 30 mm, a length of 27 mm, and a wave amplitude ratio greater than 0.15 is stable even at rotational speeds of 60,000 RPM. For lower wave amplitude ratios, the threshold speed at which the fluid film becomes unstable depends on the wave amplitude and on the supply pocket pressure. Even if the fluid film is unstable, the wave bearing maintains the whirl orbit inside the bearing clearance. C1 [Ene, Nicoleta M.; Keith, Theo G.] Univ Toledo, Toledo, OH 43606 USA. [Dimofte, Florin] Univ Toledo, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Ene, NM (reprint author), Univ Toledo, 2801 W Bancroft St, Toledo, OH 43606 USA. NR 31 TC 5 Z9 6 U1 0 U2 7 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PY 2008 VL 51 IS 1 BP 82 EP 91 DI 10.1080/10402000701741194 PG 10 WC Engineering, Mechanical SC Engineering GA 384FK UT WOS:000261730500006 ER PT J AU Zaretsky, EV Poplawski, JV Root, LE AF Zaretsky, Erwin V. Poplawski, Joseph V. Root, Lawrence E. TI Relation between Hertz stress-life exponent, ball-race conformity, and ball bearing life SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 61st Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY MAY 07-11, 2006 CL Calgary, CANADA SP Soc Tribologists & Lubricat Engineers DE rolling-element bearings; bearing life; race conformity; bearing geometry; stress-life exponent AB ANSI/ABMA and ISO standards based on the Lundberg-Palmgren bearing life theory are normalized for ball bearings having inner- and outer-race conformities of 52% (0.52) and made from pre-1940 bearing steel. The Lundberg-Palmgren theory incorporates an inverse 9th power relation between the Hertz stress and fatigue life for ball bearings. The effect of race conformity on the ball set life independent of the race life is not incorporated into the Lundberg-Palmgren theory. In addition, the post-1960 vacuum-processed bearing steel exhibits a 12th power relation between the Hertz stress and life. The work reported extends the previous work of Zaretsky, Poplawski, and Root to calculate the changes in bearing life - that includes the life of the ball set - caused by race conformity, the Hertz stress-life exponent, the ball bearing type, and the bearing series. The bearing fatigue life in actual application will usually be equal to or greater than that calculated using the ANSI/ABMA and ISO standards that incorporate the Lundberg-Palmgren theory. The relative fatigue life of an individual race is more sensitive to the changes in race conformity for the Hertz stress-life exponent n of 12 than where n = 9. However, when the effects are combined to predict the actual bearing life for a specified set of conditions and bearing geometry, the predicted life of the bearing will be greater for a value of n = 12 than n = 9. C1 [Zaretsky, Erwin V.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Poplawski, Joseph V.] JV Poplawski & Associates, Bethlehem, PA 18018 USA. [Root, Lawrence E.] Lawrence E Root PE, Lebanon, NH 03766 USA. RP Zaretsky, EV (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 15 TC 4 Z9 6 U1 1 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PY 2008 VL 51 IS 2 BP 150 EP 159 DI 10.1080/10402000801926380 PG 10 WC Engineering, Mechanical SC Engineering GA 283QE UT WOS:000254650800004 ER PT J AU Oswald, FB Jett, TR Predmore, RE Zaretsky, EV AF Oswald, Fred B. Jett, Timothy R. Predmore, Roamer E. Zaretsky, Erwin V. TI Probabilistic analysis of space shuttle body flap actuator ball bearings SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 62nd Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY MAY 06-10, 2007 CL Philadelphia, PA SP Soc Tribologists & Lubricat Engineers DE statistical analysis; Weibull analysis; life prediction methods; wear; ball bearings; grease lubrication AB A probabilistic analysis, using the two-parameter Weibull-Johnson method, was performed on experimental life test data from space shuttle actuator bearings. Experiments were performed on a test rig under simulated conditions to determine the life and failure mechanism of the grease lubricated bearings that support the input shaft of the space shuttle body flap actuators. The failure mechanism was wear that can cause loss of bearing preload. These tests established life and reliability data for both shuttle flight and ground operation. Test data were used to estimate the failure rate and reliability as a function of the number of shuttle missions flown. The Weibull analysis of the test data for the four actuators on one shuttle, each with a two-bearing shaft assembly, established a reliability level of 96.9% for a life of 12 missions. A probabilistic system analysis for four shuttles, each of which has four actuators, predicts a single bearing failure in one actuator of one shuttle after 22 missions (a total of 88 missions for a four-shuttle fleet). This prediction is comparable with actual shuttle flight history in which a single actuator bearing was found to have failed by wear at 20 missions. C1 [Oswald, Fred B.; Zaretsky, Erwin V.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Jett, Timothy R.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Predmore, Roamer E.] Swales Aerosp, Greenbelt, MD 20771 USA. RP Oswald, FB (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 20 TC 5 Z9 5 U1 0 U2 1 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PY 2008 VL 51 IS 2 BP 193 EP 203 DI 10.1080/10402000701732284 PG 11 WC Engineering, Mechanical SC Engineering GA 283QE UT WOS:000254650800010 ER PT J AU Dellacorte, C Radil, KC Bruckner, RJ Howard, SA AF Dellacorte, Christopher Radil, Kevin C. Bruckner, Robert J. Howard, S. Adam TI Design, fabrication, and performance of open source generation I and II compliant hydrodynamic gas foil bearings SO TRIBOLOGY TRANSACTIONS LA English DT Article DE foil bearings; fluid film bearings; turbines ID OIL-FREE TURBOMACHINERY; AIR BEARINGS AB Foil gas bearings are self-acting hydrodynamic bearings made from sheet metal foils comprised of at least two layers. The innermost top foil layer traps a gas pressure film that supports a load while a layer or layers underneath provide an elastic foundation. Foil bearings are used in many lightly loaded, high-speed turbomachines such as compressors used for aircraft pressurization and small microturbines. Foil gas bearings provide a means to eliminate the oil system leading to reduced weight and enhanced temperature capability. The general lack of familiarity of the foil bearing design and manufacturing process has hindered their widespread dissemination. This paper reviews the publicly available literature to demonstrate the design, fabrication, and performance testing of both first- and second-generation bump-style foil bearings. It is anticipated that this paper may serve as an effective starting point for new development activities employing foil bearing technology. C1 [Dellacorte, Christopher; Bruckner, Robert J.; Howard, S. Adam] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Radil, Kevin C.] USA, Res Lab, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Dellacorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 37 TC 40 Z9 42 U1 1 U2 10 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PY 2008 VL 51 IS 3 BP 254 EP 264 DI 10.1080/10402000701772579 PG 11 WC Engineering, Mechanical SC Engineering GA 317ZD UT WOS:000257058100002 ER PT J AU Pepper, SV AF Pepper, Stephen V. TI Ultra Starvation Studied in the Spiral Orbit Tribometer SO TRIBOLOGY TRANSACTIONS LA English DT Article DE Ball Bearings; Starvation in EHL; Boundary Lubrication Friction; Boundary Lubrication Chemistry; Friction Test Methods AB Spiral orbit tribometry has been used to study the coefficient of friction and electrical contact resistance of two vacuum lubricants in both the flooded system and the regime in which only a few nanoliters ( g) of the lubricant are present, and the latter regime is designated here as ultrastarved. The experiment was supported by the extension to the ultrastarved regime of the recent analysis by Cann and coworkers of contact film thickness as a function of the lubricant volume in the heavily starved regime. The coefficients of friction in the ultrastarved regime were found to be the same as for the flooded system. The contact resistance was found to be zero at the beginning of the tests in the ultrastarved regime. The analysis by Cann and coworkers predicts the absence of a mobile liquid film at the contact in the ultrastarved regime. It is speculated that this persistence of lubrication into the ultrastarved regime is due to the retention of adherent lubricant molecules on the contacting surfaces and the sliding of these molecules over each other. An incomplete coverage of these molecules permits zero contact resistance at the start of the test. The results indicate that ball bearings can operate normally in the ultrastarved regime until the lubricant is consumed by tribochemical reaction. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Pepper, SV (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 15 TC 2 Z9 2 U1 2 U2 3 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PY 2008 VL 51 IS 6 BP 723 EP 729 DI 10.1080/10402000801888929 PG 7 WC Engineering, Mechanical SC Engineering GA 361IH UT WOS:000260120800004 ER PT J AU Stanford, MK AF Stanford, Malcolm K. TI Microstructure, Physical Properties, and Tribological Characteristics of Composite Solid Lubricant Coatings with Gas Atomized BaF2-CaF2 SO TRIBOLOGY TRANSACTIONS LA English DT Article DE Adverse Environments Tribology (High Temperatures; Solid Lubricated); Aerospace Tribology; Solid Lubricants; Surface Films/Coatings (Composite) AB PS304 is a NASA-developed composite solid lubricant for friction and wear reduction at high temperatures. The microstructure, physical properties, and tribological performance of PS304 using standard comminuted BaF2-CaF2 and novel gas atomized BaF2-CaF2 were compared. Two atomized BaF2-CaF2 particle size distributions were used. Overall, feedstock powder with atomized BaF2-CaF2 flowed more freely than standard PS304 feedstock. The cohesion strength of coatings with atomized BaF2-CaF2 was lower than that of standard PS304, while the hardness of all of the studied coatings was essentially the same (approximately 58 HRA). Pin wear was lower against the new coatings and the coefficients of friction were essentially the same for all coatings. These results indicate that atomized BaF2-CaF2 can be substituted for comminuted BaF2-CaF2, providing a high-volume BaF2-CaF2 fabrication technique to reduce the cost of PS304 and improve its commercial availability. C1 NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Stanford, MK (reprint author), NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. NR 10 TC 0 Z9 0 U1 1 U2 2 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PY 2008 VL 51 IS 6 BP 829 EP 834 DI 10.1080/10402000802354079 PG 6 WC Engineering, Mechanical SC Engineering GA 506XB UT WOS:000270809700009 ER PT S AU Sibley, G Matthies, L Sukhatme, G AF Sibley, Gabe Matthies, Larry Sukhatme, Gaurav BE Kragic, D Kyrki, V TI A Sliding Window Filter for Incremental SLAM SO UNIFYING PERSPECTIVES IN COMPUTATIONAL AND ROBOT VISION SE Lecture Notes in Electrical Engineering LA English DT Article; Book Chapter C1 [Sibley, Gabe; Sukhatme, Gaurav] Univ So Calif, Robot & Embedded Syst Lab, Los Angeles, CA 90089 USA. [Sibley, Gabe; Matthies, Larry] CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Sibley, G (reprint author), Univ So Calif, Robot & Embedded Syst Lab, Los Angeles, CA 90089 USA. EM gsibley@usc.edu; lhm@jpl.nasa.gov; gaurav@usc.edu NR 10 TC 9 Z9 9 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES SN 1876-1100 BN 978-0-387-75523-6; 978-0-387-75521-2 J9 LECT NOTES ELECTR EN PY 2008 VL 8 BP 103 EP 112 D2 10.1007/978-0-387-75523-6 PG 10 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Robotics; Optics SC Computer Science; Engineering; Robotics; Optics GA BNJ41 UT WOS:000274740700008 ER PT S AU Chambers, VJ Butler, RF Goncharov, AV AF Chambers, V. J. Butler, R. F. Goncharov, A. V. BE Phelan, D Ryan, O Shearer, A TI Design of a steerable two-beam system for simultaneous on- and off-axis Imaging with GUFI SO UNIVERSE AT SUB-SECOND TIMESCALES: HIGH TIME RESOLUTION ASTROPHYSICS SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference on the Universe at Sub-Second Timescales CY SEP 11-13, 2007 CL Edinburgh, SCOTLAND SP OPTICON, Hamamatsu, Andor, ICOS DE GUFI; L3 CCD; photometry; OSLO; focal reduction ID GALACTIC STRUCTURE; STAR COUNTS AB The GUFI (Galway Ultra Fast Imager) has been primarily developed for high throughput differential photometry, in order to study variability in challenging circumstances, such as near bright sources or within crowded fields. The instrument features a low light level charged coupled device (L3-CCD) that enhances detector speed and sensitivity but only covers small fields of view. This presents limitations on possible science targets when suitable differential photometry comparison stars are not in the immediate vicinity of the target. Conventional solutions for imaging larger portions of sky without sacrificing SNR include telescope focal reduction methods and large arrays of CCDs. Our alternative solution entails a two-path, 'outrigger' optical design to image target and comparison stars separately. This new approach allows detection of variable targets that formerly were not reachable with smaller-field detectors. The mechanical design was originally generated with AutoCAD (R) drafting software before being compiled in, and vetted with an OSLO (R) optical design package. Through filters B, V and 1, the limiting design aberration was chromatic focal shift that appeared most severe in the B-filter's bandpass range. However, the degree of image blurring caused by this aberration and others did not exceed the scale of that already produced by atmospheric turbulence. For each bandpass, the model's imaging performance met and exceeded expectations set by all design constraints. C1 [Chambers, V. J.; Butler, R. F.; Goncharov, A. V.] NASA, Goddard Space Flight Ctr, Code 551,Greenbelt Rd, Greenbelt, MD 20771 USA. RP Chambers, VJ (reprint author), NASA, Goddard Space Flight Ctr, Code 551,Greenbelt Rd, Greenbelt, MD 20771 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0503-5 J9 AIP CONF PROC PY 2008 VL 984 BP 247 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BHJ61 UT WOS:000253601700027 ER PT S AU Petre, R AF Petre, R. BE Trumper, JE Hasinger, G TI X-Ray Studies of Supernovae and Supernova Remnants SO UNIVERSE IN X-RAYS SE Astronomy and Astrophysics Library LA English DT Article; Book Chapter ID LARGE-MAGELLANIC-CLOUD; XMM-NEWTON OBSERVATION; CASSIOPEIA-A; NOVA REMNANT; CYGNUS LOOP; ASCA OBSERVATIONS; LINE EMISSION; CHANDRA OBSERVATIONS; VELA-SHRAPNEL; RICH EJECTA C1 NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA. RP Petre, R (reprint author), NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA. EM robert.petre-1@nasa.gov NR 184 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES SN 0941-7834 BN 978-3-540-34411-7 J9 ASTRON ASTROPHYS LIB PY 2008 BP 261 EP 310 DI 10.1007/978-3-540-34412-4_17 D2 10.1007/978-3-540-34412-4 PG 50 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJN95 UT WOS:000266880700016 ER PT S AU Bajracharya, M Moghaddam, B Howard, A Matthies, LH AF Bajracharya, Max Moghaddam, Baback Howard, Andrew Matthies, Larry H. BE Gerhart, GR Gage, DW Shoesmaker, CM TI Detecting personnel around UGVs using stereo vision - art. no. 696202 SO UNMANNED SYSTEMS TECHNOLOGY X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unmanned Systems Technology X CY MAR 17-20, 2008 CL Orlando, FL SP SPIE DE pedestrian detection; autonomous navigation; stereo vision AB Detecting people around unmanned ground vehicles (UGVs) to facilitate safe operation of UGVs is one of the highest priority issues in the development of perception technology for autonomous navigation. Research to date has not achieved the detection ranges or reliability needed in deployed systems to detect upright pedestrians in flat, relatively uncluttered terrain, let alone in more complex environments and with people in postures that are more difficult to detect. Range data is essential to solve this problem. Combining range data with high resolution imagery may enable higher performance than range data alone because image appearance can complement shape information in range data and because cameras may offer higher angular resolution than typical range sensors. This makes stereo vision a promising approach for several reasons: image resolution is high and will continue to increase, the physical size and power dissipation of the cameras and computers will continue to decrease, and stereo cameras provide range data and imagery that are automatically spatially and temporally registered. We describe a stereo vision-based pedestrian detection system, focusing on recent improvements to a shape-based classifier applied to the range data, and present frame-level performance results that show great promise for the overall approach. C1 [Bajracharya, Max; Moghaddam, Baback; Howard, Andrew; Matthies, Larry H.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bajracharya, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 22 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7153-6 J9 P SOC PHOTO-OPT INS PY 2008 VL 6962 BP 96202 EP 96202 DI 10.1117/12.782210 PG 13 WC Robotics; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Robotics; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BHY01 UT WOS:000257316300001 ER PT S AU Liao, K Walker, MF Joshi, A Reschke, M Wang, ZO Leigh, RJ AF Liao, Ke Walker, Mark F. Joshi, Anand Reschke, Millard Wang, Zhong Leigh, R. John BE Kennard, C Leigh, RJ TI A reinterpretation of the purpose of the translational vestibulo-ocular reflex in human subjects SO USING EYE MOVEMENTS AS AN EXPERIMENTAL PROBE OF BRAIN FUNCTION - A SYMPOSIUM IN HONOR OF JEAN BUTTNER-ENNEVER SE Progress in Brain Research LA English DT Review CT Symposium on Using Eye Movements as an Experimental Probe of Brain Function held in honor of Jean Buttner Ennever CY DEC 05-06, 2007 CL Imperial College, Charing Cross Hosp Campus, London, ENGLAND HO Imperial College, Charing Cross Hosp Campus DE locomotion; vergence angle; moving platform; retinal slip ID EYE-MOVEMENT RESPONSES; MOTION; DISTANCE; TESTS AB In a prior study we reported that the human translational vestibulo-ocular reflex (tVOR) in response to vertical (bob) 2Hz oscillations generated eye rotations of only 60% of those required to keep the eyes pointed at a stationary visual target, whether located at near (similar to 17 cm) or far (2 m). Best responses occurred in ambient illumination and we concluded that relative image motion between the target and background was an important determinant of tVOR behaviour. To investigate further how visual conditions influenced tVOR, we measured responses as subjects binocularly viewed the bridge of their own nose in a mirror at similar to 8.5 cm, a visual condition that required similar convergence to viewing the near target, but cancellation of tVOR. Median tVOR cancellation gain [(near-viewing response-mirror viewing response)/near-viewing response] was 0.81 (range 0.55-0.97), which was substantially greater than the gain of smooth visual tracking of a large visual display moving at 2 Hz (median gain 0.27, range 0.09-0.42). Thus, visual inputs other than smooth tracking must contribute to tVOR cancellation. We then compared tVOR response to 2Hz bob as subjects fixed upon a visual target at 17 cm and viewed a large textured background at 1.5 m that was either stationary or moving at 2.1 Hz. Vertical eye rotations waxed and waned as a function of the difference between platform and background oscillations. These findings support our hypothesis that tVOR evolved not to stabilize the image of the target on the fovea, but rather to minimize retinal image motion between objects lying in different planes, in order to optimize motion parallax information. A geometrically based optimization function is proposed to account for tVOR responses at different target distances. C1 [Walker, Mark F.; Leigh, R. John] Case Western Reserve Univ, Dept Neurol, Daroff Dell Osso Lab, Vet Affairs Med Ctr, Cleveland, OH 44106 USA. [Liao, Ke; Walker, Mark F.; Joshi, Anand; Wang, Zhong; Leigh, R. John] Case Western Reserve Univ, Univ Hosp, Cleveland, OH 44106 USA. [Liao, Ke; Joshi, Anand; Wang, Zhong] Case Western Reserve Univ, Dept Biomed Engn, Daroff Dell Osso Lab, Vet Affairs Med Ctr, Cleveland, OH 44106 USA. [Reschke, Millard] Johnson Space Ctr, Neurosci Labs, Houston, TX USA. RP Leigh, RJ (reprint author), Case Western Reserve Univ, Dept Neurol, Daroff Dell Osso Lab, Vet Affairs Med Ctr, Cleveland, OH 44106 USA. EM rjl4@case.edu; rjl4@case.edu RI liao, ke/B-1453-2010 FU NASA/NSBRI [NA00208]; Office of Research and Development, Medical Research Service, Department of Veterans Affairs, NIH [EY06717]; Evenor Armington Fund FX This study was supported by NASA/NSBRI NA00208, Office of Research and Development, Medical Research Service, Department of Veterans Affairs, NIH grant EY06717, and the Evenor Armington Fund. We are grateful to Drs. Harold Bedell, David Zee, and Gary Paige, for their helpful advice, and to Ulrich Buttner for critical review of the manuscript. The work reported in this paper constitutes research performed by Ke Liao as part of requirements for his Doctoral Dissertation. NR 12 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0079-6123 BN 978-0-444-53163-6 J9 PROG BRAIN RES PY 2008 VL 171 BP 295 EP 302 DI 10.1016/S0079-6123(08)00643-2 PG 8 WC Neurosciences SC Neurosciences & Neurology GA BQC47 UT WOS:000280686400044 PM 18718317 ER PT S AU Croce, A Joshi, R AF Croce, Alex Joshi, Rajeev BE Logozzo, F Peled, DA Zuck, LD TI Extending model checking with dynamic analysis SO VERIFICATION, MODEL CHECKING, AND ABSTRACT INTERPRETATION SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Proceedings Paper CT 9th International Conference on Verification, Model Checking, and Abstract Interpretation CY JAN 07-09, 2008 CL San Francisco, CA SP Univ Illinois, Chicago, Microsoft AB In model-driven verification a model checker executes a program by embedding it within a test harness, thus admitting program verification without the need to translate the program, which runs as native code. Model checking techniques in which code is actually executed have recently gained popularity due to their ability to handle the full semantics of actual implementation languages and to support verification of rich properties. In this paper, we show that combination with dynamic analysis can, with relatively low overhead, considerably extend the capabilities of this style of model checking. In particular, we show how to use the CIL framework to instrument code in order to allow the SPIN model checker, when verifying C programs, to check additional properties, simulate system resets, and use local coverage information to guide the model checking search. An additional benefit of our approach is that instrumentations developed for model checking may be used without modification in testing or monitoring code. We are motivated by experience in applying model-driven verification to JPL-developed flight software modules, from which we take our example applications. We believe this is the first investigation in which an independent instrumentation for dynamic analysis has been integrated with model checking. C1 [Croce, Alex; Joshi, Rajeev] CALTECH, Jet Prop Lab, Lab Reliable Software, Pasadena, CA 91109 USA. RP Croce, A (reprint author), CALTECH, Jet Prop Lab, Lab Reliable Software, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 29 TC 1 Z9 1 U1 0 U2 2 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 978-3-540-78162-2 J9 LECT NOTES COMPUT SC PY 2008 VL 4905 BP 142 EP 156 PG 15 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BHK95 UT WOS:000253940200015 ER PT S AU Joshi, R Holzmann, GJ AF Joshi, Rajeev Holzmann, Gerard J. BE Meyer, B Woodcock, J TI A mini challenge: Build a verifiable filesystem SO VERIFIED SOFTWARE: THEORIES, TOOLS, EXPERIMENTS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Proceedings Paper CT 1st Working Conference on Verified Software - Theories, Tools and Experiments (VSTTE 2005) CY OCT 10-13, 2005 CL ETH, Zurich, SWITZERLAND SP IFIP TC 2, WG 2 3 HO ETH AB We propose tackling a "mini challenge" problem: a nontrivial verification effort that can be completed in 2-3 years, and will help establish notational standards, common formats, and libraries of benchmarks that will be essential in order for the verification community to collaborate on meeting Hoare's 15-year verification grand challenge. We believe that a suitable candidate for such a mini challenge is the development of a filesystem that is verifiably reliable and secure. The paper argues why we believe a filesystem is the right candidate for a mini challenge and describes a project in which we are building a small embedded filesystem for use with flash memory. C1 [Joshi, Rajeev; Holzmann, Gerard J.] CALTECH, Jet Prop Lab, Lab Reliable Software, Pasadena, CA 91109 USA. RP Joshi, R (reprint author), CALTECH, Jet Prop Lab, Lab Reliable Software, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 978-3-540-69147-1 J9 LECT NOTES COMPUT SC PY 2008 VL 4171 BP 49 EP 56 PG 8 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BIH10 UT WOS:000259442300006 ER PT S AU Holzmann, GJ Joshi, R AF Holzmann, Gerard J. Joshi, Rajeev BE Meyer, B Woodcock, J TI Reliable software systems design: Defect prevention, detection, and containment SO VERIFIED SOFTWARE: THEORIES, TOOLS, EXPERIMENTS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Proceedings Paper CT 1st Working Conference on Verified Software - Theories, Tools and Experiments (VSTTE 2005) CY OCT 10-13, 2005 CL ETH, Zurich, SWITZERLAND SP IFIP TC 2, WG 2 3 HO ETH AB The grand challenge that is the focus of this conference targets the development of a practical methodology for software verification: a methodology that can help us to reduce the number of residual defects in software products. Reducing residual defects is of course not in itself the objective of this exercise; the true objective is to reduce the number of failures in the use of software products. Or in other words: the objective is the development of a methodology for "reliable software systems design". C1 [Holzmann, Gerard J.; Joshi, Rajeev] CALTECH, Jet Prop Lab, Lab Reliable Software LaRS, Pasadena, CA 91109 USA. RP Holzmann, GJ (reprint author), CALTECH, Jet Prop Lab, Lab Reliable Software LaRS, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Meyer, Bertrand/E-4543-2010 OI Meyer, Bertrand/0000-0002-5985-7434 NR 7 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 978-3-540-69147-1 J9 LECT NOTES COMPUT SC PY 2008 VL 4171 BP 237 EP 244 PG 8 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BIH10 UT WOS:000259442300025 ER PT S AU Sun, S Xiang, A Shen, C Zhu, P Chao, BF AF Sun, S. Xiang, A. Shen, C. Zhu, P. Chao, B. F. BE Xu, P Liu, J Dermanis, A TI Gravity Change After the First Water Impoundment in the Three-Gorges Reservoir, China SO VI HOTINE-MARUSSI SYMPOSIUM ON THEORETICAL AND COMPUTATIONAL GEODESY SE International Association of Geodesy Symposia LA English DT Proceedings Paper CT 6th Hotine-Marussi Symposium on Theoretical and Computational Geodesy CY MAY 29-JUN 02, 2006 CL Wuhan, PEOPLES R CHINA SP Intercommiss Comm Theory, Int Assoc Geodesy, Wuhan Univ DE The Three-Gorges reservoir; the first water impoundment; gravity change AB This paper presents the high-precision gravity survey for the gravity changes resulting from the water load. crustal deformation and underground water level change, before and after the first (2003) water impoundment of the Three-Gorges Reservoir. We find: (i) Close to the darn, the gravity effect is the most prominent with maximum of about 200 mu gal. The gravity effect of the crustal deformation does exist. but is localized to within a few km. Gravity change resulting from underground water level change, and the impact of rainfall should not be neglected. (ii) In the area around the reservoir, the maximum gravity change is near XiangXi. Monitoring, the variation of gravity and further study of various relevant data should continue in the future. C1 [Sun, S.; Xiang, A.; Shen, C.] CEA, Inst Seismol, Wuhan 430071, Peoples R China. [Zhu, P.] Observ Royal Belgique, Uccle, Belgium. [Chao, B. F.] Natl Cent Univ, Coll Earth Sci, Taoyuan, Taiwan. [Chao, B. F.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sun, S (reprint author), CEA, Inst Seismol, Wuhan 430071, Peoples R China. RI Symposia, IAG/K-2857-2012 NR 14 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES SN 0939-9585 BN 978-3-540-74583-9 J9 IAG SYMP PY 2008 VL 132 BP 56 EP + PG 3 WC Geochemistry & Geophysics; Geosciences, Multidisciplinary SC Geochemistry & Geophysics; Geology GA BIK98 UT WOS:000260449900009 ER PT S AU Woodell, G Jobson, DJ Rabman, ZU AF Woodell, Glenn Jobson, Daniel J. Rabman, Zia-ur BE Rahman, Z Reichenbach, SE Neifeld, MA TI Scene context dependency of pattern constancy of time series imagery SO VISUAL INFORMATION PROCESSING XVII SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Visual Information Processing XVII CY MAR 18-19, 2008 CL Orlando, FL SP SPIE DE retinex; image enhancement; pattern recognition; edge detection ID VISUAL-CORTEX; MONKEY AB A fundamental element of future generic pattern recognition technology is the ability to extract similar patterns for the same scene despite wide ranging extraneous variables, including lighting, turbidity, sensor exposure variations, and signal noise. In the process of demonstrating pattern constancy of this kind for retinex/visual servo (RVS) image enhancement processing, we found that the pattern constancy performance depended somewhat on scene content. Most notably, the scene topography and, in particular, the scale and extent of the topography in an image, affects the pattern constancy the most. This paper will explore these effects in more depth and present experimental data from several time series tests. These results further quantify the impact of topography on pattern constancy. Despite this residual inconstancy, the results of overall pattern constancy testing support the idea that RVS image processing can be a universal front-end for generic visual pattern recognition. While the effects on pattern constancy were significant, the RVS processing still does achieve a high degree of pattern constancy over a wide spectrum of scene content diversity, and wide ranging extraneousness variations in lighting, turbidity, and sensor exposure. C1 [Woodell, Glenn; Jobson, Daniel J.] NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Woodell, G (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-7169-7 J9 PROC SPIE PY 2008 VL 6978 AR 69780L DI 10.1117/12.778676 PG 12 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Computer Science; Engineering; Optics; Imaging Science & Photographic Technology GA BIA03 UT WOS:000257876900016 ER PT J AU Manning, RM AF Manning, R. M. TI The relationship between the solutions of the parabolic equation method and first Rytov approximation in stochastic wave propagation theory SO WAVES IN RANDOM AND COMPLEX MEDIA LA English DT Article AB The source of the curious exact agreement between the predictions of the disparate approaches of weak and strong fluctuation theory for the mutual coherence functions of plane and spherical wave propagation is identified. It is found that the linear approximation of the Ricatti equation that results within the Rytov method reduces to the parabolic equation of strong fluctuation theory only for the plane and spherical wave cases. Such a reduction does not prevail for the general beam wave case. C1 NASA, Commun Div, Cleveland, OH USA. RP Manning, RM (reprint author), NASA, Commun Div, Cleveland, OH USA. EM Robert.M.Manning@nasa.gov NR 7 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1745-5030 J9 WAVE RANDOM COMPLEX JI Waves Random Complex Media PY 2008 VL 18 IS 4 BP 615 EP 621 DI 10.1080/17455030802232737 PG 7 WC Physics, Multidisciplinary SC Physics GA 359ON UT WOS:000259997500004 ER PT S AU Gorham, PW Allison, P Barwick, SW Beatty, JJ Besson, DZ Binns, WR Chen, C Chen, P Clem, JM Connolly, A Dowkontt, PF DuVernois, MA Field, RC Goldstein, D Goodhue, A Hast, C Hebert, CL Hoover, S Israel, MH Kowalski, J Learned, JG Liewer, KM Link, JT Lusczek, E Matsuno, S Mercurio, BC Miki, C Miocinovic, P Nam, J Naudet, CJ Ng, J Nichol, RJ Palladino, K Reil, K Romero-Wolf, A Rosen, M Ruckman, L Saltzberg, D Seckel, D Varner, GS Walz, D Wang, Y Wu, F AF Gorham, P. W. Allison, P. Barwick, S. W. Beatty, J. J. Besson, D. Z. Binns, W. R. Chen, C. Chen, P. Clem, J. M. Connolly, A. Dowkontt, P. F. DuVernois, M. A. Field, R. C. Goldstein, D. Goodhue, A. Hast, C. Hebert, C. L. Hoover, S. Israel, M. H. Kowalski, J. Learned, J. G. Liewer, K. M. Link, J. T. Lusczek, E. Matsuno, S. Mercurio, B. C. Miki, C. Miocinovic, P. Nam, J. Naudet, C. J. Ng, J. Nichol, R. J. Palladino, K. Reil, K. Romero-Wolf, A. Rosen, M. Ruckman, L. Saltzberg, D. Seckel, D. Varner, G. S. Walz, D. Wang, Y. Wu, F. BE Adams, J Halzen, F Parke, S TI Initial Results from the ANITA 2006-2007 Balloon Flight SO XXIII CONFERENCE ON NEUTRINO PHYSICS AND ASTROPHYSICS SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 23rd International Conference on Neutrino Physics and Astrophysics CY MAY 25-31, 2008 CL Christchurch, NEW ZEALAND ID COHERENT RADIO EMISSION; RAY AIR-SHOWERS; COSMIC RAYS; NEUTRINOS; CONSTRAINTS; SPECTRUM; FLUXES; CHARGE AB We report initial results of the Antarctic Impulsive Transient Antenna (ANITA) 2006-2007 Long Duration Balloon flight, which searched for evidence of the flux of cosmogenic neutrinos. ANITA flew for 35 days looking for radio impulses that might be due to the Askaryan effect in neutrino-induced electromagnetic showers within the Antarctic ice sheets. In our initial high-threshold robust analysis, no neutrino candidates are seen, with no physics background. In a non-signal horizontal-polarization channel, we do detect 6 events consistent with radio impulses from extensive air showers, which helps to validate the effectiveness of our method. Upper limits derived from our analysis now begin to eliminate the highest cosmogenic neutrino models. C1 [Gorham, P. W.; Allison, P.; Hebert, C. L.; Kowalski, J.; Learned, J. G.; Link, J. T.; Matsuno, S.; Miki, C.; Miocinovic, P.; Romero-Wolf, A.; Rosen, M.; Ruckman, L.; Varner, G. S.] Univ Hawaii, Dept Phys & Astron, Manoa, HI 96822 USA. [Gorham, P. W.; Allison, P.; Hebert, C. L.; Kowalski, J.; Learned, J. G.; Link, J. T.; Matsuno, S.; Miki, C.; Miocinovic, P.; Romero-Wolf, A.; Rosen, M.; Ruckman, L.; Varner, G. S.] Univ Hawaii Manoa, Dept Phys & Astron, Honolulu, HI 96822 USA. [Barwick, S. W.; Goldstein, D.; Nam, J.; Wu, F.] Univ Calif Irvine, Irvine, CA 92697 USA. [Beatty, J. J.; Mercurio, B. C.; Palladino, K.] Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. [Besson, D. Z.] Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. [Binns, W. R.; Dowkontt, P. F.] Washington Univ, Dept Phys, St Louis, MO 63130 USA. [Chen, C.; Chen, P.; Field, R. C.; Hast, C.; Ng, J.; Reil, K.; Walz, D.] Stand Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. [Clem, J. M.; Seckel, D.] Univ Delaware, Newark, DE 19716 USA. [Goodhue, A.; Hoover, S.; Saltzberg, D.] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [DuVernois, M. A.; Lusczek, E.] Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. [Liewer, K. M.; Naudet, C. J.] Jet Prop Lab, Pasadena, CA 91109 USA. [Connolly, A.; Nichol, R. J.] UCL, Dept Phys, London, England. [Nam, J.; Wang, Y.] Natl Taiwan Univ, Dept Phys, Taipei 10764, Taiwan. [Link, J. T.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gorham, PW (reprint author), Univ Hawaii, Dept Phys & Astron, Manoa, HI 96822 USA.; Gorham, PW (reprint author), Univ Hawaii Manoa, Dept Phys & Astron, Honolulu, HI 96822 USA. EM gorham@phys.hawaii.edu RI Nichol, Ryan/C-1645-2008; Vieregg, Abigail/D-2287-2012; Beatty, James/D-9310-2011 OI Beatty, James/0000-0003-0481-4952 FU US Department of Energy [DE-AC02-76SF00515.] FX Work supported in part by US Department of Energy contract DE-AC02-76SF00515. NR 23 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2008 VL 136 AR UNSP 022052 DI 10.1088/1742-6596/136/2/022052 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA BQO14 UT WOS:000281436000054 ER PT B AU Meyyappan, M AF Meyyappan, Meyya BE Fisher, E Selin, C Wetmore, JM TI Nanotechnology: Challenges and the Way Forward SO YEARBOOK OF NANOTECHNOLOGY IN SOCIETY, VOL I: PRESENTING FUTURES SE Yearbook of Nanotechnology in Society LA English DT Article; Book Chapter AB Nanotechnology is widely touted as the technology of the twenty first century. There is a tremendous amount of research activity across the world enabled by focused funding from governments and industry. The expectations from the society on the return on investment are high. Having followed the development of nanotechnology over the last ten years as the Director of the NASA Ames Center for Nanotechnology, I have come to identify key issues that must be resolved to realize the potential of nanotechnology. This article discusses challenges facing commercialization and evolution of the field as an enabling technology. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Meyyappan, M (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 978-1-4020-8416-4 J9 YEARB NANOTECHNOL SO PY 2008 VL 1 BP 227 EP 239 DI 10.1007/978-1-4020-8416-4_20 D2 10.1007/978-1-4020-8416-4 PG 13 WC Business; Economics; Nanoscience & Nanotechnology; Social Issues SC Business & Economics; Science & Technology - Other Topics; Social Issues GA BLM36 UT WOS:000270526100022 ER PT S AU Kreisel, J Lee, BH AF Kreisel, Joerg Lee, Burton H. BE Schrogl, KU Mathieu, C Peter, N TI Space entrepreneurship - Status & prospects SO YEARBOOK ON SPACE POLICY 2006/2007: NEW IMPETUS FOR EUROPE SE Yearbook on Space Policy LA English DT Article; Book Chapter C1 [Lee, Burton H.] Innovarium Ventures, Washington, DC USA. [Lee, Burton H.] Hewlett Packard Corp, Palo Alto, CA USA. [Lee, Burton H.] NASA, Washington, DC USA. [Lee, Burton H.] Hewlett Packard Corp, Palo Alto, CA USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, A-1201 VIENNA, AUSTRIA SN 1866-8305 BN 978-3-211-78922-3 J9 YEARB SPACE POLICY JI Yearb. Space Policy PY 2008 BP 254 EP 273 D2 10.1007/978-3-211-78923-0 PG 20 WC Engineering, Aerospace; Political Science SC Engineering; Government & Law GA BKO18 UT WOS:000268750800012 ER PT J AU Stern, JC Sonke, JE Salters, VJM AF Stern, Jennifer C. Sonke, Jeroen E. Salters, Vincent J. M. TI A capillary electrophoresis-ICP-MS study of rare earth element complexation by humic acids SO CHEMICAL GEOLOGY LA English DT Article DE lanthanides; rare earth elements; REE; humic acid; humic substances; capillary electrophoresis; conditional binding constants; ICP-MS; trace metal speciation ID PLASMA-MASS SPECTROMETRY; CONDITIONAL STABILITY-CONSTANTS; METAL-HUMATE INTERACTIONS; DISSOLVED ORGANIC-MATTER; ION-BINDING; FULVIC-ACIDS; SUBSTANCES COMPLEXATION; ACTINIDE SPECIATION; MODEL; WATER AB To predict metal-humic interactions in nature, experiments must be carried out using environmentally relevant concentrations of metal and humic substances (HS). Capillary electrophoresis coupled with ICP-MS (CE-ICP-MS) is a rapid and sensitive method to separate and detect metal species at trace-element concentrations. In this study CE-ICP-MS was used to measure partitioning of the rare earth elements (REE) between HS and a competing ligand (EDTA) under near environmental conditions (pH 6-10, 0.1 mol L_ I NaNO(3), 100 nmol L(-1) REE, 10 mg L(-1) HS). Conditional binding constants, K(c,LnHS), were calculated for REE complexed with Elliot soil humic acid, Pahokee peat humic acid, Summit Hill soil humic acid, and Suwannee River natural organic matter and compared to existing data for REE complexation by Leonardite coal humic acid and Suwannee River fulvic acid. Results of these experiments show an increase in log K(c,LnHS) with decrease in ionic radius for REE-humic complexes (the lanthanide contraction effect), overall log K,,LnHS values ranging from 9 and 16 and indicating strong REE-HS binding, and a 2.7 log unit variation in K(c,LnHs) among humic sources. The inter-humic affinity for REE correlates with proton affinity and aromaticity of the HS sources. (c) 2007 Elsevier B.V All rights reserved. C1 [Stern, Jennifer C.; Salters, Vincent J. M.] Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. [Sonke, Jeroen E.] Univ Toulouse 3, CNRS, IRD, Lab Mecan Transferts Geol, F-31400 Toulouse, France. RP Stern, JC (reprint author), NASA, Goddard Space Flight Ctr, Code 691, Greenbelt, MD 20771 USA. EM jstern@ssedmail.gsfc.nasa.gov RI Sonke, Jeroen/A-2444-2010; Stern, Jennifer/E-3135-2012; Salters, Vincent/F-9792-2014 OI Stern, Jennifer/0000-0002-0162-8807; Salters, Vincent/0000-0002-5669-7869 NR 63 TC 46 Z9 49 U1 3 U2 47 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD DEC 30 PY 2007 VL 246 IS 3-4 BP 170 EP 180 DI 10.1016/j.chemgeo.2007.09.008 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 244GK UT WOS:000251854200003 ER PT J AU Thomson, FS Marouf, EA Tyler, GL French, RG Rappoport, NJ AF Thomson, Fraser S. Marouf, Essam A. Tyler, G. Leonard French, Richard G. Rappoport, Nicole J. TI Periodic microstructure in Saturn's rings A and B SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VISCOUS OVERSTABILITY; RADIO OCCULTATION; SIMULATIONS; SCIENCE; WAKES AB Diffraction of coherent radio waves transmitted by the Cassini spacecraft at 0.94- and 3.6-cm wavelengths indicates the presence of fine-scale structure in Saturn's rings A and B, characterized by a periodic radial variation in optical depth. Interpretation of the observed spectral signature in terms of a simple diffraction grating model yields estimates of the structural period lambda(gr) approximate to 100-250 meters and orientation phi(gr) approximate to 0. In particular, two regions in Ring A of radial extent 123.05-123.4 x 10(3) km and 123.6-124.6 x 10(3) km yield average estimates of (lambda) over bar (gr) = 163 +/- 6 meters and (lambda) over bar (gr) = 217 +/- 8 meters, respectively. Three regions in Ring B of radial extent 92.1-92.6 x 10(3), 99.0-104.5 x 10(3) km, and 110.0-115.0 x 10(3) yield average estimates of (lambda) over bar (gr) = 115(-15)(+20), 146 +/- 14, and 250(-75)(+150) meters, respectively. In all regions, the structure appears to be azimuthally symmetric with -3 degrees <= phi(gr) <= 3 degrees. C1 [Thomson, Fraser S.; Tyler, G. Leonard] Stanford Univ, Ctr Radar Astron, Stanford, CA 94305 USA. [Marouf, Essam A.] San Jose State Univ, Dept Elect Engn, San Jose, CA 95192 USA. [French, Richard G.] Wellesley Coll, Dept Astron, Wellesley, MA 02181 USA. [Rappoport, Nicole J.] CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Thomson, FS (reprint author), Stanford Univ, Ctr Radar Astron, Stanford, CA 94305 USA. NR 15 TC 26 Z9 26 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 29 PY 2007 VL 34 IS 24 AR L24203 DI 10.1029/2007GL032526 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 246NH UT WOS:000252013200003 ER PT J AU Pumphrey, HC Filipiak, MJ Livesey, NJ Schwartz, MJ Boone, C Walker, KA Bernath, P Ricaud, P Barret, B Clerbaux, C Jarnot, RF Manney, GL Waters, JW AF Pumphrey, H. C. Filipiak, M. J. Livesey, N. J. Schwartz, M. J. Boone, C. Walker, K. A. Bernath, P. Ricaud, P. Barret, B. Clerbaux, C. Jarnot, R. F. Manney, G. L. Waters, J. W. TI Validation of middle-atmosphere carbon monoxide retrievals from the Microwave Limb Sounder on Aura SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID EOS MLS; CO; VARIABILITY; CALIBRATION; TRANSPORT; MISSION; MODEL AB The Microwave Limb Sounder on Aura has produced an extensive set of measurements of CO in the middle atmosphere. The measurements are usable for scientific studies from the upper troposphere up to 90 km altitude. We describe these measurements and validate them by demonstrating their internal consistency and by comparing them to other remotely sounded measurements and to 2-D model simulations. Comparisons with other measurements suggest that MLS has a positive bias of 25-50% in the mesosphere and a negative bias of up to 70% in the ( almost CO-free) lower stratosphere. The geophysical features observed in the MLS CO field show excellent qualitative agreement with other measurements. C1 [Pumphrey, H. C.; Filipiak, M. J.] Univ Edinburgh, Sch Geosci, Edinburgh EH9 3JN, Midlothian, Scotland. [Ricaud, P.; Barret, B.] Univ Toulouse 3, Observ Midi Pyrenees, CNRS, UMR 5560,Lab Aerol, F-31400 Toulouse, France. [Bernath, P.] Univ York, Dept Chem, York YO10 5DD, N Yorkshire, England. [Boone, C.] Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. [Clerbaux, C.] Univ Paris 06, Serv Aeron, Boite 102, F-75252 Paris 05, France. [Livesey, N. J.; Schwartz, M. J.; Jarnot, R. F.; Manney, G. L.; Waters, J. W.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Walker, K. A.] Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. RP Pumphrey, HC (reprint author), Univ Edinburgh, Sch Geosci, Edinburgh EH9 3JN, Midlothian, Scotland. EM h.c.pumphrey@ed.ac.uk; mjf@staffmail.ed.ac.uk; nathaniel@mls.jpl.nasa.gov; michael@mls.jpl.nasa.gov; cboone@acebox.uwaterloo.ca; kwalker@atmosp.physics.utoronto.ca; pfb500@york.ac.uk; philippe.ricaud@aero.obs-mip.fr; barp@aero.obs-mip.fr; ccl@aero.jussieu.fr; jarnot@mls.jpl.nasa.gov; manney@mls.jpl.nasa.gov; joe@mls.jpl.nasa.gov RI Bernath, Peter/B-6567-2012; Barret, Brice/I-9350-2012; Schwartz, Michael/F-5172-2016; clerbaux, cathy/I-5478-2013 OI Bernath, Peter/0000-0002-1255-396X; Barret, Brice/0000-0002-1784-4758; Schwartz, Michael/0000-0001-6169-5094; NR 25 TC 46 Z9 48 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 29 PY 2007 VL 112 IS D24 AR D24S38 DI 10.1029/2007JD008723 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NN UT WOS:000252013800003 ER PT J AU Torres, O Tanskanen, A Veihelmann, B Ahn, C Braak, R Bhartia, PK Veefkind, P Levelt, P AF Torres, Omar Tanskanen, Aapo Veihelmann, Ben Ahn, Changwoo Braak, Remco Bhartia, Pawan K. Veefkind, Pepijn Levelt, Pieternel TI Aerosols and surface UV products from Ozone Monitoring Instrument observations: An overview SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ULTRAVIOLET-RADIATION; SATELLITE ESTIMATION; OPTICAL DEPTH; ABSORBING AEROSOLS; TOMS; IRRADIANCE; OMI; NETWORK; CLIMATE; CLOUDS AB We present an overview of the theoretical and algorithmic aspects of the Ozone Monitoring Instrument (OMI) aerosol and surface UV algorithms. Aerosol properties are derived from two independent algorithms. The nearUV algorithm makes use of OMI observations in the 350-390 nm spectral region to retrieve information on the absorption capacity of tropospheric aerosols. OMI-derived information on aerosol absorption includes the UV Aerosol Index and absorption optical depth at 388 nm. The other algorithm makes use of the full UV-to-visible OMI spectral coverage to derive spectral aerosol extinction optical depth. OMI surface UV products include erythemally weighted daily dose as well as erythemal dose rate and spectral UV irradiances calculated for local solar noon conditions. The advantages and limitations of the current algorithms are discussed, and a brief summary of several validation and evaluation analysis carried out to assess the current level of uncertainty of these products is presented. C1 [Torres, Omar] Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. [Ahn, Changwoo] Sci Syst & Applicat Inc, Lanham, MD 20706 USA. [Bhartia, Pawan K.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Veihelmann, Ben; Braak, Remco; Veefkind, Pepijn; Levelt, Pieternel] Royal Netherlands Meteorol Inst, NL-3730 AE De Bilt, Netherlands. [Tanskanen, Aapo] Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. RP Torres, O (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. RI Torres, Omar/G-4929-2013; Bhartia, Pawan/A-4209-2016 OI Bhartia, Pawan/0000-0001-8307-9137 NR 53 TC 233 Z9 238 U1 1 U2 30 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 29 PY 2007 VL 112 IS D24 AR D24S47 DI 10.1029/2007JD008809 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NN UT WOS:000252013800005 ER PT J AU Vomel, H Barnes, JE Forno, RN Fujiwara, M Hasebe, F Iwasaki, S Kivi, R Komala, N Kyro, E Leblanc, T Morel, B Ogino, SY Read, WG Ryan, SC Saraspriya, S Selkirk, H Shiotani, M Canossa, JV Whiteman, DN AF Voemel, H. Barnes, J. E. Forno, R. N. Fujiwara, M. Hasebe, F. Iwasaki, S. Kivi, R. Komala, N. Kyro, E. Leblanc, T. Morel, B. Ogino, S. -Y. Read, W. G. Ryan, S. C. Saraspriya, S. Selkirk, H. Shiotani, M. Canossa, J. Valverde Whiteman, D. N. TI Validation of Aura Microwave Limb Sounder water vapor by balloon-borne Cryogenic Frost point Hygrometer measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID EOS MLS; SATELLITE; TRENDS AB Here we present extensive observations of stratospheric and upper tropospheric water vapor using the balloon-borne Cryogenic Frost point Hygrometer (CFH) in support of the Aura Microwave Limb Sounder (MLS) satellite instrument. Coincident measurements were used for the validation of MLS version 1.5 and for a limited validation of MLS version 2.2 water vapor. The sensitivity of MLS is on average 30% lower than that of CFH, which is fully compensated by a constant offset at stratospheric levels but only partially compensated at tropospheric levels, leading to an upper tropospheric dry bias. The sensitivity of MLS observations may be adjusted using the correlation parameters provided here. For version 1.5 stratospheric observations at pressures of 68 hPa and smaller MLS retrievals and CFH in situ observations agree on average to within 2.3% +/- 11.8%. At 100 hPa the agreement is to within 6.4% +/- 22% and at upper tropospheric pressures to within 23% +/- 37%. In the tropical stratosphere during the boreal winter the agreement is not as good. The "tape recorder'' amplitude in MLS observations depends on the vertical profile of water vapor mixing ratio and shows a significant interannual variation. The agreement between stratospheric observations by MLS version 2.2 and CFH is comparable to the agreement using MLS version 1.5. The variability in the difference between observations by MLS version 2.2 and CFH at tropospheric levels is significantly reduced, but a tropospheric dry bias and a reduced sensitivity remain in this version. In the validation data set a dry bias at 177.8 hPa of -24.1% +/- 16.0% is statistically significant. C1 [Voemel, H.] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. [Barnes, J. E.; Ryan, S. C.] NOAA, Earth Syst Res Lab, Hilo, HI 96720 USA. [Forno, R. N.] Univ San Andres, Atmospher Phys Lab, La Paz, Bolivia. [Fujiwara, M.; Hasebe, F.] Hokkaido Univ, Grad Sch Environm Earth Sci, Sapporo, Hokkaido 0600810, Japan. [Iwasaki, S.] Natl Def Acad, Kanagawa 2398686, Japan. [Kivi, R.; Kyro, E.] Finnish Meteorol Inst, Sodankyla, Finland. [Komala, N.; Saraspriya, S.] Lembaga Penerbangan Antariksa Nas, Bandung, Indonesia. [Leblanc, T.; Read, W. G.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Morel, B.] Reunion Univ, Lab Phys Atmosphere, St Denis, Reunion. [Ogino, S. -Y.] Japan Agcy Marine Earth Sci & Technol, Yokosuka, Kanagawa 2370061, Japan. [Selkirk, H.] Bay Area Environm Res Inst, Sonoma, CA 95476 USA. [Shiotani, M.] Kyoto Univ, Res Inst Sustainable Humanosphere, Kyoto 6110011, Japan. [Canossa, J. Valverde] Univ Nacl, Heredia, Costa Rica. [Whiteman, D. N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Vomel, H (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Campus Box 216, Boulder, CO 80309 USA. EM holger.voemel@colorado.edu RI Fujiwara, Masatomo/F-7852-2012 NR 10 TC 36 Z9 37 U1 2 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 29 PY 2007 VL 112 IS D24 AR D24S37 DI 10.1029/2007JD008698 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NN UT WOS:000252013800002 ER PT J AU Hock, AN Cabrol, NA Dohm, JM Piatek, J Warren-Rhodes, K Weinstein, S Wettergreen, DS Grin, EA Moersch, J Cockell, CS Coppin, P Ernst, L Fisher, G Hardgrove, C Marinangeli, L Minkley, E Ori, GG Waggoner, A Wyatt, M Smith, T Thompson, D Wagner, M Jonak, D Stubbs, K Thomas, G Pudenz, E Glasgow, J AF Hock, Andrew N. Cabrol, Nathalie A. Dohm, James M. Piatek, Jennifer Warren-Rhodes, Kim Weinstein, Shmuel Wettergreen, David S. Grin, Edmond A. Moersch, Jeffrey Cockell, Charles S. Coppin, Peter Ernst, Lauren Fisher, Gregory Hardgrove, Craig Marinangeli, Lucia Minkley, Edwin Ori, Gian Gabriele Waggoner, Alan Wyatt, Mike Smith, Trey Thompson, David Wagner, Michael Jonak, Dominic Stubbs, Kristen Thomas, Geb Pudenz, Erin Glasgow, Justin TI Life in the Atacama: A scoring system for habitability and the robotic exploration for life SO JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES LA English DT Article ID THARSIS REGION; MARS; CALIFORNIA; NEOGENE; VALLEYS; OCEANS; CHILE; BASIN; WATER; FIELD AB [1] The science goals of the Life in the Atacama (LITA) robotic field experiment are to understand habitat and seek out life in the Atacama Desert, Chile, as an analog to future missions to Mars. To those ends, we present a new data analysis tool, the LITA Data Scoring System (DSS), which (1) integrates rover and orbital data relevant to environmental habitability and life detection, and (2) provides a standard metric, or "score'' to evaluate (a) the potential habitability, and (b) the strength of evidence for life at all locales along the rover's traverse. Designed and tested during the 2005 field campaign, first results from the DSS indicate that the three selected sites in the Atacama Desert are generally inhospitable. The strength of evidence for life is positively correlated with potential habitability at two of the three sites. Using factor analysis, we find three factors explain 79.9% of the variance in biological observations and five factors explain 96.2% of the variance in potential habitability across all sites. These factors are used to focus a discussion of scoring variable definitions for future robotic missions in the Atacama and of instrument selection and strategy development for future robotic missions on Earth and Mars. C1 [Hock, Andrew N.] Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA. [Cabrol, Nathalie A.; Warren-Rhodes, Kim; Grin, Edmond A.] NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. [Cabrol, Nathalie A.; Warren-Rhodes, Kim; Grin, Edmond A.] SETI Inst, Mountain View, CA USA. [Dohm, James M.] Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ USA. [Piatek, Jennifer; Moersch, Jeffrey; Hardgrove, Craig; Wyatt, Mike] Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN USA. [Weinstein, Shmuel; Ernst, Lauren; Fisher, Gregory; Minkley, Edwin; Waggoner, Alan] Carnegie Mellon Univ, Mellon Inst, Mol Biosensor & Imaging Ctr, Pittsburgh, PA 15213 USA. [Wettergreen, David S.; Smith, Trey; Thompson, David; Wagner, Michael; Jonak, Dominic; Stubbs, Kristen] Carnegie Mellon Univ, Inst Robot, Pittsburgh, PA 15213 USA. [Cockell, Charles S.] Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. [Coppin, Peter] Carnegie Mellon Univ, Remote Exp & Learning Lab, Pittsburgh, PA 15213 USA. [Marinangeli, Lucia; Ori, Gian Gabriele] Int Res Sch Planetary Sci, Pescara, Italy. [Thomas, Geb; Pudenz, Erin; Glasgow, Justin] Univ Iowa, GROK Lab, Iowa City, IA USA. RP Hock, AN (reprint author), Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA. RI Moersch, Jeffrey/F-7189-2010; Hardgrove, Craig/C-7333-2011; Dohm, James/A-3831-2014; OI ORI, Gian Gabriele/0000-0002-6460-1476 NR 36 TC 5 Z9 5 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-BIOGEO JI J. Geophys. Res.-Biogeosci. PD DEC 29 PY 2007 VL 112 IS G4 AR G04S08 DI 10.1029/2006JG000321 PG 14 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 246NR UT WOS:000252014200001 ER PT J AU Lichtenberg, KA Arvidson, RE Poulet, F Morris, RV Knudson, A Bell, JF Bellucci, G Bibring, JP Farrand, WH Johnson, JR Ming, DW Pinet, PC Rogers, AD Squyres, SW AF Lichtenberg, Kimberly A. Arvidson, Raymond E. Poulet, Francois Morris, Richard V. Knudson, Amy Bell, James F. Bellucci, Giancarlo Bibring, Jean-Pierre Farrand, William H. Johnson, Jeffrey R. Ming, Douglas W. Pinet, Patrick C. Rogers, A. Deanne Squyres, Steven W. TI Coordinated analyses of orbital and Spirit Rover data to characterize surface materials on the cratered plains of Gusev Crater, Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID OMEGA/MARS EXPRESS; THERMAL INERTIA; BASALTIC ROCKS; LANDING-SITE; SOILS; MISSION; LOCALIZATION; SPECTROMETER; OPPORTUNITY; DIVERSITY AB Comparison of the Mars Exploration Rover Spirit's Pancam (0.4 to 1.0 mu m) and Mars Express Observatoire pour la Mineralogie l'Eau, les Glaces et l'Activite (OMEGA) (0.4 to 2.5 mu m) spectral reflectance data over Spirit's traverses shows that Gusev cratered plains are dominated by nanophase ferric-oxide-rich dust covering weakly altered basaltic sands. This interpretation is also consistent with both observations from OMEGA data covering plains beyond the traverse region and interpretations of data from the other payload instruments on the Spirit Rover. OMEGA observations of relatively low albedo regions where dust has presumably been stripped by dust devils show negative spectral reflectance slopes from 1.5 to 2.5 mu m and moderately masked spectral features which are indicative of olivine or pyroxene. High-albedo regions north and south of the Spirit landing site have flat spectral reflectance slopes and few spectral features, although all spectra have a nanophase ferric-oxide absorption edge between 0.4 and 0.75 mu m. Comparison of THEMIS-derived thermal inertia values with OMEGA-derived spectral parameters shows that although the dust cover can be optically thick (0.4 to 2.5 mu m wavelength region) in some areas, it is not thick enough (similar to 1 cm) to mask the thermal inertia of the underlying substrate for areas included in this study. C1 [Lichtenberg, Kimberly A.; Arvidson, Raymond E.; Knudson, Amy] Washington Univ, Dept Earth & Planetary Sci, McDonnell Ctr Space Sci, St Louis, MO 63130 USA. [Bell, James F.; Squyres, Steven W.] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. [Bellucci, Giancarlo] Inst Fis Spazio Interplanetario, INAF, I-00133 Rome, Italy. [Poulet, Francois; Bibring, Jean-Pierre] Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. [Farrand, William H.] Space Sci Inst, Boulder, CO 80301 USA. [Johnson, Jeffrey R.] US Geol Survey, Astrogeol Team, Flagstaff, AZ 86001 USA. [Morris, Richard V.; Ming, Douglas W.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. [Rogers, A. Deanne] CALTECH, Pasadena, CA 91125 USA. [Pinet, Patrick C.] Observ Midi Pyrenees, F-31400 Toulouse, France. RP Lichtenberg, KA (reprint author), Washington Univ, Dept Earth & Planetary Sci, McDonnell Ctr Space Sci, 1 Brookings Dr, St Louis, MO 63130 USA. EM lichtenberg@wunder.wustl.edu RI Johnson, Jeffrey/F-3972-2015; Rogers, Deanne/I-9737-2016; OI Rogers, Deanne/0000-0002-4671-2551; Bellucci, Giancarlo/0000-0003-0867-8679 NR 51 TC 21 Z9 21 U1 1 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 29 PY 2007 VL 112 IS E12 AR E12S90 DI 10.1029/2006JE002850 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 246OC UT WOS:000252015400001 ER PT J AU Haider, SA Singh, V Choksi, VR Maguire, WC Verigin, MI AF Haider, S. A. Singh, V. Choksi, V. R. Maguire, W. C. Verigin, M. I. TI Calculated densities of H(3)O(+)(H(2)O)n, NO(2)(-) (H(2)O)n, CO(3)(-) (H2O)(n) and electron in the nighttime ionosphere of Mars: Impact of solar wind electron and galactic cosmic rays SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID RADIO OCCULTATION MEASUREMENTS; MARTIAN ATMOSPHERE; MODEL; MARINER-9; IONS AB [1] We have calculated the densities of positive ions and negative ions in the ionosphere of Mars at solar zenith angle 106 degrees between height interval 0 km and 220 km. This model couples ion-neutral, electron neutral, dissociation of positive and negative ions, electron detachment, ion-ion, ion-electron recombination processes through 117 chemical reactions. Of the 34 ions considered in the model, the chemistry of 17 major ions (O(2)(+), NO(+), CO(2)(+), H(3)O(+)H(2)O, H(3)O(+)(H(2)O)(2), H(3)O(+)(H(2)O)(3), H(3)O(+)(H(2)O)(4), O(2)(+)CO(2), H(3)O(+), CO(4)(-), CO(3)(-), CO(3)(-) H(2)O, CO(3)(-) (H(2)O)(2), NO(2)(-)H(2)O, NO(2)(-)(H(2)O)(2), NO(3)(-)H(2)O, and NO(3)(-) (H(2)O)(2)) are discussed in this paper. At altitude below 70 km, the electron density is mainly controlled by hydrated hydronium ions and water clusters of NO(2)(-) and CO(3)(-). The ions O(2)(+) and NO(+) dominate above this altitude. This calculation suggests that the ionosphere of Mars contains F and D peaks at altitude similar to 130 km and similar to 30 km due to precipitation of solar wind electron and galactic cosmic rays respectively. F peak is mainly produced by O(2)(+) after heavy loss of CO(2)(+) with atomic oxygen. D peak occurs due to high efficiency of electron attachment to Ox molecules, which entails that concentration of negative ions is higher than that of electron below 30 km. These results are compared with radio measurements made by Mars 4 and Mars 5 in the nighttime ionosphere. C1 [Haider, S. A.; Choksi, V. R.] Phys Res Lab, Ahmadabad 380009, Gujarat, India. [Singh, V.] Univ Brescia, I-25121 Brescia, Italy. [Maguire, W. C.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Verigin, M. I.] Moscow Space Res Inst, Moscow 117810, Russia. RP Haider, SA (reprint author), Phys Res Lab, Ahmadabad 380009, Gujarat, India. EM haider@prl.res.in NR 35 TC 20 Z9 20 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 29 PY 2007 VL 112 IS A12 AR A12309 DI 10.1029/2007JA012530 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 246OJ UT WOS:000252016100005 ER PT J AU Popp, PJ Marcy, TP Watts, LA Gao, RS Fahey, DW Weinstock, EM Smith, JB Herman, RL Troy, RF Webster, CR Christensen, LE Baumgardner, DG Voigt, C Karcher, B Wilson, JC Mahoney, MJ Jensen, EJ Bui, TP AF Popp, P. J. Marcy, T. P. Watts, L. A. Gao, R. S. Fahey, D. W. Weinstock, E. M. Smith, J. B. Herman, R. L. Troy, R. F. Webster, C. R. Christensen, L. E. Baumgardner, D. G. Voigt, C. Kaercher, B. Wilson, J. C. Mahoney, M. J. Jensen, E. J. Bui, T. P. TI Condensed-phase nitric acid in a tropical subvisible cirrus cloud SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NASA ER-2; TROPOPAUSE; SPECTROMETER; DEHYDRATION; AIRCRAFT; HNO3; ICE; DENITRIFICATION; STRATOSPHERE; INSTRUMENT AB [1] In situ observations in a tropical subvisible cirrus cloud during the Costa Rica Aura Validation Experiment on 2 February 2006 show the presence of condensed-phase nitric acid. The cloud was observed near the tropopause at altitudes of 16.3-17.7 km in an extremely cold ( 183-191 K) and dry (< 5 ppm H2O) air mass. Relative humidities with respect to ice ranged from 150-250% throughout most of the cloud. Optical particle measurements indicate the presence of ice crystals as large as 90 mu m in diameter. Condensed HNO3/H2O molar ratios observed in the cloud particles were 1-2 orders of magnitude greater than ratios observed previously in cirrus clouds at similar HNO3 partial pressures. Nitric acid trihydrate saturation ratios were 10 or greater during much of the cloud encounter, indicating that HNO3 may be present in the cloud particles as a stable condensate and not simply physically adsorbed on or trapped in the particles. C1 [Popp, P. J.; Marcy, T. P.; Gao, R. S.; Fahey, D. W.] NOAA Earth Syst Res Lab, Div Chem Sci, Boulder, CO 80305 USA. [Popp, P. J.; Marcy, T. P.; Watts, L. A.] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. [Weinstock, E. M.; Smith, J. B.] Harvard Univ, Atmospher Res Project, Cambridge, MA 02138 USA. [Herman, R. L.; Troy, R. F.; Webster, C. R.; Christensen, L. E.; Mahoney, M. J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Baumgardner, D. G.] Univ Nacl Autonoma Mexico, Ctr Ciencias Atmosfera, Mexico City 04150, DF, Mexico. [Voigt, C.; Kaercher, B.] Deutsches Zentrum Luft & Raumfahrt, Inst Phys Atmosphare, D-82230 Oberpfaffenhofen, Wessling, Germany. [Wilson, J. C.] Univ Denver, Dept Engn, Denver, CO 80208 USA. [Jensen, E. J.; Bui, T. P.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Popp, PJ (reprint author), NOAA Earth Syst Res Lab, Div Chem Sci, 325 Broadway R-AL6, Boulder, CO 80305 USA. EM peter.j.popp@noaa.gov RI Voigt, Christiane/G-3279-2010; Herman, Robert/H-9389-2012; Gao, Ru-Shan/H-7455-2013; Karcher, Bernd/D-5325-2014; Watts, Laurel/G-4532-2013; Fahey, David/G-4499-2013; Manager, CSD Publications/B-2789-2015 OI Herman, Robert/0000-0001-7063-6424; Karcher, Bernd/0000-0003-0278-4980; Watts, Laurel/0000-0002-0834-3329; Fahey, David/0000-0003-1720-0634; NR 24 TC 12 Z9 12 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 28 PY 2007 VL 34 IS 24 AR L24812 DI 10.1029/2007GL031832 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 246NF UT WOS:000252013000005 ER PT J AU Jacobson, MZ Kaufman, YJ Rudich, Y AF Jacobson, Mark Z. Kaufman, Yoram J. Rudich, Yinon TI Examining feedbacks of aerosols to urban climate with a model that treats 3-D clouds with aerosol inclusions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LOS-ANGELES BASIN; AIR-POLLUTION; BOUNDARY-LAYER; NUMERICAL SIMULATIONS; GLOBAL CLIMATE; PART I; SENSITIVITY EXPERIMENTS; EXPLICIT MICROPHYSICS; CONDENSATION NUCLEI; SIZE DISTRIBUTIONS AB [1] Anthropogenic aerosol particles alter clouds, radiation, and precipitation, thereby affecting weather, climate, and air pollution. To examine and understand such feedbacks, a module that simulates the evolution, movement, and microphysics of three-dimensional size-resolved mixed-phase clouds and precipitation and their multicomponent aerosol inclusions was developed and implemented into the GATOR-GCMOM global-through-urban air pollution-weather-climate model. A unique feature of the module is that aerosol particles and their chemical components are tracked in time and space within size-resolved liquid, ice, and graupel and interstitially within clouds. Modeled parameters were evaluated against in situ data, compared with MODIS climatologies, and nested with emission data down to 5 km resolution to study aerosol-cloud feedbacks in Los Angeles. Although updrafts are not resolved during deep convection at this resolution, most convection is shallow in Los Angeles. This resolution is also near the lower limit for which a hydrostatic solution to vertical momentum (used here) is similar to a nonhydrostatic solution. Aerosols in Los Angeles were found to increase cloud optical depth, cloud liquid water, cloud fraction, net downward thermal-infrared radiation, soil moisture, the relative humidity, and (slightly) middle-boundary layer air temperatures. Aerosols also decreased precipitation, surface solar, and near-surface temperatures. Both boundary layer warming due to black carbon and surface cooling due to all aerosol components increased stability, inhibiting cloud top growth under some conditions. Aerosols may feed back to themselves by increasing cloud liquid, gas dissolution, and aerosol volume upon evaporation. They may also decrease visibility by increasing the relative humidity and decrease photolysis below them by enhancing cloud thickness. C1 [Jacobson, Mark Z.] Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. [Kaufman, Yoram J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Rudich, Yinon] Weizmann Inst Sci, Dept Environm Sci, IL-76100 Rehovot, Israel. RP Jacobson, MZ (reprint author), Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. RI Rudich, Yinon/K-1498-2012; OI Rudich, Yinon/0000-0003-3149-0201 NR 91 TC 48 Z9 49 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 28 PY 2007 VL 112 IS D24 AR D24205 DI 10.1029/2007JD008922 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NM UT WOS:000252013700013 ER PT J AU Read, WG Lambert, A Bacmeister, J Cofield, RE Christensen, LE Cuddy, DT Daffer, WH Drouin, BJ Fetzer, E Froidevaux, L Fuller, R Herman, R Jarnot, RF Jiang, JH Jiang, YB Kelly, K Knosp, BW Kovalenko, LJ Livesey, NJ Liu, HC Manney, GL Pickett, HM Pumphrey, HC Rosenlof, KH Sabounchi, X Santee, ML Schwartz, MJ Snyder, WV Stek, PC Su, H Takacs, LL Thurstans, RP Vomel, H Wagner, PA Waters, JW Webster, CR Weinstock, EM Wu, DL AF Read, W. G. Lambert, A. Bacmeister, J. Cofield, R. E. Christensen, L. E. Cuddy, D. T. Daffer, W. H. Drouin, B. J. Fetzer, E. Froidevaux, L. Fuller, R. Herman, R. Jarnot, R. F. Jiang, J. H. Jiang, Y. B. Kelly, K. Knosp, B. W. Kovalenko, L. J. Livesey, N. J. Liu, H. -C. Manney, G. L. Pickett, H. M. Pumphrey, H. C. Rosenlof, K. H. Sabounchi, X. Santee, M. L. Schwartz, M. J. Snyder, W. V. Stek, P. C. Su, H. Takacs, L. L. Thurstans, R. P. Vomel, H. Wagner, P. A. Waters, J. W. Webster, C. R. Weinstock, E. M. Wu, D. L. TI Aura Microwave Limb Sounder upper tropospheric and lower stratospheric H2O and relative humidity with respect to ice validation SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PRESSURE-INDUCED LINESHAPE; WATER-VAPOR; ROTATIONAL TRANSITIONS; ATMOSPHERIC RADIATION; EOS MLS; TEMPERATURE; ABSORPTION; MILLIMETER; AIRCRAFT; OXYGEN AB [1] The validation of version 2.2 (v2.2) H2O measurements from the Earth Observing System (EOS) Microwave Limb Sounder (Aura MLS) on the Aura satellite are presented. Results from comparisons made with Aqua Atmospheric Infrared Sounder (AIRS), Vaisala radiosondes, frost point hygrometer, and WB57 aircraft hygrometers are presented. Comparisons with the Aura MLS v1.5 H2O, Goddard global modeling and assimilation office Earth Observing System analyses (GEOS-5) are also discussed. For H2O mixing ratios less than 500 ppmv, the MLS v2.2 has an accuracy better than 25% between 316 and 147 hPa. The precision is 65% at 316 hPa that reduces to 25% at 147 hPa. This performance is better than expected from MLS measurement systematic error analyses. MLS overestimates H2O for mixing ratios greater than 500 ppmv which is consistent with a scaling error in either the calibrated or calculated MLS radiances. The validation of the accuracy of MLS v2.2 H2O from 121 to 83 hPa which is expected to be better than 15% cannot be confirmed at this time because of large disagreements among the hygrometers used in the AVE campaigns. The precision of the v2.2 H2O from 121 to 83 hPa is 10 - 20%. The vertical resolution is 1.5 - 3.5 km depending on height. The horizontal resolution is 210 x 7 km(2) along and perpendicular to the Aura orbit track, respectively. Relative humidity is calculated from H2O and temperature. The precision, accuracy, and spatial resolution are worse than for H2O. C1 [Read, W. G.; Lambert, A.; Cofield, R. E.; Christensen, L. E.; Cuddy, D. T.; Daffer, W. H.; Drouin, B. J.; Fetzer, E.; Froidevaux, L.; Fuller, R.; Herman, R.; Jarnot, R. F.; Jiang, J. H.; Jiang, Y. B.; Knosp, B. W.; Kovalenko, L. J.; Livesey, N. J.; Manney, G. L.; Pickett, H. M.; Sabounchi, X.; Santee, M. L.; Schwartz, M. J.; Snyder, W. V.; Stek, P. C.; Su, H.; Thurstans, R. P.; Wagner, P. A.; Waters, J. W.; Webster, C. R.; Wu, D. L.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. [Bacmeister, J.; Takacs, L. L.] NASA, Goddard Space Flight Ctr, Globa Modeling & Assimilat Off, Greenbelt, MD 20771 USA. [Kelly, K.; Rosenlof, K. H.] NOAA, Earth Syst Res Lab, Div Chem Sci, Boulder, CO USA. [Pumphrey, H. C.] Univ Edinburgh, Dept Meteorol, Edinburgh, Midlothian, Scotland. [Vomel, H.] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. [Weinstock, E. M.] Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA. RP Read, WG (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RI Rosenlof, Karen/B-5652-2008; Herman, Robert/H-9389-2012; Schwartz, Michael/F-5172-2016; Wu, Dong/D-5375-2012; Manager, CSD Publications/B-2789-2015 OI Rosenlof, Karen/0000-0002-0903-8270; Herman, Robert/0000-0001-7063-6424; Schwartz, Michael/0000-0001-6169-5094; NR 67 TC 146 Z9 147 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 28 PY 2007 VL 112 IS D24 AR D24S35 DI 10.1029/2007JD008752 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NM UT WOS:000252013700010 ER PT J AU Santee, ML Lambert, A Read, WG Livesey, NJ Cofield, RE Cuddy, DT Daffer, WH Drouin, BJ Froidevaux, L Fuller, RA Jarnot, RF Knosp, BW Manney, GL Perun, VS Snyder, WV Stek, PC Thurstans, RP Wagner, PA Waters, JW Muscari, G de Zafra, RL Dibb, JE Fahey, DW Popp, PJ Marcy, TP Jucks, KW Toon, GC Stachnik, RA Bernath, PF Boone, CD Walker, KA Urban, J Murtagh, D AF Santee, M. L. Lambert, A. Read, W. G. Livesey, N. J. Cofield, R. E. Cuddy, D. T. Daffer, W. H. Drouin, B. J. Froidevaux, L. Fuller, R. A. Jarnot, R. F. Knosp, B. W. Manney, G. L. Perun, V. S. Snyder, W. V. Stek, P. C. Thurstans, R. P. Wagner, P. A. Waters, J. W. Muscari, G. de Zafra, R. L. Dibb, J. E. Fahey, D. W. Popp, P. J. Marcy, T. P. Jucks, K. W. Toon, G. C. Stachnik, R. A. Bernath, P. F. Boone, C. D. Walker, K. A. Urban, J. Murtagh, D. TI Validation of the Aura Microwave Limb Sounder HNO3 measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NITRIC-ACID; LOWER STRATOSPHERE; MILLIMETER-WAVE; EOS MLS; SATELLITE; SUBMILLIMETER; RETRIEVALS; CHEMISTRY; PROFILES; MISSION AB [1] We assess the quality of the version 2.2 (v2.2) HNO3 measurements from the Microwave Limb Sounder (MLS) on the Earth Observing System Aura satellite. The MLS HNO3 product has been greatly improved over that in the previous version (v1.5), with smoother profiles, much more realistic behavior at the lowest retrieval levels, and correction of a high bias caused by an error in one of the spectroscopy files used in v1.5 processing. The v2.2 HNO3 data are scientifically useful over the range 215 to 3.2 hPa, with single-profile precision of similar to 0.7 ppbv throughout. Vertical resolution is 3-4 km in the upper troposphere and lower stratosphere, degrading to similar to 5 km in the middle and upper stratosphere. The impact of various sources of systematic uncertainty has been quantified through a comprehensive set of retrieval simulations. In aggregate, systematic uncertainties are estimated to induce in the v2.2 HNO3 measurements biases that vary with altitude between +/- 0.5 and +/- 2 ppbv and multiplicative errors of +/- 5-15% throughout the stratosphere, rising to similar to +/- 30% at 215 hPa. Consistent with this uncertainty analysis, comparisons with correlative data sets show that relative to HNO3 measurements from ground- based, balloon- borne, and satellite instruments operating in both the infrared and microwave regions of the spectrum, MLS v2.2 HNO3 mixing ratios are uniformly low by 10-30% throughout most of the stratosphere. Comparisons with in situ measurements made from the DC-8 and WB-57 aircraft in the upper troposphere and lowermost stratosphere indicate that the MLS HNO3 values are low in this region as well, but are useful for scientific studies (with appropriate averaging). C1 [Santee, M. L.; Lambert, A.; Read, W. G.; Livesey, N. J.; Cofield, R. E.; Cuddy, D. T.; Daffer, W. H.; Drouin, B. J.; Froidevaux, L.; Fuller, R. A.; Jarnot, R. F.; Knosp, B. W.; Manney, G. L.; Perun, V. S.; Snyder, W. V.; Stek, P. C.; Thurstans, R. P.; Wagner, P. A.; Waters, J. W.; Toon, G. C.; Stachnik, R. A.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. [Manney, G. L.] New Mexico Inst Min & Technol, Dept Phys, Socorro, NM 87801 USA. [Muscari, G.] Ist Nazl Geofis & Vulcanol, Rome, Italy. [de Zafra, R. L.] SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. [Dibb, J. E.] SUNY Stony Brook, Inst Terr & Planetary Atmospheres, Stony Brook, NY 11794 USA. [Dibb, J. E.] Univ New Hampshire, Inst Study Earth Oceans & Space, Climate Change Res Ctr, Durham, NH 03824 USA. [Fahey, D. W.; Popp, P. J.; Marcy, T. P.] Earth Syst Res Lab, Div Chem Sci, Boulder, CO USA. [Marcy, T. P.] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. [Jucks, K. W.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Bernath, P. F.; Boone, C. D.; Walker, K. A.] Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. [Bernath, P. F.] Univ York, Dept Chem, York YO10 5DD, N Yorkshire, England. [Walker, K. A.] Univ Toronto, Dept Phys, Toronto, ON, Canada. [Urban, J.; Murtagh, D.] Chalmers, Dept Radio & Space Sci, S-41296 Gothenburg, Sweden. RP Santee, ML (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RI Bernath, Peter/B-6567-2012; Urban, Jo/F-9172-2010; Fahey, David/G-4499-2013; Murtagh, Donal/F-8694-2011; Manager, CSD Publications/B-2789-2015 OI Bernath, Peter/0000-0002-1255-396X; Urban, Jo/0000-0001-7026-793X; Fahey, David/0000-0003-1720-0634; Murtagh, Donal/0000-0003-1539-3559; NR 51 TC 56 Z9 57 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 28 PY 2007 VL 112 IS D24 AR D24S40 DI 10.1029/2007JD008721 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NM UT WOS:000252013700008 ER PT J AU Schmidt, KS Pilewskie, P Platnick, S Wind, G Yang, P Wendisch, M AF Schmidt, K. Sebastian Pilewskie, Peter Platnick, Steven Wind, Gala Yang, Ping Wendisch, Manfred TI Comparing irradiance fields derived from Moderate Resolution Imaging Spectroradiometer airborne simulator cirrus cloud retrievals with solar spectral flux radiometer measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RADIATION BUDGET EXPERIMENT; ICE CRYSTALS; OPTICAL-THICKNESS; EXPERIMENT ERBE; LIQUID WATER; REFLECTANCE; SCATTERING; CLIMATE; MODELS; SYSTEM AB [1] During the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment, the Moderate Resolution Imaging Spectroradiometer (MODIS) airborne simulator (MAS) and the solar spectral flux radiometer (SSFR) operated on the same aircraft, the NASA ER-2. While MAS provided two-dimensional horizontal fields of cloud optical thickness and effective ice particle radius, the SSFR measured spectral irradiance in the visible to near-infrared wavelength range (0.3-1.7 mu m). The MAS retrievals, along with vertical profiles from a combined radar/lidar system on board the same aircraft were used to construct three- dimensional cloud fields, which were input into Monte Carlo radiative transfer models. The simulated field of spectral albedo (ratio of reflected upwelling to incident downwelling irradiance) was compared with the SSFR measurements. For two cases, the relative importance of spatial cloud heterogeneities, various approximations of the single scattering parameters, vertical structure, cirrus optical thickness, and ice crystal effective radius was studied. C1 [Schmidt, K. Sebastian; Pilewskie, Peter] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. [Platnick, Steven; Wind, Gala] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Wind, Gala] SSAI Inc, Lanham, MD USA. [Yang, Ping] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX USA. [Wendisch, Manfred] Johannes Gutenberg Univ Mainz, Inst Atmospher Phys, Mainz, Germany. RP Schmidt, KS (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Campus Box 392, Boulder, CO 80309 USA. RI Yang, Ping/B-4590-2011; SCHMIDT, KONRAD SEBASTIAN/C-1258-2013; Platnick, Steven/J-9982-2014; Wendisch, Manfred/E-4175-2013 OI SCHMIDT, KONRAD SEBASTIAN/0000-0003-3899-228X; Platnick, Steven/0000-0003-3964-3567; Wendisch, Manfred/0000-0002-4652-5561 NR 33 TC 5 Z9 5 U1 2 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 28 PY 2007 VL 112 IS D24 AR D24206 DI 10.1029/2007JD008711 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NM UT WOS:000252013700007 ER PT J AU Smith, GL AF Smith, G. Louis TI Earth-emitted irradiance near the first Lagrangian point SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID VIEW RADIOMETER MEASUREMENTS; RADIATION BUDGET EXPERIMENT; DECONVOLUTION AB [1] The first Lagrangian point, L-1, is a point between the Earth and the Sun where a mass will be in equilibrium between the gravitational pulls of Earth and Sun and its centrifugal force about the center of mass of the Earth-Sun system. DSCOVER, the first spacecraft planned for Earth observation near L-1, includes a radiometer to measure shortwave and longwave flux from the full disc of the Earth. The latitude of the subsatellite point is near the solar declination, and its longitude is near that for local noon. The spacecraft is always over the tropics. Moreover, it is always over the summer hemisphere. Both of these effects will cause the full- disc measurement of Earth-emitted radiation to be higher than the global mean. In this paper we compute the longwave flux near L-1 using deconvolution theory for wide field-of-view radiometer measurements of Earth-emitted radiation, which makes the computations simple and provides a theoretical framework for understanding the results. The bias due to being over the summer hemisphere will peak twice during the year, so that a semiannual cycle will occur. The global mean Earth-emitted radiation has an annual cycle due to the variation of Earth-Sun distance. If the spacecraft orbit is less than 10 degrees from the Earth-Sun line, the bias to the global mean is computed to be about 8 W m(-2) for the annual average with a semiannual cycle of about 1.5 W m(-2). In addition to the seasonal cycles, there is a diurnal cycle in the measurement at L-1 as the Earth rotates. C1 NASA, Langley Res Ctr, Natl Inst Aerosp, Hampton, VA 23665 USA. RP Smith, GL (reprint author), NASA, Langley Res Ctr, Natl Inst Aerosp, Hampton, VA 23665 USA. NR 16 TC 0 Z9 0 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 28 PY 2007 VL 112 IS D24 AR D24115 DI 10.1029/2006JD007902 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NM UT WOS:000252013700001 ER PT J AU Samsonov, AA Sibeck, DG Imber, J AF Samsonov, A. A. Sibeck, D. G. Imber, J. TI MHD simulation for the interaction of an interplanetary shock with the Earth's magnetosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR-WIND SHOCK; BOW SHOCK; SUDDEN COMMENCEMENT; MASS EJECTION; MAGNETOPAUSE; WAVES; MODEL; DISCONTINUITIES; ASYMMETRY; SYSTEM AB [1] The global BATS-R-US MHD code is used to simulate the interaction of a moderately strong interplanetary shock with the Earth's magnetosphere. The model predicts the propagation of a transmitted fast shock through the magnetosheath and magnetosphere and the reflection of this shock from the inner numerical boundary. The reflected fast shock propagates sunward through the dayside magnetosphere and magnetosheath. The passage of the transmitted shock causes the bow shock and magnetopause to move inward, while the passage of the reflected fast shock causes these boundaries to move outward, consistent with previously reported in situ observations. A supplementary study employing a one-dimensional MHD model addresses the interaction of the forward fast shock with the plasmapause. This study demonstrates that most of the energy associated with the fast shock energy penetrates into the plasmasphere. Consequently, the transmitted fast wave must reach the ionosphere, produce the well known sudden impulse signatures, and then be reflected due to the shielding effects of ionospheric currents. The predictions of the numerical simulations are consistent with observations of the dayside geosynchronous magnetic field. C1 [Samsonov, A. A.] St Petersburg State Univ, Inst Phys, Dept Earth Phys, St Petersburg 198504, Russia. [Sibeck, D. G.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Imber, J.] Univ Oxford, Oxford OX1 3RH, England. RP Samsonov, AA (reprint author), St Petersburg State Univ, Inst Phys, Dept Earth Phys, St Petersburg 198504, Russia. EM samsonov@geo.phys.spbu.ru RI Sibeck, David/D-4424-2012; Samsonov, Andrey/I-7057-2012 OI Samsonov, Andrey/0000-0001-8243-1151 NR 34 TC 47 Z9 49 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 28 PY 2007 VL 112 IS A12 AR A12220 DI 10.1029/2007JA012627,2007 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 246OI UT WOS:000252016000001 ER PT J AU Yu, H Fu, R Dickinson, RE Zhang, Y Chen, M Wang, H AF Yu, Hongbin Fu, Rong Dickinson, Robert E. Zhang, Yan Chen, Mingxuan Wang, Hul. TI Interannual variability of smoke and warm cloud relationships in the Amazon as inferred from MODIS retrievals SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE aerosols; cloud; satellite remote sensing ID AEROSOL OPTICAL DEPTH; CROSS-EQUATORIAL FLOW; BOUNDARY-LAYER; LAND-SURFACE; MARINE STRATOCUMULUS; WET SEASON; ART.; MICROPHYSICS; IMPACT; SIMULATIONS AB Aerosol and cloud data from the MODerate resolution Imaging Spectroradiometer (MODIS) onboard the Earth Observing System (EOS) Aqua are used to investigate interannual variability of smoke and warm cloud relationships during the dry-to-wet transition season (August-October) over the Amazon for two years and its association with meteorological conditions. In one year (2003), smoke aerosols are associated with an increase of cloud fraction and a decrease of cloud effective radius. These effects amplify the cooling at the surface and at the top of the atmosphere (TOA) caused by the aerosol extinction. However, in another year (2002) the cloud fraction decreases with increasing aerosol optical depth. Such a decrease of cloud fraction could offset the effect of increased reflection of solar radiation by the aerosols both at the surface and at TOA. The changes in radiative fluxes between these years would contribute to interannual changes of surface energy fluxes and radiative balance at the top of the atmosphere and influence variability of the wet season onset in the basin. In 2003, the atmosphere was more humid and less stable. These conditions may be relatively favorable for the activation of aerosol particles into cloud condensation nuclei and hence cloud droplets. In 2002, the clouds were less extensive and thinner in a relatively dry atmosphere and presumably dissipated more easily. This study suggests that the aerosol-cloud relation can be influenced by atmospheric structure and convective motions, in addition to changes in aerosols properties. An adequate characterization of aerosol-cloud relationship would require a longer time series of data that includes a variety of climate conditions. The caveat of this analysis is that differences in aerosol absorption and its vertical distribution may have contributed to the observed interannual change of smoke-cloud relationship but could not be determined due to lack of adequate measurements. (c) 2007 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. RP Yu, H (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 613-2, Greenbelt, MD 20771 USA. EM hyu@climate.gsfc.nasa.gov RI Wang, Hui/B-6516-2008; Yu, Hongbin/C-6485-2008; Zhang, Yan/C-4792-2012; Fu, Rong/B-4922-2011 OI Yu, Hongbin/0000-0003-4706-1575; NR 62 TC 16 Z9 16 U1 0 U2 6 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 EI 1879-0704 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD DEC 28 PY 2007 VL 111 IS 4 BP 435 EP 449 DI 10.1016/j.rse.2007.04.003 PG 15 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 233OD UT WOS:000251099300003 ER PT J AU Fovell, RG Su, H AF Fovell, Robert G. Su, Hui TI Impact of cloud microphysics on hurricane track forecasts SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TROPICAL CYCLONE MOTION; PART II; SENSITIVITY; SIMULATION; VORTEX; MODEL; EVOLUTION AB Simulations of Hurricane Rita (2005) at operational resolutions (30 and 12 km) reveal significant track sensitivity to cloud microphysical details, rivaling variation seen in the National Hurricane Center's multimodel consensus forecast. Microphysics appears to directly or indirectly modulate vortex characteristics including size and winds at large radius and possibly other factors involved in hurricane motion. Idealized simulations made at higher (3 km) resolution help isolate the microphysical influence. C1 [Fovell, Robert G.] Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA. [Su, Hui] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Fovell, RG (reprint author), Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA. EM rfovell@ucla.edu; hui.su@jpl.nasa.edu NR 15 TC 25 Z9 27 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 27 PY 2007 VL 34 IS 24 AR L24810 DI 10.1029/2007GL031723 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 246NE UT WOS:000252012900005 ER PT J AU Lin, JL Kim, D Lee, MI Kang, IS AF Lin, Jia-Lin Kim, Daehyun Lee, Myong-In Kang, In-Sik TI Effects of cloud-radiative heating on atmospheric general circulation model (AGCM) simulations of convectively coupled equatorial waves SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MADDEN-JULIAN OSCILLATION; TROPICAL INTRASEASONAL OSCILLATIONS; LOW-FREQUENCY; PART I; CLIMATE MODEL; KELVIN WAVES; FGGE DATA; EL-NINO; VARIABILITY; PACIFIC AB This study examines the effects of cloud-radiative heating on convectively coupled equatorial waves simulated by the Seoul National University (SNU) atmospheric general circulation model (AGCM). The strength of cloud-radiative heating is adjusted by modifying the autoconversion rate needed for cloud condensates to grow up to raindrops. The results show that increasing the autoconversion rate has little effect on the climatological mean precipitation, but it significantly reduces the time-mean clouds and radiative heating in the upper troposphere and enhances heating due to moist processes in the middle troposphere. These lead to cooling of time-mean upper troposphere temperature and drying of lower-troposphere moisture. Reduction of cloud-radiative heating enhances the prominence of Kelvin and n = 0 eastward inertial gravity (EIG) waves. It also tends to enhance significantly the variance of the Kelvin, equatorial Rossby (ER), mixed Rossby-gravity (MRG), and n = 1 westward inertial gravity (WIG) waves, but not the Madden-Julian Oscillation (MJO) or n = 0 EIG wave. Reduction of cloud-radiative heating has little effect on the phase speed of the waves, which is associated with unchanged effective static stability caused by the near cancellation between reduced dry static stability and reduced diabatic heating. An important implication of this study is that when tuning GCM's top-of-the-atmosphere radiative fluxes to fit the observations, one needs to make sure that the enhancement factor of cloud-radiative heating at the intraseasonal timescale also fits with the observation so that the convectively coupled equatorial waves are not suppressed. C1 [Lin, Jia-Lin] NOAA, ESRL, CIRES, Climate Diagnost Ctr, Boulder, CO USA. [Kim, Daehyun; Kang, In-Sik] Seoul Natl Univ, Dept Atmospher Sci, Seoul 151742, South Korea. [Lee, Myong-In] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. RP Lin, JL (reprint author), Ohio State Univ, Dept Geog, 1105 Derby Hall,154 N Oval Mall, Columbus, OH 43210 USA. EM lin.789@osu.edu RI 안, 민섭/D-9972-2015; OI Lee, Myong-In/0000-0001-8983-8624 NR 58 TC 9 Z9 9 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 27 PY 2007 VL 112 IS D24 AR D24107 DI 10.1029/2006JD008291 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NL UT WOS:000252013600001 ER PT J AU Wyant, MC Bretherton, CS Chlond, A Griffin, BM Kitagawa, H Lappen, CL Larson, VE Lock, A Park, S de Roode, SR Uchida, J Zhao, M Ackerman, AS AF Wyant, Matthew C. Bretherton, Christopher S. Chlond, Andreas Griffin, Brian M. Kitagawa, Hiroto Lappen, Cara-Lyn Larson, Vincent E. Lock, Adrian Park, Sungsu de Roode, Stephan R. Uchida, Junya Zhao, Ming Ackerman, Andrew S. TI A single-column model intercomparison of a heavily drizzling stratocumulus-topped boundary layer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NOCTURNAL MARINE STRATOCUMULUS; SHALLOW CUMULUS CONVECTION; LARGE-EDDY SIMULATION; LARGE-SCALE MODELS; PART I; STRATIFORM CLOUDS; DIURNAL CYCLE; WATER-CONTENT; MIXED LAYER; SCHEME AB This study presents an intercomparison of single-column model simulations of a nocturnal heavily drizzling marine stratocumulus-topped boundary layer. Initial conditions and forcings are based on nocturnal flight observations off the coast of California during the DYCOMS-II field experiment. Differences in turbulent and microphysical parameterizations between models were isolated by slightly idealizing and standardizing the specification of surface and radiative fluxes. For most participating models, the case was run at both typical operational vertical resolution of about 100 m and also at high vertical resolution of about 10 m. As in prior stratocumulus intercomparisons, the simulations quickly develop considerable scatter in liquid water path (LWP) between models. However, the simulated dependence of cloud base drizzle fluxes on LWP in most models is broadly consistent with recent observations. Sensitivity tests with drizzle turned off show that drizzle substantially decreases LWP for many models. The sensitivity of entrainment rate to drizzle is more muted. Simulated LWP and entrainment are also sensitive to the inclusion of cloud droplet sedimentation. Many models underestimate the fraction of drizzle that evaporates below cloud base, which may distort the simulated feedbacks of drizzle on turbulence, entrainment, and LWP. C1 [Wyant, Matthew C.; Bretherton, Christopher S.; Park, Sungsu] Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. [Chlond, Andreas] Max Planck Inst Meteorol, D-20146 Hamburg, Germany. [Griffin, Brian M.; Larson, Vincent E.] Univ Wisconsin, Dept Math Sci, Milwaukee, WI 53201 USA. [Lappen, Cara-Lyn] Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. [Lock, Adrian] Met Off, Exeter EX1 3PB, Devon, England. [de Roode, Stephan R.] Koninklijk Nederlands Meteorol Inst, NL-3730 AE De Bilt, Netherlands. [Uchida, Junya] Univ Washington, Dept Appl Math, Seattle, WA 98195 USA. [Zhao, Ming] NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08540 USA. [Ackerman, Andrew S.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Kitagawa, Hiroto] Japan Meteorol Agcy, Tokyo 1008122, Japan. RP Wyant, MC (reprint author), Univ Washington, Dept Atmospher Sci, Box 351640, Seattle, WA 98195 USA. EM mwyant@atmos.washington.edu RI Ackerman, Andrew/D-4433-2012; de Roode, Stephan/J-8611-2012; Zhao, Ming/C-6928-2014 OI Ackerman, Andrew/0000-0003-0254-6253; de Roode, Stephan/0000-0003-3217-8009; NR 45 TC 26 Z9 26 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 27 PY 2007 VL 112 IS D24 AR D24204 DI 10.1029/2007JD008536 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NL UT WOS:000252013600002 ER PT J AU Fenoglio-Marc, L Kusche, J Becker, M Fukumori, I AF Fenoglio-Marc, L. Kusche, J. Becker, M. Fukumori, I. TI Comment on "On the steric and mass-induced contributions to the annual sea level variations in the Mediterranean Sea'' by David Garcia et al. SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Editorial Material ID TIME-VARIABLE GRAVITY; WATER; TEMPERATURE; GRACE; MODEL C1 [Fenoglio-Marc, L.; Becker, M.] Tech Univ Darmstadt, Inst Phys Geodesy, D-64287 Darmstadt, Germany. [Fukumori, I.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Kusche, J.] Geoforschungszentrum Potsdam, Dept Geodesy & Remote Sensing 1, D-14473 Potsdam, Germany. RP Fenoglio-Marc, L (reprint author), Tech Univ Darmstadt, Inst Phys Geodesy, Petersenstr 13, D-64287 Darmstadt, Germany. EM fenoglio@ipg.tu-darmstadt.de; jkusche@gfz-potsdam.de; fukumori@jpl.nasa.gov RI Kusche, Jurgen/E-9805-2014; Fenoglio-Marc, Luciana/J-3305-2016 OI Kusche, Jurgen/0000-0001-7069-021X; Fenoglio-Marc, Luciana/0000-0003-3701-8426 NR 16 TC 7 Z9 7 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 27 PY 2007 VL 112 IS C12 AR C12018 DI 10.1029/2007JC004196 PG 3 WC Oceanography SC Oceanography GA 246NX UT WOS:000252014800001 ER PT J AU Ajello, JM Stevens, MH Stewart, I Larsen, K Esposito, L Colwell, J McClintock, W Holsclaw, G Gustin, J Pryor, W AF Ajello, Joseph M. Stevens, Michael H. Stewart, Ian Larsen, Kristopher Esposito, Larry Colwell, Josh McClintock, William Holsclaw, Greg Gustin, Jacques Pryor, Wayne TI Titan airglow spectra from Cassini Ultraviolet Imaging Spectrograph (UVIS): EUV analysis SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ELECTRON-IMPACT; EUV EMISSION; MEDIUM-RESOLUTION; CROSS-SECTIONS; N-2; NITROGEN; ATMOSPHERE; BAND; PREDISSOCIATION; DISSOCIATION AB We present the first UV airglow observations of Titan's atmosphere by the Ultraviolet Imaging Spectrograph (UVIS) on Cassini. Using one spectral channel in the EUV from 561-1182 angstrom and one in the FUV from 1115-1913 angstrom, UVIS observed the disk on 13 December, 2004 at low solar activity. The EUV spectrum consists of three band systems of N(2) (b (1)Pi(u), b' (1)Sigma(+)(u), c'(4) (1)Sigma(+)(u) -> X(1)Sigma(+)(g)), while the FUV spectrum consists of one (a (1)Pi(g) -> X (1)Sigma(+)(g)). Both the EUV and FUV spectra contain many NI and N II multiplets that are produced primarily by photodissociative ionization. Spectral intensities of the N(2) c'(4) (1)Sigma(+)(u)(v' = 0) -> X (1)Sigma(+)(g)(v '' = 0 - 2) progression from 950 - 1010 angstrom are resolved for the first time. The UVIS observations reveal that the c'(4) (1)Sigma(+)(u)(0) -> X(1)Sigma(+)(g) (0) vibrational band near 958 angstrom is weak and undetectable, and that N I multiplets near 953.2 and 964.5 angstrom are present instead. Magnetospheric particle excitation may be weak or sporadic, since the nightside EUV spectrum on this orbit shows no observable nitrogen emission features and only H Ly-beta. C1 [Ajello, Joseph M.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Stewart, Ian; Larsen, Kristopher; Esposito, Larry; Colwell, Josh; McClintock, William; Holsclaw, Greg; Gustin, Jacques] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. [Pryor, Wayne] Cent Arizona Coll, Dept Sci, Coolidge, AZ 85228 USA. [Stevens, Michael H.] USN, Res Lab, Div Space Sci, Washington, DC 20375 USA. RP Ajello, JM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jajello@mail.jpl.nasa.gov OI Stevens, Michael/0000-0003-1082-8955 NR 27 TC 36 Z9 36 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 25 PY 2007 VL 34 IS 24 AR L24204 DI 10.1029/2007GL031555 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 246NC UT WOS:000252012700005 ER PT J AU Purucker, M Sabaka, T Le, G Slavin, JA Strangeway, RJ Busby, C AF Purucker, M. Sabaka, T. Le, G. Slavin, J. A. Strangeway, R. J. Busby, C. TI Magnetic field gradients from the ST-5 constellation: Improving magnetic and thermal models of the lithosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANOMALIES; MANTLE AB We report the development of a new technique (magnetic gradiometry) for satellite- based remote sensing of the lithosphere. The measurements reported here represent the first systematic measurements of lithospheric magnetic field gradients, and were collected from a spinning spacecraft. The three-satellite ST-5 mission collected vector magnetic field observations at 300-800+ km altitudes over mid and high-northern latitudes in 2006. Away from the auroral oval, and over the continents, the gradients of the low altitude (< 400 km) total anomaly field are dominated by lithospheric magnetic fields. Using a seismic starting model, and magnetic field observations from ST-5 and other recent satellite missions, we demonstrate how these techniques can be used to improve our knowledge of the processes involved in the thickened crust of the Colorado Plateau and the Sierra Madre Occidental. C1 [Purucker, M.; Sabaka, T.] NASA, Goddard Space Flight Ctr, Raytheon Planetary Geodynam Lab, Greenbelt, MD 20771 USA. [Purucker, M.] Univ Calif Santa Barbara, Dept Earth Sci, Santa Barbara, CA 93106 USA. [Le, G.; Slavin, J. A.] NASA, Goddard Space Flight Ctr, Heliophys Sci Div, Greenbelt, MD 20771 USA. [Strangeway, R. J.] Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. RP Purucker, M (reprint author), NASA, Goddard Space Flight Ctr, Raytheon Planetary Geodynam Lab, Greenbelt, MD 20771 USA. EM purucker@geomag.gsfc.nasa.gov RI Le, Guan/C-9524-2012; Sabaka, Terence/D-5618-2012; Slavin, James/H-3170-2012 OI Le, Guan/0000-0002-9504-5214; Slavin, James/0000-0002-9206-724X NR 16 TC 13 Z9 14 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 25 PY 2007 VL 34 IS 24 AR L24306 DI 10.1029/2007GL031739 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 246NC UT WOS:000252012700006 ER PT J AU von Savigny, C Robert, C Bovensmann, H Burrows, JP Schwartz, M AF von Savigny, C. Robert, C. Bovensmann, H. Burrows, J. P. Schwartz, M. TI Satellite observations of the quasi 5-day wave in noctilucent clouds and mesopause temperatures SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LOWER THERMOSPHERE; PLANETARY-WAVES; AURA SATELLITE; EOS MLS; MESOSPHERE; EUROPE; TRENDS; SCALE AB We report on simultaneous measurements of the westward propagating quasi 5-day wave in the occurrence rate of noctilucent clouds (NLCs) and the temperature field at NLC altitude during the 2005 NLC season in the northern hemisphere. NLCs are detected using SCIAMACHY/ Envisat limb scattering measurements, and the temperature profiles are measured with MLS/Aura. Quasi 5-day wave signatures are clearly identified in both physical and wavelet space. We find good general agreement in the quasi 5-day wave activity of NLC occurrence rates and the mesopause temperature field, indicating that planetary wave signatures in the temperature field are the main driver of corresponding signatures in NLCs. C1 [von Savigny, C.; Robert, C.; Bovensmann, H.; Burrows, J. P.] Univ Bremen, Inst Environm Phys, D-28334 Bremen, Germany. [Schwartz, M.] Jet Prop Lab, Pasadena, CA 91109 USA. RP von Savigny, C (reprint author), Univ Bremen, Inst Environm Phys & Remote Sensing, Otto Hahn Allee 1, D-28334 Bremen, Germany. EM csavigny@iup.physik.uni-bremen.de RI von Savigny, Christian/B-3910-2014; Schwartz, Michael/F-5172-2016; Bovensmann, Heinrich/P-4135-2016; Burrows, John/B-6199-2014 OI Schwartz, Michael/0000-0001-6169-5094; Bovensmann, Heinrich/0000-0001-8882-4108; Burrows, John/0000-0002-6821-5580 NR 20 TC 28 Z9 28 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 25 PY 2007 VL 34 IS 24 AR L24808 DI 10.1029/2007GL030987 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 246NC UT WOS:000252012700002 ER PT J AU Selle, LC Okong'o, NA Bellan, J Harstad, KG AF Selle, Laurent C. Okong'o, Nora A. Bellan, Josette Harstad, Kenneth G. TI Modelling of subgrid-scale phenomena in supercritical transitional mixing layers: an a priori study SO JOURNAL OF FLUID MECHANICS LA English DT Article ID LARGE-EDDY SIMULATION; DIRECT NUMERICAL SIMULATIONS; EVAPORATING DROPS; SHEAR-LAYER; PRESSURE; NITROGEN; TURBULENCE; HEPTANE; HYDROGEN; FLOWS AB A database of transitional direct numerical simulation (DNS) realizations of a supercritical mixing layer is analysed for understanding small-scale behaviour and examining subgrid-scale (SGS) models duplicating that behaviour. Initially, the mixing layer contains a single chemical species in each of the two streams, and a perturbation promotes roll-up and a double pairing of the four spanwise vortices initially present. The database encompasses three combinations of chemical species, several perturbation wavelengths and amplitudes, and several initial Reynolds numbers specifically chosen for the sole purpose of achieving transition. The DNS equations are the Navier-Stokes, total energy and species equations coupled to a real-gas equation of state; the fluxes of species and heat include the Soret and Dufour effects. The large-eddy simulation (LES) equations are derived from the DNS ones through filtering. Compared to the DNS equations, two types of additional terms are identified in the LES equations: SGS fluxes and other terms for which either assumptions or models are necessary. The magnitude of all terms in the LES conservation equations is analysed on the DNS database, with special attention to terms that could possibly be neglected. It is shown that in contrast to atmospheric-pressure gaseous flows, there are two new terms that must be modelled: one in each of the momentum and the energy equations. These new terms can be thought to result from the filtering of the nonlinear equation of state, and are associated with regions of high density-gradient magnitude both found in DNS and observed experimentally in fully turbulent high-pressure flows. A model is derived for the momentum-equation additional term that performs well at small filter size but deteriorates as the filter size increases, highlighting the necessity of ensuring appropriate grid resolution in LES. Modelling approaches for the energy-equation additional term are proposed, all of which may be too computationally intensive in LES. Several SGS flux models are tested on an a priori basis. The Smagorinsky (SM) model has a poor correlation with the data, while the gradient (GR) and scale-similarity (SS) models have high correlations. Calibrated model coefficients for the GR and SS models yield good agreement with the SGS fluxes, although statistically, the coefficients are not valid over all realizations. The GR model is also tested for the variances entering the calculation of the new terms in the momentum and energy equations; high correlations are obtained, although the calibrated coefficients are not statistically significant over the entire database at fixed filter size. As a manifestation of the small-scale supercritical. mixing peculiarities, both scalar-dissipation visualizations and the scalar-dissipation probability density functions (PDF) are examined. The PDF is shown to exhibit minor peaks, with particular significance for those at larger scalar dissipation values than the mean, thus significantly departing from the Gaussian behaviour. C1 [Selle, Laurent C.; Bellan, Josette] CALTECH, Pasadena, CA 91125 USA. [Okong'o, Nora A.; Bellan, Josette; Harstad, Kenneth G.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Selle, LC (reprint author), CALTECH, Pasadena, CA 91125 USA. RI Selle, Laurent/I-6369-2013 OI Selle, Laurent/0000-0002-5997-3646 NR 43 TC 30 Z9 32 U1 0 U2 4 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD DEC 25 PY 2007 VL 593 BP 57 EP 91 DI 10.1017/S0022112007008075 PG 35 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 244BD UT WOS:000251840100003 ER PT J AU Manney, GL Daffer, WH Zawodny, JM Bernath, PF Hoppel, KW Walker, KA Knosp, BW Boone, C Remsberg, EE Santee, ML Harvey, VL Pawson, S Jackson, DR Deaver, L McElroy, CT McLinden, CA Drummond, JR Pumphrey, HC Lambert, A Schwartz, MJ Froidevaux, L McLeod, S Takacs, LL Suarez, MJ Trepte, CR Cuddy, DC Livesey, NJ Harwood, RS Waters, JW AF Manney, Gloria L. Daffer, William H. Zawodny, Joseph M. Bernath, Peter F. Hoppel, Karl W. Walker, Kaley A. Knosp, Brian W. Boone, Chris Remsberg, Ellis E. Santee, Michelle L. Harvey, V. Lynn Pawson, Steven Jackson, David R. Deaver, Lance McElroy, C. Thomas McLinden, Chris A. Drummond, James R. Pumphrey, Hugh C. Lambert, Alyn Schwartz, Michael J. Froidevaux, Lucien McLeod, Sean Takacs, Lawrence L. Suarez, Max J. Trepte, Charles R. Cuddy, David C. Livesey, Nathaniel J. Harwood, Robert S. Waters, Joe W. TI Solar occultation satellite data and derived meteorological products: Sampling issues and comparisons with Aura Microwave Limb Sounder SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID STRATOSPHERIC POLAR VORTEX; DATA ASSIMILATION SCHEME; TRACE GAS OBSERVATIONS; II OZONE MEASUREMENTS; SSI ANALYSIS SYSTEM; SAGE-II; ARCTIC WINTER; POAM-III; POTENTIAL VORTICITY; MIDDLE ATMOSPHERE AB Derived Meteorological Products (DMPs, including potential temperature, potential vorticity (PV), equivalent latitude (EqL), horizontal winds and tropopause locations) from several meteorological analyses have been produced for the locations and times of measurements taken by several solar occultation instruments and the Aura Microwave Limb Sounder (MLS). MLS and solar occultation data are analyzed using DMPs to illustrate sampling issues that may affect interpretation and comparison of data sets with diverse sampling patterns and to provide guidance regarding the kinds of studies that benefit most from analyzing satellite data in relation to meteorological conditions using the DMPs. Using EqL or PV as a vortex-centered coordinate does not alleviate all sampling problems, including those in studies using "vortex averages'' of solar occultation data and in analyses of localized features (such as polar stratospheric clouds) and other fields that do not correlate well with PV. Using DMPs to view measurements with respect to their air mass characteristics is particularly valuable in studies of transport of long-lived trace gases, polar processing in the winter lower stratosphere, and distributions and transport of O-3 and other trace gases from the upper troposphere through the lower stratosphere. The comparisons shown here demonstrate good agreement between MLS and solar occultation data for O-3, N2O, H2O, HNO3, and HCl; small biases are attributable to sampling effects or are consistent with detailed validation results presented elsewhere in this special section. The DMPs are valuable for many scientific studies and to facilitate validation of noncoincident measurements. C1 [Manney, Gloria L.; Knosp, Brian W.; Santee, Michelle L.; Lambert, Alyn; Schwartz, Michael J.; Froidevaux, Lucien; Cuddy, David C.; Livesey, Nathaniel J.; Waters, Joe W.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Manney, Gloria L.] New Mexico Inst Min & Technol, Socorro, NM 87801 USA. [Daffer, William H.] Columbus Technol & Serv Inc, Pasadena, CA 91101 USA. [Zawodny, Joseph M.; Remsberg, Ellis E.; Trepte, Charles R.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Bernath, Peter F.; Walker, Kaley A.; Boone, Chris; McLeod, Sean] Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. [Bernath, Peter F.] Univ York, Dept Chem, York YO10 5DD, N Yorkshire, England. [Hoppel, Karl W.] USN, Res Lab, Washington, DC 20375 USA. [Walker, Kaley A.; Drummond, James R.] Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. [Harvey, V. Lynn] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. [Pawson, Steven; Takacs, Lawrence L.; Suarez, Max J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Jackson, David R.] Met Off, Exeter EX1 3PB, Devon, England. [Deaver, Lance] GATS Inc, Newport News, VA 23606 USA. [McElroy, C. Thomas; McLinden, Chris A.; Harwood, Robert S.] Environm Canada, Toronto, ON M3H 5T4, Canada. [Drummond, James R.] Dalhousie Univ, Dept Phys & Atmospher Sci, Halifax, NS, Canada. [Pumphrey, Hugh C.] Univ Edinburgh, Sch Geosci, Edinburgh EH8 9YL, Midlothian, Scotland. RP Manney, GL (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-701, Pasadena, CA 91109 USA. EM gloria.l.manney@jpl.nasa.gov RI Bernath, Peter/B-6567-2012; McLinden, Chris/A-7710-2010; Drummond, James/O-7467-2014; Schwartz, Michael/F-5172-2016; Pawson, Steven/I-1865-2014 OI Bernath, Peter/0000-0002-1255-396X; McLinden, Chris/0000-0001-5054-1380; Schwartz, Michael/0000-0001-6169-5094; Pawson, Steven/0000-0003-0200-717X NR 108 TC 84 Z9 85 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 25 PY 2007 VL 112 IS D24 AR D24S50 DI 10.1029/2007JD008709 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NK UT WOS:000252013500004 ER PT J AU Xu, JY Smith, AK Yuan, W Liu, HL Wu, Q Mlynczak, MG Russell, JM AF Xu, Jiyao Smith, A. K. Yuan, W. Liu, H. -L. Wu, Qian Mlynczak, M. G. Russell, J. M., III TI Global structure and long-term variations of zonal mean temperature observed by TIMED/SABER SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RESOLUTION DOPPLER IMAGER; REGION 80-105 KM; MESOSPHERIC TEMPERATURE; MIDDLE ATMOSPHERE; MESOPAUSE REGION; SEMIANNUAL OSCILLATION; QUASI-2-DAY WAVE; LOWER THERMOSPHERE; SOLAR-CYCLE; SEASONAL-VARIATION AB In this paper, we present a method of extracting zonal mean temperature and tides from TIMED/SABER satellite and discuss the features of the zonal mean temperature. The global temperature structure is presented, and the mean variations at each latitude and altitude are decomposed into semiannual (SAO), annual (AO), and quasi-biennial (QBO) components. The SAO is strong in the tropical upper stratosphere, mesosphere, and lower thermosphere. The SAO phase (measured by the time of the maximum) is at the equinox at 85 km and at solstice at 75 km. The amplitude is large compared to the annual mean temperature structure, which leads to a mesospheric inversion layer (MIL) in the zonal mean temperature around the equator at equinox. The AO is most evident at middle latitudes and displays a clear hemispheric asymmetry at solstices. The QBO in temperature is strongest in the tropical lower stratosphere; its period there is 26.6 months. There are also weak QBO signals near the mesopause and throughout the middle atmosphere at midlatitudes. The analysis of longer-term variations of the zonal mean temperature, probably affected by the solar cycle but also containing any other trends, indicates that in most regions, the zonal mean temperature decreases during the period of 5 years and is positively correlated with the solar radiation. These results use version 1.06 of the SABER temperature data, which have some known biases in the vicinity of the mesopause. C1 [Xu, Jiyao; Yuan, W.] Chinese Acad Sci, Key Lab Space Weather, Beijing 100080, Peoples R China. [Smith, A. K.] Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. [Liu, H. -L.; Wu, Qian] Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. [Mlynczak, M. G.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Russell, J. M., III] Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Xu, JY (reprint author), Chinese Acad Sci, Key Lab Space Weather, Beijing 100080, Peoples R China. RI Liu, Han-Li/A-9549-2008; Mlynczak, Martin/K-3396-2012 OI Liu, Han-Li/0000-0002-6370-0704; NR 53 TC 42 Z9 46 U1 1 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 25 PY 2007 VL 112 IS D24 AR D24106 DI 10.1029/2007JD008546 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246NK UT WOS:000252013500003 ER PT J AU Kutepov, AA Feofilov, AG Medvedev, AS Pauldrach, AWA Hartogh, P AF Kutepov, Alexander A. Feofilov, Artem G. Medvedev, Alexander S. Pauldrach, Adalbert W. A. Hartogh, Paul TI Small-scale temperature fluctuations associated with gravity waves cause additional radiative cooling of mesopause the region SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PLANETARY-ATMOSPHERES; MIDDLE ATMOSPHERE; CO2; PARAMETERIZATION; GAS AB We present a study of the radiative cooling of the mesosphere and lower thermosphere in the infrared bands of CO2, O-3 and H2O due to small-scale irregular temperature fluctuations caused by gravity waves. These persistent fluctuations are presently not well represented by general circulation models. A statistical model of gravity wave-induced temperature variations was applied to large-scale temperature profiles, and the corresponding direct radiative calculations were performed. We show that temperature fluctuations can cause an additional cooling up to 3 K day(-1) near the mesopause. The effect is produced mainly by the fundamental 15 mu m band of the main CO2 isotope. We found a simple correction depending on the temperature fluctuations variance, which should be added in radiative calculations to the mean temperature profile to account for the additional cooling associated with the unresolved disturbances. C1 [Kutepov, Alexander A.; Pauldrach, Adalbert W. A.] Univ Munich, Fac Phys, Univ Observ Munich, Munich, Germany. [Kutepov, Alexander A.] Catholic Univ Amer, Dept Phys, Washington, DC USA. [Kutepov, Alexander A.; Feofilov, Artem G.] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. [Feofilov, Artem G.] Oak Ridge Associated Univ, Oak Ridge, TN USA. [Medvedev, Alexander S.; Hartogh, Paul] Max Planck Inst Solar Syst Res, Katlenburg Duhm, Germany. RP Kutepov, AA (reprint author), Univ Munich, Fac Phys, Univ Observ Munich, Munich, Germany. RI Feofilov, Artem/A-2271-2015; OI Feofilov, Artem/0000-0001-9924-4846; Medvedev, Alexander/0000-0003-2713-8977 NR 18 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 22 PY 2007 VL 34 IS 24 AR L24807 DI 10.1029/2007GL032392 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 244PK UT WOS:000251877600007 ER PT J AU Lin, X Pielke, RA Hubbard, KG Crawford, KC Shafer, MA Matsui, T AF Lin, X. Pielke, R. A., Sr. Hubbard, K. G. Crawford, K. C. Shafer, M. A. Matsui, T. TI An examination of 1997-2007 surface layer temperature trends at two heights in Oklahoma SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LINEAR TRENDS; TIME-SERIES; CLIMATE; URBAN AB This study assesses near surface lapse rates and temperatures over the past decade at two heights from the Oklahoma Mesonet. A statistically significant change in lapse rate was detected of -0.21 +/- 0.09 degrees C (10 m)(-1) per decade. The trend of nighttime lapse rate was about three times larger than the magnitude of trend of the daytime lapse rate. The lapse rate trends at the time of the daily maximum and minimum temperatures were larger during calm conditions. Significantly, changes of temperature trends at a single height were inconclusive when the data was not segmented by wind speed classes. For daily maximum and minimum station series at two heights, the temperature trends of these station series were the largest for daily minimum temperature at 1.5 m under calm conditions, and the second largest for daily minimum temperatures at 9.0 m under calm conditions. These observations document that monitoring long term near-surface daily minimum temperature trends at a single level on light wind nights will not produce the same trends as for long term temperature trends at other heights near the surface. C1 [Lin, X.; Hubbard, K. G.] Univ Nebraska, High Plains Reg Climate Ctr, Lincoln, NE 68583 USA. [Pielke, R. A., Sr.] Univ Colorado, Cooperat Inst Res Environm Sci, Dept Atmospher Ocean Sci, Boulder, CO 80309 USA. [Crawford, K. C.; Shafer, M. A.] Univ Oklahoma, Oklahoma Climatol Survey, Norman, OK USA. [Matsui, T.] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD USA. [Matsui, T.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD USA. RP Crawford, KC (reprint author), Univ Nebraska, High Plains Reg Climate Ctr, Lincoln, NE 68583 USA. RI Pielke, Roger/A-5015-2009 NR 12 TC 7 Z9 7 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 22 PY 2007 VL 34 IS 24 AR L24705 DI 10.1029/2007GL031652 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 244PK UT WOS:000251877600002 ER PT J AU Maslanik, JA Fowler, C Stroeve, J Drobot, S Zwally, J Yi, D Emery, W AF Maslanik, J. A. Fowler, C. Stroeve, J. Drobot, S. Zwally, J. Yi, D. Emery, W. TI A younger, thinner Arctic ice cover: Increased potential for rapid, extensive sea-ice loss SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OCEAN AB Satellite-derived estimates of sea-ice age and thickness are combined to produce a proxy ice thickness record for 1982 to the present. These data show that in addition to the well-documented loss of perennial ice cover as a whole, the amount of oldest and thickest ice within the remaining multiyear ice pack has declined significantly. The oldest ice types have essentially disappeared, and 58% of the multiyear ice now consists of relatively young 2-and 3-year-old ice compared to 35% in the mid-1980s. Ice coverage in summer 2007 reached a record minimum, with ice extent declining by 42% compared to conditions in the 1980s. The much-reduced extent of the oldest and thickest ice, in combination with other factors such as ice transport that assist the ice-albedo feedback by exposing more open water, help explain this large and abrupt ice loss. C1 [Maslanik, J. A.; Fowler, C.; Drobot, S.; Emery, W.] Univ Colorado, Colorado Ctr Astrodynam Res, Boulder, CO 80309 USA. [Stroeve, J.] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. [Zwally, J.; Yi, D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Maslanik, JA (reprint author), Univ Colorado, Colorado Ctr Astrodynam Res, Boulder, CO 80309 USA. EM james.maslanik@colorado.edu RI Stroeve, Julienne/D-1525-2010; OI Emery, William/0000-0002-7598-9082 NR 21 TC 305 Z9 319 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 22 PY 2007 VL 34 IS 24 AR L24501 DI 10.1029/2007GL032043 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 244PK UT WOS:000251877600006 ER PT J AU Dickerson, RR Li, C Li, Z Marufu, LT Stehr, JW McClure, B Krotkov, N Chen, H Wang, P Xia, X Ban, X Gong, F Yuan, J Yang, J AF Dickerson, R. R. Li, C. Li, Z. Marufu, L. T. Stehr, J. W. McClure, B. Krotkov, N. Chen, H. Wang, P. Xia, X. Ban, X. Gong, F. Yuan, J. Yang, J. TI Aircraft observations of dust and pollutants over northeast China: Insight into the meteorological mechanisms of transport SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPOSPHERIC OZONE; EAST-ASIA; POLLUTION TRANSPORT; AIR-POLLUTANTS; TRANSPACIFIC TRANSPORT; CARBON-MONOXIDE; ATLANTIC-OCEAN; MIXING RATIOS; P EXPERIMENT; TRACE-P AB The meteorological mechanisms for lofting trace gases and aerosols out of the planetary boundary layer (PBL) into the free troposphere are key to understanding local air pollution problems as well as regional and global atmospheric chemistry and climate issues. Over the North American continent, convective storms and lifting in warm conveyor belts transport pollutants into the free troposphere. Little is known about the vertical distribution of pollutants and dust over east Asia, and the processes leading to transport, transformation, and removal of these species remain uncertain. To provide insight into these mechanisms, we report on eight flights based out of Shenyang in NE China as part of the U. S./China EAST-AIRE project conducted in April 2005. We evaluate profiles of trace species, along with back trajectories and satellite data, in the meteorological context of cyclonic systems. The warm-sector PBL air ahead of a cold front was highly polluted, while in the free troposphere concentrations of trace gases and aerosols were lower, but well above background; we measured similar to 300 ppb CO, similar to 2 ppb SO2, similar to 70 ppb O-3, and similar to 8 x 10(-5) m(-1) aerosol scattering between similar to 1000 and 4000 m altitude. Satellite observations indicate that the entire plume contained almost 10 5 tons of SO2 and that the gas decayed with a lifetime of 3-5 d. Roughly the same mass of aerosol was transported into the free troposphere. Over the east Asian continent, dry convection appears to dominate with warm conveyor belts first coming into play as the cyclonic systems move off the coast. C1 [Dickerson, R. R.; Li, C.; Li, Z.; Marufu, L. T.; Stehr, J. W.] Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD 20742 USA. [Dickerson, R. R.; McClure, B.] Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. [Li, Z.; Chen, H.; Wang, P.; Xia, X.] Chinese Acad Sci, Inst Atmospher Phys, Beijing, Peoples R China. [Krotkov, N.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. [Ban, X.; Gong, F.; Yuan, J.] Liaoning Meteorol Bur, Shenyang, Peoples R China. [Yang, J.] Nanjing Univ Informat Sci & Technol, Key Lab Atmospher Phys & Environm, Nanjing, Peoples R China. RP Dickerson, RR (reprint author), Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD 20742 USA. RI Xia, Xiangao/G-5545-2011; Li, Can/F-6867-2011; Stehr, Jeffrey/F-2638-2010; Li, Zhanqing/F-4424-2010; Krotkov, Nickolay/E-1541-2012; Dickerson, Russell/F-2857-2010 OI Xia, Xiangao/0000-0002-4187-6311; Stehr, Jeffrey/0000-0003-4840-6942; Li, Zhanqing/0000-0001-6737-382X; Krotkov, Nickolay/0000-0001-6170-6750; Dickerson, Russell/0000-0003-0206-3083 NR 67 TC 50 Z9 51 U1 3 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 22 PY 2007 VL 112 IS D24 AR D24S90 DI 10.1029/2007JD008999 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 244PX UT WOS:000251878900003 ER PT J AU Tao, WK Li, XW Khain, A Matsui, T Lang, S Simpson, J AF Tao, Wei-Kuo Li, Xiaowen Khain, Alexander Matsui, Toshihisa Lang, Stephen Simpson, Joanne TI Role of atmospheric aerosol concentration on deep convective precipitation: Cloud-resolving model simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MIDLATITUDE SQUALL LINE; TOGA-COARE; PART I; CUMULUS CLOUD; NUMERICAL SIMULATIONS; CONDENSATION NUCLEI; NUCLEATING AEROSOL; SURFACE FLUXES; MICROPHYSICS; SENSITIVITY AB A two-dimensional cloud-resolving model with detailed spectral bin microphysics is used to examine the effect of aerosols on three different deep convective cloud systems that developed in different geographic locations: south Florida, Oklahoma, and the central Pacific. A pair of model simulations, one with an idealized low cloud condensation nuclei (CCN) (clean) and one with an idealized high CCN (dirty environment), is conducted for each case. In all three cases, rain reaches the ground earlier for the low-CCN case. Rain suppression is also evident in all three cases with high CCN. However, this suppression only occurs during the early stages of the simulations. During the mature stages of the simulations the effects of increasing aerosol concentration range from rain suppression in the Oklahoma case to almost no effect in the Florida case to rain enhancement in the Pacific case. The model results suggest that evaporative cooling in the lower troposphere is a key process in determining whether high CCN reduces or enhances precipitation. Stronger evaporative cooling can produce a stronger cold pool and thus stronger low-level convergence through interactions with the low-level wind shear. Consequently, precipitation processes can be more vigorous. For example, the evaporative cooling is more than two times stronger in the lower troposphere with high CCN for the Pacific case. Sensitivity tests also suggest that ice processes are crucial for suppressing precipitation in the Oklahoma case with high CCN. A comparison and review of other modeling studies are also presented. C1 [Tao, Wei-Kuo; Li, Xiaowen; Matsui, Toshihisa; Simpson, Joanne] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. [Li, Xiaowen; Matsui, Toshihisa] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. [Khain, Alexander] Hebrew Univ Jerusalem, Dept Atmospher Sci, Jerusalem, Israel. [Lang, Stephen] Sci Syst & Applicat Inc, Lanham, MD USA. RP Tao, WK (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. NR 83 TC 120 Z9 124 U1 5 U2 31 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 22 PY 2007 VL 112 IS D24 AR D24S18 DI 10.1029/2007JD008728 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 244PX UT WOS:000251878900001 ER PT J AU Khazanov, GV Gamayunov, KV Gallagher, DL Kozyra, JU AF Khazanov, G. V. Gamayunov, K. V. Gallagher, D. L. Kozyra, J. U. TI Reply to comment by R. M. Thorne and R. B. Horne Khazanov et al. [2002] and Khazanov et al. [2006] SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Editorial Material ID ION-CYCLOTRON WAVES; IONOSPHERE-PLASMASPHERE TRANSPORT; RING CURRENT REGION; LOWER-HYBRID WAVES; EARTHS MAGNETOSPHERE; MAGNETIC STORM; GEOMAGNETIC STORMS; ALFVEN WAVES; PROPAGATION; MODEL C1 [Khazanov, G. V.; Gamayunov, K. V.; Gallagher, D. L.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35805 USA. [Kozyra, J. U.] Univ Michigan, Space Phys Lab, Ann Arbor, MI 48109 USA. RP Gamayunov, KV (reprint author), NASA, George C Marshall Space Flight Ctr, 320 Sparkman Dr,Mail Code VP62, Huntsville, AL 35805 USA. EM konstantin.gamayunov@msfc.nasa.gov RI Gamayunov, Konstantin/A-8505-2009 OI Gamayunov, Konstantin/0000-0002-8768-8527 NR 50 TC 10 Z9 10 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 22 PY 2007 VL 112 IS A12 AR A12215 DI 10.1029/2007JA012463 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 244RG UT WOS:000251882400005 ER PT J AU Tanskanen, A Lindfors, A Maatta, A Krotkov, N Herman, J Kaurola, J Koskela, T Lakkala, K Fioletov, V Bernhard, G McKenzie, R Kondo, Y O'Neill, M Slaper, H den Outer, P Bais, AF Tamminen, J AF Tanskanen, Aapo Lindfors, Anders Maatta, Anu Krotkov, Nickolay Herman, Jay Kaurola, Jussi Koskela, Tapani Lakkala, Kaisa Fioletov, Vitali Bernhard, Germar McKenzie, Richard Kondo, Yutaka O'Neill, Michael Slaper, Harry den Outer, Peter Bais, Alkiviadis F. Tamminen, Johanna TI Validation of daily erythemal doses from Ozone Monitoring Instrument with ground-based UV measurement data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ULTRAVIOLET IRRADIANCE MEASUREMENTS; SATELLITE ESTIMATION; SPECTRAL IRRADIANCE; OPTICAL-PROPERTIES; BREWER SPECTRORADIOMETER; TEMPERATURE-DEPENDENCE; INDEX CLIMATOLOGY; UNITED-STATES; ARCTIC HAZE; NEW-ZEALAND AB The Dutch-Finnish Ozone Monitoring Instrument (OMI) on board the NASA EOS Aura spacecraft is a nadir viewing spectrometer that measures solar reflected and backscattered light in a selected range of the ultraviolet and visible spectrum. The instrument has a 2600 km wide viewing swath and it is capable of daily, global contiguous mapping. The Finnish Meteorological Institute and NASA Goddard Space Flight Center have developed a surface ultraviolet irradiance algorithm for OMI that produces noontime surface spectral UV irradiance estimates at four wavelengths, noontime erythemal dose rate (UV index), and the erythemal daily dose. The overpass erythemal daily doses derived from OMI data were compared with the daily doses calculated from the ground-based spectral UV measurements from 18 reference instruments. Two alternative methods for the OMI UV algorithm cloud correction were compared: the plane-parallel cloud model method and the method based on Lambertian equivalent reflectivity. The validation results for the two methods showed some differences, but the results do not imply that one method is categorically superior to the other. For flat, snow-free regions with modest loadings of absorbing aerosols or trace gases, the OMI-derived daily erythemal doses have a median overestimation of 0-10%, and some 60 to 80% of the doses are within +/-20% from the ground reference. For sites significantly affected by absorbing aerosols or trace gases one expects, and observes, bigger positive bias up to 50%. For high-latitude sites the satellite-derived doses are occasionally up to 50% too small because of unrealistically small climatological surface albedo. C1 [Bais, Alkiviadis F.] Aristotle Univ Thessaloniki, Lab Atmospheric Phys, GR-54124 Thessaloniki, Greece. Biospherical Instruments, San Diego, CA 92110 USA. [Slaper, Harry; den Outer, Peter] Natl Inst Publ Hlth & Environm, Radiat Res Lab, NL-3720 BA Bilthoven, Netherlands. [Fioletov, Vitali] Environm Canada, Meteorol Serv Canada, Downsview, ON M3H 5T4, Canada. [Krotkov, Nickolay; Herman, Jay] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Tanskanen, Aapo; Lindfors, Anders; Maatta, Anu; Kaurola, Jussi; Koskela, Tapani; Tamminen, Johanna] Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. [Kondo, Yutaka] Univ Tokyo, Res Ctr Adv Sci & Technol, Div Global Atmospheric Environm, Tokyo 1538904, Japan. [Lakkala, Kaisa] Finnish Meteorol Inst, Arctic Res Ctr, FIN-99600 Sodankyla, Finland. [McKenzie, Richard] NIWA Lauder, Natl Inst Water & Atmospheric Res, Central Otago, New Zealand. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Bais, AF (reprint author), Aristotle Univ Thessaloniki, Lab Atmospheric Phys, GR-54124 Thessaloniki, Greece. RI Lindfors, Anders/C-6727-2012; Kondo, Yutaka/D-1459-2012; Bais, Alkiviadis/D-2230-2009; Tamminen, Johanna/D-7959-2014; Krotkov, Nickolay/E-1541-2012; OI Bais, Alkiviadis/0000-0003-3899-2001; Tamminen, Johanna/0000-0003-3095-0069; Krotkov, Nickolay/0000-0001-6170-6750; Fioletov, Vitali/0000-0002-2731-5956; Herman, Jay/0000-0002-9146-1632 NR 76 TC 58 Z9 59 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 21 PY 2007 VL 112 IS D24 AR D24S44 DI 10.1029/2007JD008830 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 244PV UT WOS:000251878700004 ER PT J AU Kwok, R Cunningham, GF Zwally, HJ Yi, D AF Kwok, R. Cunningham, G. F. Zwally, H. J. Yi, D. TI Ice, Cloud, and land Elevation Satellite (ICESat) over Arctic sea ice: Retrieval of freeboard SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SNOW DEPTH; MOTION; SAR AB Total freeboard (snow and ice) of the Arctic Ocean sea ice cover is derived using Ice, Cloud, and land Elevation Satellite (ICESat) data from two 35-day periods: one during the fall (October-November) of 2005 and the other during the winter (February-March) of 2006. Three approaches are used to identify near-sea-surface tiepoints. Thin ice or open water samples in new openings, typically within 1-2 cm of the sea surface, are used to assess the sea surface estimates. Results suggest that our retrieval procedures could provide consistent freeboard estimates along 25-km segments with uncertainties of better than 7 cm. Basin-scale composites of sea ice freeboard show a clear delineation of the seasonal ice zone in the fall. Overall, the mean freeboards of multiyear (MY) and first-year (FY) ice are 35 cm and 14 cm in the fall, and 43 cm and 27 cm in the winter. The increases of similar to 9 cm and similar to 12 cm on MY and FY sea ice are associated with the 4 months of ice growth and snow accumulation between data acquisitions. Since changes in snow depth account for >90% of the seasonal increase in freeboard on MY ice, it dominates the seasonal signal. Our freeboard estimates are within 10 cm of those derived from available snow/ice thickness measurements from ice mass balance buoys. Examination of the two residual elevations fields, after the removal of the sea ice freeboard contribution, shows coherent spatial patterns with a standard deviation (S. D.) of similar to 23 cm. Differencing them reduces the variance and gives a near random field with a mean of similar to 2 cm and a standard deviation of similar to 14 cm. While the residual fields seem to be dominated by the static component of unexplained sea surface height and mean dynamic topography (S.D. similar to 23 cm), the difference field reveals the magnitude of the time-varying components as well as noise in the ICESat elevations (S. D. similar to 10 cm). C1 [Kwok, R.; Cunningham, G. F.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Zwally, H. J.] NASA, Goddard Space Flight Ctr, Cryospher Sci Branch, Greenbelt, MD 20771 USA. [Yi, D.] NASA, Goddard Space Flight Ctr, SGT Inc, Greenbelt, MD 20771 USA. RP Kwok, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 20 TC 65 Z9 68 U1 0 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 21 PY 2007 VL 112 IS C12 AR C12013 DI 10.1029/2006JC003978 PG 19 WC Oceanography SC Oceanography GA 244QL UT WOS:000251880300002 ER PT J AU Kwok, R Comiso, JC Martin, S Drucker, R AF Kwok, R. Comiso, J. C. Martin, S. Drucker, R. TI Ross Sea polynyas: Response of ice concentration retrievals to large areas of thin ice SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID FRAZIL ICE; AMSR-E; THICKNESS; IMAGERY; TEMPERATURE; MOTION; SHELF; BAY AB For a 3-month period between May and July of 2005, we examine the response of the Advanced Microwave Scanning Radiometer ( AMSR-E) Enhanced NASA Team 2 (NT2) and AMSR-E Bootstrap (ABA) ice concentration algorithms to large areas of thin ice of the Ross Sea polynyas. Coincident Envisat Synthetic Aperture Radar (SAR) coverage of the region during this period offers a detailed look at the development of the polynyas within several hundred kilometers of the ice front. The high-resolution imagery and derived ice motion fields show bands of polynya ice, covering up to similar to 105 km(2) of the Ross Sea, that are associated with wind-forced advection. In this study, ice thickness from AMSR-E 36 GHz polarization information serves as the basis for examination of the response. The quality of the thickness of newly formed sea ice (< 10 cm) from AMSR-E is first assessed with thickness estimates derived from ice surface temperatures from the Moderate Resolution Imaging Spectroradiometer ( MODIS) instrument. The effect of large areas of thin ice in lowering the ice concentration estimates from both NT2/ABA approaches is clearly demonstrated. Results show relatively robust relationships between retrieved ice concentrations and thin ice thickness estimates that differ between the two algorithms. These relationships define the approximate spatial coincidence of ice concentration and thickness isopleths. Using the 83% ( ABA) and 91% ( NT2) isopleths as polynya boundaries, we show that the computed coverage compares well with that using the estimated 10-cm thickness contour. The thin ice response characterized here suggests that in regions with polynyas, the retrieval results could be used to provide useful geophysical information, namely thickness and coverage. C1 [Kwok, R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Comiso, J. C.] NASA, Goddard Space Flight Ctr, Cryospher Sci Branch, Greenbelt, MD 20771 USA. [Martin, S.; Drucker, R.] Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. RP Kwok, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 23 TC 29 Z9 29 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 21 PY 2007 VL 112 IS C12 AR C12012 DI 10.1029/2006JC003967 PG 13 WC Oceanography SC Oceanography GA 244QL UT WOS:000251880300001 ER PT J AU Boynton, WV Taylor, GJ Evans, LG Reedy, RC Starr, R Janes, DM Kerry, KE Drake, DM Kim, KJ Williams, RMS Crombie, MK Dohm, JM Baker, V Metzger, AE Karunatillake, S Keller, JM Newsom, HE Arnold, JR Bruckner, J Englert, PAJ Gasnault, O Sprague, AL Mitrofanov, I Squyres, SW Trombka, JI d'Uston, L Wanke, H Hamara, DK AF Boynton, W. V. Taylor, G. J. Evans, L. G. Reedy, R. C. Starr, R. Janes, D. M. Kerry, K. E. Drake, D. M. Kim, K. J. Williams, R. M. S. Crombie, M. K. Dohm, J. M. Baker, V. Metzger, A. E. Karunatillake, S. Keller, J. M. Newsom, H. E. Arnold, J. R. Brueckner, J. Englert, P. A. J. Gasnault, O. Sprague, A. L. Mitrofanov, I. Squyres, S. W. Trombka, J. I. d'Uston, L. Waenke, H. Hamara, D. K. TI Concentration of H, Si, Cl, K, Fe, and Th in the low- and mid-latitude regions of Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID GAMMA-RAY SPECTROMETER; MERIDIANI-PLANUM; MARTIAN SURFACE; NUCLIDE PRODUCTION; GUSEV CRATER; ODYSSEY; SOILS; ROCKS; PATHFINDER; CHEMISTRY AB We report maps of the concentrations of H, Si, Cl, K, Fe, and Th as determined by the Gamma Ray Spectrometer (GRS) on board the 2001 Mars Odyssey Mission for +/-similar to 45 degrees latitudes. The procedures by which the spectra are processed to yield quantitative concentrations are described in detail. The concentrations of elements determined over the locations of the various Mars landers generally agree well with the lander values except for Fe, although the mean of the GRS Fe data agrees well with that of Martian meteorites. The water-equivalent concentration of hydrogen by mass varies from about 1.5% to 7.5% (by mass) with the most enriched areas being near Apollinaris Patera and Arabia Terra. Cl shows a distribution similar to H over the surface except that the Cl content over Medusae Fossae is much greater than elsewhere. The map of Fe shows enrichment in the northern lowlands versus the southern highlands. Silicon shows only very modest variation over the surface with mass fractions ranging from 19% to 22% over most of the planet, though a significant depletion in Si is noted in a region west of Tharsis Montes and Olympus Mons where the Si content is as low as 18%. K and Th show a very similar pattern with depletions associated with young volcanic deposits and enrichments associated with the TES Surface Type-2 material. It is noted that there appears to be no evidence of significant globally distributed thick dust deposits of uniform composition. C1 [Boynton, W. V.; Janes, D. M.; Kerry, K. E.; Kim, K. J.; Williams, R. M. S.; Crombie, M. K.; Keller, J. M.; Sprague, A. L.; Hamara, D. K.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. [Taylor, G. J.; Englert, P. A. J.] Univ Hawaii Manoa, Inst Geophys & Planetol, Honolulu, HI 96822 USA. [Evans, L. G.] Comp Sci Corp, Sci Programs, Lanham, MD USA. [Reedy, R. C.; Kim, K. J.; Newsom, H. E.] Univ New Mexico, Inst Meteorit, Albuquerque, NM 87131 USA. [Starr, R.] Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. [Drake, D. M.] TechSource, Santa Fe, NM USA. [Dohm, J. M.; Baker, V.] Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ USA. [Metzger, A. E.] CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. [Karunatillake, S.; Squyres, S. W.] Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY USA. [Keller, J. M.] Calif State Polytech Univ Pomona, Dept Phys, San Luis Obispo, CA USA. [Arnold, J. R.] Univ Calif San Diego, Dept Chem, La Jolla, CA 92093 USA. [Brueckner, J.; Waenke, H.] Max Planck Inst Chem, D-55128 Mainz, Germany. [Gasnault, O.; d'Uston, L.] CNRS, Ctr Detude Spatiale Rayonnements, UPS, Toulouse, France. [Mitrofanov, I.] Inst Space Res, Moscow, Russia. [Trombka, J. I.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Boynton, WV (reprint author), Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. RI Karunatillake, Suniti/A-5934-2009; Gasnault, Olivier/F-4327-2010; Evans, Larry/F-7462-2012; Dohm, James/A-3831-2014; OI Karunatillake, Suniti/0000-0001-9891-1432; Gasnault, Olivier/0000-0002-6979-9012; Kim, Kyeong J/0000-0001-6220-8411; Reedy, Robert/0000-0002-2189-1303 NR 85 TC 79 Z9 80 U1 5 U2 25 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 21 PY 2007 VL 112 IS E12 AR E12S99 DI 10.1029/2007JE002887 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 244QT UT WOS:000251881100001 ER PT J AU Casassus, S Nyman, LA Dickinson, C Pearson, TJ AF Casassus, S. Nyman, L. -A. Dickinson, C. Pearson, T. J. TI A centimetre-wave excess over free-free emission in planetary nebulae SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE radiation mechanisms : general; planetary nebulae : general; radio continuum : ISM; submillimetre ID RADIO-SYNTHESIS OBSERVATIONS; COSMIC BACKGROUND IMAGER; CONTINUUM OBSERVATIONS; CENTRAL STARS; ABSORPTION-COEFFICIENTS; INTERSTELLAR-MEDIUM; MERLIN POLARIMETRY; METALLIC NEEDLES; MAGNETIC-FIELDS; GAUNT FACTORS AB We report a centimetre-wave (cm-wave, 5-31 GHz) excess over free-free emission in planetary nebulae (PNe). Accurate 31- and 250-GHz measurements show that the 31-GHz flux densities in our sample are systematically higher than the level of optically thin free-free continuum extrapolated from 250-GHz. The 31-GHz excess is observed, within one standard deviation, in all 18 PNe with reliable 31- and 250-GHz data, and is significant in nine PNe. The only exception is the peculiar object M2-9, whose radio spectrum is that of an optically thick stellar wind. On average the fraction of non-free-free emission represents 51 per cent of the total flux density at 31 GHz, with a scatter of 11 per cent. The average 31-250 GHz spectral index of our sample is = -0.43 +/- 0.03 (in flux density, with a scatter of 0.14). The 31-250 GHz drop is reminiscent of the anomalous foreground observed in the diffuse interstellar medium (ISM) by cosmic microwave background (CMB) anisotropy experiments. The 5-31 GHz spectral indices are consistent with both flat spectra and spinning dust emissivities, given the 10 per cent calibration uncertainty of the comparison 5-GHz data. However, a detailed study of the objects with the largest cm-excess, including the low-frequency data available in the literature, shows that present spinning dust models alone cannot explain the cm-wave excess in PNe. Although we have no definitive interpretation of our data, the least implausible explanation involves a synchrotron component absorbed by a cold nebular screen. We give flux densities for 37 objects at 31 GHz, and for 26 objects at 250 GHz. C1 [Casassus, S.] Univ Chile, Dept Astron, Santiago, Chile. [Nyman, L. -A.] European So Observ, Santiago 19, Chile. [Nyman, L. -A.] Onsala Space Observ, S-43992 Onsala, Sweden. [Dickinson, C.; Pearson, T. J.] CALTECH, Chajnantor Observ, Pasadena, CA 91125 USA. [Dickinson, C.] Jet Propuls Lab, Pasadena, CA 91109 USA. RP Casassus, S (reprint author), Univ Chile, Dept Astron, Casilla 36D, Santiago, Chile. EM simon@das.uchile.cl RI Pearson, Timothy/N-2376-2015; Casassus, Simon/I-8609-2016 OI Pearson, Timothy/0000-0001-5213-6231; NR 90 TC 24 Z9 24 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD DEC 21 PY 2007 VL 382 IS 4 BP 1607 EP 1622 DI 10.1111/j.1365-2966.2007.12366.x PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 241QY UT WOS:000251672100016 ER PT J AU Moiseev, AA Deering, PL Hartman, RC Johnson, TE Nebel, TR Ormes, JF Thompson, DJ AF Moiseev, A. A. Deering, P. L. Hartman, R. C. Johnson, T. E. Nebel, T. R. Ormes, J. F. Thompson, D. J. TI High efficiency plastic scintillator detector with wavelength-shifting fiber readout for the GLAST Large Area Telescope SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE GLAST; ACD; anti-coincidence; plastic scintillator; WLS fibers ID ENGINEERING MODEL; BEAM TEST; CALORIMETER; UPGRADE AB This paper describes the design and performance studies of the scintillator tile detectors for the anti-coincidence detector (ACD) of the Large Area Telescope (LAT) on the Gamma ray Large Area Space Telescope (GLAST), scheduled for launch in early 2008. The scintillator tile detectors utilize wavelength-shifting fibers and have dual-photomultiplier-tube readout. The design requires highly efficient and uniform detection of singly charged relativistic particles over the tile area and must meet all requirements for a launch, as well as operation in a space environment. We present here the design of three basic types of tiles used in the ACD, ranging in size from similar to 450 to similar to 2500 cm(2), all similar to 1cm thick, with different shapes, and with photoelectron yield of similar to 20 photoelectrons per minimum ionizing particle at normal tile incidence, uniform over the tile area. Some tiles require flexible clear fiber cables up to 1.5m long to deliver scintillator light to remotely located photomultiplier tubes. (c) 2007 Elsevier B.V. All rights reserved. C1 [Moiseev, A. A.] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, CRESST, Greenbelt, MD 20771 USA. [Deering, P. L.; Nebel, T. R.] Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. [Hartman, R. C.; Johnson, T. E.; Thompson, D. J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Ormes, J. F.] Univ Denver, Denver, CO 80208 USA. RP Moiseev, AA (reprint author), NASA, Goddard Space Flight Ctr, Astrophys Sci Div, CRESST, Greenbelt, MD 20771 USA. EM Alexander.A.Moiseev@nasa.gov RI Thompson, David/D-2939-2012 OI Thompson, David/0000-0001-5217-9135 NR 16 TC 8 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 21 PY 2007 VL 583 IS 2-3 BP 372 EP 381 DI 10.1016/j.nima.2007.09.040 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 244JC UT WOS:000251861200019 ER PT J AU Bennett, VC Brandon, AD Nutman, AP AF Bennett, Vickie C. Brandon, Alan D. Nutman, Allen P. TI Coupled Nd-142-Nd-143 isotopic evidence for Hadean mantle dynamics SO SCIENCE LA English DT Article ID EARLY EARTH DIFFERENTIATION; SOUTHERN WEST GREENLAND; ND-142 EVIDENCE; GNEISS COMPLEX; MAGMA OCEAN; NUUK REGION; EVOLUTION; NEODYMIUM; SYSTEMATICS; CRUST AB The oldest rocks-3.85 billion years old- from southwest Greenland have coupled neodymium- 142 excesses ( from decay of now- extinct samarium- 146; half- life, 103 million years) and neodymium- 143 excesses ( from decay of samarium- 147; half- life, 106 billion years), relative to chondritic meteorites, that directly date the formation of chemically distinct silicate reservoirs in the first 30 million to 75 million years of Earth history. The differences in Nd-142 signatures of coeval rocks from the two most extensive crustal relicts more than 3.6 billion years old, in Western Australia and southwest Greenland, reveal early-formed large- scale chemical heterogeneities in Earth's mantle that persisted for at least the first billion years of Earth history. Temporal variations in Nd-142 signatures track the subsequent incomplete remixing of very- early- formed mantle chemical domains. C1 Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 0200, Australia. Lunar & Planetary Inst, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China. RP Bennett, VC (reprint author), Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 0200, Australia. EM vickie.bennett@anu.edu.au NR 29 TC 106 Z9 109 U1 0 U2 20 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 21 PY 2007 VL 318 IS 5858 BP 1907 EP 1910 DI 10.1126/science.1145928 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 243HE UT WOS:000251786600054 PM 18096803 ER PT J AU Marshall, PJ Treu, T Melbourne, J Gavazzi, R Bundy, K Ammons, SM Bolton, AS Burles, S Larkin, JE Le Mignant, D Koo, DC Koopmans, LVE Max, CE Moustakas, LA Steinbring, E Wright, SA AF Marshall, Philip J. Treu, Tommaso Melbourne, Jason Gavazzi, Raphael Bundy, Kevin Ammons, S. Mark Bolton, Adam S. Burles, Scott Larkin, James E. Le Mignant, David Koo, David C. Koopmans, Leon V. E. Max, Claire E. Moustakas, Leonidas A. Steinbring, Eric Wright, Shelley A. TI Superresolving distant galaxies with gravitational telescopes: Keck laser guide star adaptive optics and Hubble Space Telescope imaging of the lens system SDSS J0737+3216 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : fundamental parameters; gravitational lensing; instrumentation : adaptive optics; methods : data analysis; techniques : high angular resolution ID COMPACT BLUE GALAXIES; HIGH-REDSHIFT GALAXIES; LARGE-SCALE STRUCTURE; DISK GALAXIES; DARK-MATTER; DEEP FIELD; ACS SURVEY; SURFACE-BRIGHTNESS; FUNDAMENTAL PLANE; SIZE EVOLUTION AB We combine high-resolution images in four optical/infrared bands, obtained with the laser guide star adaptive optics ( LGSAO) system on the Keck telescope and with the Hubble Space Telescope ( HST), to study the gravitational lens system SDSS J0737 + 3216 ( lens redshift 0.3223, source redshift 0.5812). We show that ( under favorable observing conditions) ground-based images are comparable to those obtained with HST in terms of precision in the determination of the parameters of both the lens mass distribution and the background source. We also quantify the systematic errors associated with both the incomplete knowledge of the PSF and the uncertain process of lens galaxy light removal and find that similar accuracy can be achieved with Keck LGSAO as with HST. We then exploit this well-calibrated combination of optical and gravitational telescopes to perform a multiwavelength study of the source galaxy at 0.01 '' effective resolution. We find the Sersic index to be indicative of a disklike object, but the measured half-light radius (r(e) = 0.59 +/- 0.007 stat +/- 0.1 sys kpc) and stellar mass (M* = 2.0 +/- 1.0 stat +/- 0.8 sys x 10(9) M(circle dot)) place it more than 3 sigma away from the local disk size-mass relation. The SDSS J0737 + 3216 source has the characteristics of the most compact faint blue galaxies studied and comparable size and mass to dwarf early-type galaxies in the local universe. With the aid of gravitational telescopes to measure individual objects' brightness profiles to 10% accuracy, the study of the high-redshift size-mass relation may be extended by an order of magnitude or more beyond existing surveys at the low-mass end, thus providing a new observational test of galaxy formation models. C1 [Marshall, Philip J.; Treu, Tommaso; Gavazzi, Raphael] Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. [Melbourne, Jason; Ammons, S. Mark; Koo, David C.; Max, Claire E.] Univ Calif Santa Cruz, Lick Observ, UCO, Santa Cruz, CA 95064 USA. [Melbourne, Jason; Ammons, S. Mark; Le Mignant, David] Univ Calif Santa Cruz, Ctr Adapt Opt, Santa Cruz, CA 95064 USA. [Bundy, Kevin] Univ Toronto, Dept Astron & Astrophys, Toronto, ON M5S 3H4, Canada. [Bolton, Adam S.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Burles, Scott] MIT, Kavli Inst Astrophys & Space Res, Dept Phys, Cambridge, MA 02139 USA. [Larkin, James E.; Wright, Shelley A.] Univ Calif Los Angeles, Div Astron & Astrophys, Los Angeles, CA 90095 USA. [Le Mignant, David] W M Keck Observ, Kamuela, HI 96743 USA. [Koopmans, Leon V. E.] Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. [Moustakas, Leonidas A.] CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. [Steinbring, Eric] Herzberg Inst Astrophys, Victoria, BC V9E 2E7, Canada. RP Marshall, PJ (reprint author), Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. EM pjm@physics.ucsb.edu OI Wright, Shelley/0000-0003-1034-8054; Moustakas, Leonidas/0000-0003-3030-2360 NR 61 TC 46 Z9 46 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 1196 EP 1211 DI 10.1086/523091 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600011 ER PT J AU Oesch, PA Stiavelli, M Carollo, CM Bergeron, LE Koekemoer, AM Lucas, RA Pavlovsky, CM Trenti, M Lilly, SJ Beckwith, SVW Dahlen, T Ferguson, HC Gardner, JP Lacey, C Mobasher, B Panagia, N Rix, HW AF Oesch, P. A. Stiavelli, M. Carollo, C. M. Bergeron, L. E. Koekemoer, A. M. Lucas, R. A. Pavlovsky, C. M. Trenti, M. Lilly, S. J. Beckwith, S. V. W. Dahlen, T. Ferguson, H. C. Gardner, Jonathan P. Lacey, C. Mobasher, B. Panagia, N. Rix, H. -W. TI The UDF05 follow-up of the Hubble Ultra Deep Field. I. The faint-end slope of the Lyman break galaxy population at z similar to 5 SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; galaxies : evolution; galaxies : formation; galaxies : high-redshift; galaxies : luminosity function, mass function ID ULTRAVIOLET LUMINOSITY DENSITY; STAR-FORMING GALAXIES; COLD DARK-MATTER; HIGH-REDSHIFT; FORMATION MODELS; EVOLUTION; UNIVERSE; DUST; SIMULATION; SPECTRA AB We present the UDF05 HST program, which consists of three disjoint fields - NICP12, NICP34, plus the HUDF - with deep ACS (F606W, F775W, and F850LP) and NICMOS (F110W and F160W) imaging. Here we use the ACS data for the NICP12 and HUDF fields to implement a (V - i)-(i - z) selection criterion that allows us to identify a sample of 101 (133) z similar to 5 Lyman break galaxies (LBGs) down to z(850) = 28.5 (29.25) mag in NICP12 (HUDF). We construct the rest-frame 1400 angstrom LBG luminosity function (LF) over the range M-1400 = [-21.4, -17.1], i.e. down to similar to 0.04L(*) at z similar to 5, and use Subaru Deep Field results (Yoshida et al. 2006) to constrain our LF at the bright end (M-1400 >= -22.2). We show that (1) different assumptions regarding the LBG SED distribution, dust properties, and intergalactic absorption result in a 25% variation in the number density of LBGs at z similar to 5; (2) under consistent assumptions for dust properties and intergalactic absorption, the HUDF is similar to 30% underdense in z similar to 5 LBGs relative to the NICP12 field, a variation which is well explained by cosmic variance; and (3) the faint-end slope of the LF does not depend on the input parameters, and has a value of alpha similar to -1.6, similar to the faint-end slope of the LF of z similar to 3 and z similar to 6 LBGs. Our study therefore supports no variation in the faint end of the LBG LF over the whole redshift range z similar to 3 to z similar to 6. Based on a comparison with semianalytical models, we speculate that the z similar to 5 LBGs might have a top-heavy IMF. C1 [Oesch, P. A.; Carollo, C. M.; Lilly, S. J.] ETH, Inst Astrophys, CH-8093 Zurich, Switzerland. [Stiavelli, M.; Bergeron, L. E.; Koekemoer, A. M.; Lucas, R. A.; Pavlovsky, C. M.; Trenti, M.; Beckwith, S. V. W.; Dahlen, T.; Ferguson, H. C.; Mobasher, B.; Panagia, N.] Space Telescope Sci Inst, Baltimore, MD 21218 USA. [Stiavelli, M.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Gardner, Jonathan P.] NASA, Goddard Space Flight Ctr, Lab Observ Cosmol, Greenbelt, MD 20771 USA. [Lacey, C.] Univ Durham, Inst Computat Cosmol, Dept Phys, Durham DH1 3LE, England. [Panagia, N.] Osserv Astrofis Catania, INAF, I-95123 Catania, Italy. [Panagia, N.] Supernova Ltd, Virgin Gorda, British Virgin, W Ind Assoc St. [Rix, H. -W.] Max Planck Inst Astron, D-69117 Heidelberg, Germany. RP Oesch, PA (reprint author), ETH, Inst Astrophys, CH-8093 Zurich, Switzerland. EM poesch@phys.ethz.ch OI Oesch, Pascal/0000-0001-5851-6649; Koekemoer, Anton/0000-0002-6610-2048 NR 59 TC 68 Z9 69 U1 0 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 1212 EP 1226 DI 10.1086/522423 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600012 ER PT J AU Dawson, S Rhoads, JE Malhotra, S Stern, D Wang, J Dey, A Spinrad, H Jannuzi, BT AF Dawson, Steve Rhoads, James E. Malhotra, Sangeeta Stern, Daniel Wang, JunXian Dey, Arjun Spinrad, Hyron Jannuzi, Buell T. TI A luminosity function of Ly alpha-emitting galaxies at z approximate to 4.5 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; early universe; galaxies : evolution; galaxies : formation; galaxies : high-redshift ID SUBARU DEEP FIELD; LYMAN-BREAK GALAXIES; PROBE WMAP OBSERVATIONS; HIGH-REDSHIFT GALAXIES; SPECTROSCOPIC CONFIRMATION; Z-SIMILAR-TO-6 QUASARS; RADIATIVE-TRANSFER; KECK SPECTROSCOPY; CLUMPY UNIVERSE; EMITTERS AB We present a catalog of 59 z approximate to 4.5 Ly alpha-emitting galaxies spectroscopically confirmed in a campaign of Keck DEIMOS follow-up observations to candidates selected in the Large Area Ly alpha ( LALA) narrowband imaging survey. We targeted 97 candidates for spectroscopic follow-up; by accounting for the variety of conditions under which we performed spectroscopy, we estimate a selection reliability of similar to 76%. Together with our previous sample of Keck LRIS confirmations, the 59 sources confirmed herein bring the total catalog to 73 spectroscopically confirmed z approximate to 4.5 Ly alpha-emitting galaxies in the approximate to 0.7 deg(2) covered by the LALA imaging. As with the Keck LRIS sample, we find that a nonnegligible fraction of the confirmed Ly alpha lines have rest-frame equivalent widths (W-lambda(rest)) that exceed the maximum predicted for normal stellar populations: 17%-31%( 93% confidence) of the detected galaxies show W-lambda(rest) > 190 angstrom, and 12%-27% ( 90% confidence) show W-lambda(rest) > 240 angstrom. We construct a luminosity function of z approximate to 4.5 Ly alpha emission lines for comparison to Ly alpha luminosity functions spanning 3.1 < z < 6.6. We find no significant evidence for Ly alpha luminosity function evolution from z approximate to 3 to z approximate to 6. This result supports the conclusion that the intergalactic medium remains largely reionized from the local universe out to z approximate to 6.5. It is somewhat at odds with the pronounced drop in the cosmic star formation rate density recently measured between z similar to 3 and z similar to 6 in continuum-selected Lyman-break galaxies, and therefore potentially sheds light on the relationship between the two populations. C1 [Dawson, Steve; Spinrad, Hyron] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. [Rhoads, James E.; Malhotra, Sangeeta] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. [Stern, Daniel] CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. [Wang, JunXian] Univ Sci & Technol China, Ctr Astrophys, Hefei 230026, Peoples R China. [Dey, Arjun; Jannuzi, Buell T.] Kitt Peak Natl Observ, Natl Opt Astron Observ, Tucson, AZ 85726 USA. RP Dawson, S (reprint author), Univ Calif Berkeley, Dept Astron, Mail Code 3411, Berkeley, CA 94720 USA. EM sdawson@astro.berkeley.edu; james.rhoads@asu.edu; sangeeta.malhotra@asu.edu; stern@zwolfkinder.jpl.nasa.gov; jxw@ustc.edu.cn; dey@noao.edu; spinrad@astro.berkeley.edu; jannuzi@noao.edu NR 94 TC 73 Z9 73 U1 0 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 1227 EP 1240 DI 10.1086/522908 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600013 ER PT J AU Evans, DA Lee, JC Turner, TJ Weaver, KA Marshall, HL AF Evans, Daniel A. Lee, Julia C. Turner, T. Jane Weaver, Kimberly A. Marshall, Herman L. TI Probing unification with Chandra HETGS and XMM-Newton EPIC and RGS spectroscopy of the narrow emission line galaxy NGC 2110 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 2110); galaxies : Seyfert ID ACTIVE GALACTIC NUCLEI; X-RAY-ABSORPTION; SEYFERT-GALAXIES; SPECTRA; REFLECTION; NGC-1068; IRON; AGN; DISTRIBUTIONS; QUASARS AB We present results from Chandra HETGS (250 ks over two epochs) and XMM-Newton EPIC and RGS (60 ks) observations of NGC 2110, which has been historically classified as a narrow emission line galaxy. Our results support the interpretation that the source is a Seyfert 2 viewed through a patchy absorber. The nuclear X-ray spectrum of the source is best described by a power law of photon index Gamma similar to 1.7, modified by absorption from multiple layers of neutral material at a large distance from the central supermassive black hole. We report the strong detections of Fe K alpha and Si K alpha lines, which are marginally resolved with the Chandra HETGS, and we constrain the emission radius of the fluorescing material to greater than or similar to 1 pc. There is some evidence for modest additional broadening at the base of the narrow Fe K alpha core with a velocity similar to 4500 km s(-1). We find tentative evidence for ionized emission (O VIII Ly alpha, an O VIII RRC feature, and possibly a Ne IX forbidden line) in the Chandra MEG and XMM-Newton RGS spectra, which could be associated with the known extended X-ray emission that lies similar to 160 pc from the nucleus. We suggest that the 10(23) cm(-2) partially covering absorber originates in broad-line region clouds in the vicinity of the AGN, and that the 3 x 10(22) cm(-2) coverer is likely to have a more distant origin and have a flattened geometry in order to allow the small-scale radio jet to escape. C1 [Evans, Daniel A.; Lee, Julia C.] Harvard Univ, Dept Astron, Cambridge, MA 02138 USA. [Evans, Daniel A.; Lee, Julia C.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Turner, T. Jane; Weaver, Kimberly A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Turner, T. Jane] Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. [Marshall, Herman L.] MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. RP Evans, DA (reprint author), Harvard Univ, Dept Astron, 60 Garden St, Cambridge, MA 02138 USA. RI Lee, Julia/G-2381-2015 OI Lee, Julia/0000-0002-7336-3588 NR 32 TC 16 Z9 16 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 1345 EP 1354 DI 10.1086/523037 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600023 ER PT J AU Taylor, GB Healey, SE Helmboldt, JF Tremblay, S Fassnacht, CD Walker, RC Sjouwerman, LO Pearson, TJ Readhead, ACS Weintraub, L Gehrels, N Romani, RW Michelson, PF Blandford, RD Cotter, G AF Taylor, G. B. Healey, S. E. Helmboldt, J. F. Tremblay, S. Fassnacht, C. D. Walker, R. C. Sjouwerman, L. O. Pearson, T. J. Readhead, A. C. S. Weintraub, L. Gehrels, N. Romani, R. W. Michelson, P. F. Blandford, R. D. Cotter, G. TI Characteristics of EGRET blazars in the VLBA Imaging and Polarimetry Survey (VIPS) SO ASTROPHYSICAL JOURNAL LA English DT Article DE catalogs; galaxies : active; galaxies : jets; galaxies : nuclei; radio continuum : galaxies; surveys; techniques : image processing ID ACTIVE GALACTIC NUCLEI; BL-LACERTAE OBJECTS; LINE ARRAY OBSERVATIONS; SPECTRUM RADIO-SOURCES; GAMMA-RAY SOURCES; ALL-SKY SURVEY; RELATIVISTIC JETS; DETECTED QUASARS; MULTIEPOCH; CATALOG AB We examine the radio properties of EGRET-detected blazars observed as part of the VLBA Imaging and Polarimetry Survey (VIPS). VIPS has a flux limit roughly an order of magnitude below the MOJAVE survey and most other samples that have been used to study the properties of EGRET blazars. At lower flux levels, radio flux density does not directly correlate with gamma-ray flux density. We do find that the EGRET-detected blazars tend to have higher brightness temperatures, greater core fractions, and possibly larger than average jet opening angles. A weak correlation is also found with jet length and with polarization. All of the well-established trends can be explained by systematically larger Doppler factors in the gamma-ray-loud blazars, consistent with the measurements of higher apparent velocities found in monitoring programs carried out at radio frequencies above 10 GHz. C1 [Taylor, G. B.; Tremblay, S.] Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. [Healey, S. E.; Romani, R. W.; Michelson, P. F.] Stanford Univ, Dept Phys, Stanford, CA 94305 USA. [Helmboldt, J. F.] Naval Res Lab, Washington, DC 20375 USA. [Fassnacht, C. D.] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. [Walker, R. C.; Sjouwerman, L. O.] Natl Radio Astron Observ, Socorro, NM 87801 USA. [Pearson, T. J.; Readhead, A. C. S.] CALTECH, Dept Astron, Pasadena, CA 91125 USA. [Gehrels, N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Blandford, R. D.] Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94309 USA. [Cotter, G.] Univ Oxford, Dept Astrophys, Oxford OX1 3RH, England. RP Taylor, GB (reprint author), Univ New Mexico, Dept Phys & Astron, 800 Yale Blvd NE, Albuquerque, NM 87131 USA. RI Helmboldt, Joseph/C-8105-2012; Gehrels, Neil/D-2971-2012; Tremblay, Steven/C-1617-2013; Pearson, Timothy/N-2376-2015 OI Pearson, Timothy/0000-0001-5213-6231 NR 31 TC 36 Z9 36 U1 1 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 1355 EP 1364 DI 10.1086/523264 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600024 ER PT J AU Hickox, RC Jones, C Forman, WR Murray, SS Brodwin, M Brown, MJI Eisenhardt, PR Stern, D Kochanek, CS Eisenstein, D Cool, RJ Jannuzi, BT Dey, A Brand, K Gorjian, V Caldwell, N AF Hickox, R. C. Jones, C. Forman, W. R. Murray, S. S. Brodwin, M. Brown, M. J. I. Eisenhardt, P. R. Stern, D. Kochanek, C. S. Eisenstein, D. Cool, R. J. Jannuzi, B. T. Dey, A. Brand, K. Gorjian, V. Caldwell, N. TI A large population of mid-infrared-selected, obscured active galaxies in the Bootes field SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; infrared : galaxies; quasars : general; surveys; X-rays : galaxies ID DIGITAL SKY SURVEY; SPECTRAL ENERGY-DISTRIBUTIONS; SPITZER-SPACE-TELESCOPE; QUASAR LUMINOSITY FUNCTION; XMM-NEWTON OBSERVATIONS; IRAC SHALLOW SURVEY; RAY-SELECTED AGN; X-RAY; GALACTIC NUCLEI; DEEP FIELD AB We identify a population of 640 obscured and 839 unobscured AGNs at redshifts 0.7 < z <= 3 using multiwave-length observations of the 9 deg(2) NOAO Deep Wide-Field Survey (NDWFS) region in Bootes. We select AGNs on the basis of Spitzer IRAC colors obtained by the IRAC Shallow Survey. Redshifts are obtained from optical spectroscopy or photometric redshift estimators. We classify the IR-selected AGNs as IRAGN 1 (unobscured) and IRAGN 2 (obscured) using a simple criterion based on the observed optical to mid-IR color, with a selection boundary of R - [4.5] = 6.1, where R and [4.5] are the Vega magnitudes in the R and IRAC 4.5 mu m bands, respectively. We verify this selection using X-ray stacking analyses with data from the Chandra XBootes survey, as well as optical photometry from NDWFS and spectroscopy from MMT/AGES. We show that (1) these sources are indeed AGNs, and (2) the optical/IR color selection separates obscured sources (with average N-H similar to 3 x 10(22) cm(-2) obtained from X-ray hardness ratios, and optical colors and morphologies typical of galaxies) and unobscured sources (with no X-ray absorption, and quasar colors and morphologies), with a reliability of greater than or similar to 80%. The observed numbers of IRAGNs are comparable to predictions from previous X-ray, optical, and IR luminosity functions, for the given redshifts and IRAC flux limits. We observe a bimodal distribution in R - [4.5] color, suggesting that luminous IR-selected AGNs have either low or significant dust extinction, which may have implications for models of AGN obscuration. C1 [Hickox, R. C.; Jones, C.; Forman, W. R.; Murray, S. S.; Caldwell, N.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Brodwin, M.; Eisenhardt, P. R.; Stern, D.; Gorjian, V.] CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. [Brodwin, M.; Jannuzi, B. T.; Brand, K.] Natl Opt Astron Observ, Tucson, AZ 85726 USA. [Brown, M. J. I.] Monash Univ, Sch Phys, Clayton, Vic 3800, Australia. [Kochanek, C. S.] Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. [Eisenstein, D.] Steward Observ, Tucson, AZ 85721 USA. [Brand, K.] Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Hickox, RC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM rhickox@cfa.harvard.edu RI Brown, Michael/B-1181-2015; OI Brown, Michael/0000-0002-1207-9137; Forman, William/0000-0002-9478-1682 NR 99 TC 74 Z9 74 U1 0 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 1365 EP 1387 DI 10.1086/523082 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600025 ER PT J AU Cote, P Ferrarese, L Jordan, A Blakeslee, JP Chen, CW Infante, L Merritt, D Mei, S Peng, EW Tonry, JL West, AA West, MJ AF Cote, Patrick Ferrarese, Laura Jordan, Andres Blakeslee, John P. Chen, Chin-Wei Infante, Leopoldo Merritt, David Mei, Simona Peng, Eric W. Tonry, John L. West, Andrew A. West, Michael J. TI The ACS Fornax Cluster Survey. II. The central brightness profiles of early-type galaxies: A characteristic radius on nuclear scales and the transition from central luminosity deficit to excess SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (Virgo; Fornax); galaxies : elliptical and lenticular, cD; galaxies : nuclei; galaxies : structure ID HUBBLE-SPACE-TELESCOPE; SUPERMASSIVE BLACK-HOLES; DWARF ELLIPTIC GALAXIES; DATA REDUCTION PROCEDURES; VIRGO-CLUSTER; CENTRAL REGIONS; ADVANCED CAMERA; REDSHIFT SURVEY; PHOTOMETRY; CENTERS AB We analyze brightness profiles for 143 early-type galaxies in the Virgo and Fornax Clusters, observed with the Advanced Camera for Surveys on the Hubble Space Telescope. Sersic models are found to provide accurate representations of the global profiles with a notable exception: the observed profiles deviate systematically inside a characteristic "break'' radius of Rb approximate to 0.02 +0.025 -0.01 R-e, where R-e is the effective radius of the galaxy. The sense of the deviation is such that bright galaxies (M-B less than or similar to - 20) typically show central light deficits with respect to the inward extrapolation of the Sersic model, while the great majority of low-and intermediate-luminosity galaxies (-19.5 less than or similar to M-B less than or similar to - 15) show central light excesses; galaxies of intermediate luminosities (-20 less than or similar to M-B less than or similar to - 19.5) are generally well fitted by Sersic models over all radii. We show that the slope, gamma', of the central surface brightness profiles, when measured at fixed fractions of Re, varies smoothly as a function of galaxy luminosity in a manner that depends sensitively on the choice of measurement radius. We find no evidence for a core/power-law dichotomy, and show that a recent claim of strong bimodality in gamma' is likely an artifact of the biased galaxy selection function used in that study. To provide a more robust characterization of the inner regions of galaxies, we introduce a parameter Delta(0.02) = log (L-g/L-S)-where L-g and L-S are the integrated luminosities inside 0.02R(e) of the observed profile and of the inward extrapolation of the outer Sersic model-to describe the central luminosity deficit (Delta(0.02) < 0) or excess (Delta(0.02) > 0). We find that Delta(0.02) varies smoothly over the range of approximate to 720 in luminosity spanned by the sample galaxies, with again no evidence for a dichotomy. We argue that the central light excesses in M-B greater than or similar to - 19 galaxies may be the analogs of the dense central cores predicted by some numerical simulations to form via gas inflows. C1 [Cote, Patrick; Ferrarese, Laura; Chen, Chin-Wei; Peng, Eric W.] Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7, Canada. [Jordan, Andres] European So Observ, D-85748 Garching, Germany. [Blakeslee, John P.] Washington State Univ, Dept Phys & Astron, Pullman, WA 99164 USA. [Chen, Chin-Wei] Natl Cent Univ, Inst Astron, Chungli 32054, Taiwan. [Infante, Leopoldo] Pontificia Univ Catolica Chile, Dept Astron & Astrophys, Santiago, Chile. [Merritt, David] Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. [Mei, Simona] GEPI, Observ Paris, Meudon, France. [Tonry, John L.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. [West, Andrew A.] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. [West, Michael J.] Univ Hawaii, Dept Phys & Astron, Hilo, HI 96720 USA. [West, Michael J.] Gemini Observ, La Serena, Chile. RP Cote, P (reprint author), NASA, Washington, DC 20546 USA. RI West, Andrew/H-3717-2014; OI Jordan, Andres/0000-0002-5389-3944; Blakeslee, John/0000-0002-5213-3548 NR 57 TC 79 Z9 79 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 1456 EP 1465 DI 10.1086/522822 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600030 ER PT J AU Wise, JH Abel, T AF Wise, John H. Abel, Tom TI Suppression of H(2) cooling in the ultraviolet background SO ASTROPHYSICAL JOURNAL LA English DT Article DE early universe; Galaxy : formation; stars : formation ID PROBE WMAP OBSERVATIONS; 2ND-GENERATION STAR-FORMATION; 1ST COSMOLOGICAL OBJECTS; POPULATION-III STARS; X-RAY-CLUSTERS; RADIATIVE FEEDBACK; GALAXY FORMATION; PRIMORDIAL STAR; HIGH-REDSHIFT; HII-REGIONS AB The first luminous objects in the concordance cosmology form by molecular hydrogen cooling in dark matter dominated halos of masses similar to 10(6) M(circle dot). We use Eulerian adaptive mesh refinement simulations to demonstrate that in the presence of a large soft ultraviolet radiation background, molecular hydrogen is the dominant coolant. Even for very large radiation backgrounds, the halo masses that cool and collapse are up to 2 orders of magnitude smaller than the halos that cool via atomic hydrogen line cooling. The abundance of cooling halos and the cosmic mass fraction contained within them depends exponentially on this critical mass scale. Consequently, the majority of current models of cosmological reionization, chemical evolution, supermassive black hole formation, and galaxy formation underestimate the number of star-forming progenitors of a given system by orders of magnitude. At the highest redshifts, this disagreement is largest. We also show that even in the absence of residual electrons, collisional ionization in central shocks create a sufficient amount of electrons to form molecular hydrogen and cool the gas in halos of virial temperatures far below the atomic cooling limit. C1 [Wise, John H.; Abel, Tom] Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA. [Wise, John H.] NASA, Goddard Space Flight Ctr, Lab Observ Cosmol, Greenbelt, MD 20771 USA. RP Wise, JH (reprint author), Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. NR 78 TC 86 Z9 86 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 1559 EP 1567 DI 10.1086/522876 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600039 ER PT J AU Chincarini, G Moretti, A Romano, P Falcone, AD Morris, D Racusin, J Campana, S Covino, S Guidorzi, C Tagliaferri, G Burrows, DN Pagani, C Stroh, M Grupe, D Capalbi, M Cusumano, G Gehrels, N Giommi, P La Parola, V Mangano, V Mineo, T Nousek, JA O'Brien, PT Page, KL Perri, M Troja, E Willingale, R Zhang, B AF Chincarini, G. Moretti, A. Romano, P. Falcone, A. D. Morris, D. Racusin, J. Campana, S. Covino, S. Guidorzi, C. Tagliaferri, G. Burrows, D. N. Pagani, C. Stroh, M. Grupe, D. Capalbi, M. Cusumano, G. Gehrels, N. Giommi, P. La Parola, V. Mangano, V. Mineo, T. Nousek, J. A. O'Brien, P. T. Page, K. L. Perri, M. Troja, E. Willingale, R. Zhang, B. TI The first survey of X-ray flares from gamma-ray bursts observed by Swift: Temporal properties and morphology SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; X-rays : bursts ID AFTERGLOW EMISSION; BATSE OBSERVATIONS; REFRESHED SHOCKS; ENGINE ACTIVITY; LIGHT CURVES; LONG; TELESCOPE; BRIGHT; ORIGIN; VARIABILITY AB We present the first systematic investigation of the morphological and timing properties of flares in GRBs observed by Swift XRT. We consider a large sample drawn from all GRBs detected by Swift, INTEGRAL, and HETE-2 prior to 2006 January 31, which had an XRT follow-up and which showed significant flaring. Our sample of 33 GRBs includes long and short, at low and high redshift, and a total of 69 flares. The strongest flares occur in the early phases, with a clear anticorrelation between the flare peak intensity and the flare time of occurrence. Fitting each X-ray flare with a Gaussian model, we find that the mean ratio of the width and peak time is = 0.13 +/- 0.10, albeit with a large scatter. Late flares at times > 2000 s have long durations, Delta t > 300 s, and can be very energetic compared to the underlying continuum. We further investigated whether there is a clear link between the number of pulses detected in the prompt phase by BAT and the number of X-ray flares detected by XRT, finding no correlation. However, we find that the distribution of intensity ratios between successive BAT prompt pulses and that between successive XRT flares is the same, an indication of a common origin for gamma-ray pulses and X-ray flares. All evidence indicates that flares are indeed related to the workings of the central engine and, in the standard fireball scenario, originate from internal shocks rather than external shocks. While all flares can be explained by long-lasting engine activity, 29/69 flares may also be explained by refreshed shocks. However, 10 can only be explained by prolonged activity of the central engine. C1 [Chincarini, G.; Moretti, A.; Romano, P.; Campana, S.; Covino, S.; Guidorzi, C.; Tagliaferri, G.] INAF Osservatorio Astron Brera, I-23807 Merate, LC, Italy. [Chincarini, G.; Romano, P.; Guidorzi, C.] Univ Milan, I-20126 Milan, Italy. [Falcone, A. D.; Morris, D.; Racusin, J.; Burrows, D. N.; Pagani, C.; Stroh, M.; Grupe, D.; Nousek, J. A.] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. [Capalbi, M.; Giommi, P.; Perri, M.] ASI Sci Data Ctr, I-00044 Frascati, Italy. [Tagliaferri, G.; La Parola, V.; Mangano, V.; Mineo, T.; Troja, E.] INAF Ist Fis Spaziale & Fis Cosm, Sez Palermo, I-90146 Palermo, Italy. [Gehrels, N.] NASA Goddard Space Flight Ctr, Greenbelt, MD 20711 USA. [O'Brien, P. T.; Page, K. L.; Willingale, R.] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. [Zhang, B.] Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. RP Chincarini, G (reprint author), INAF Osservatorio Astron Brera, I-23807 Merate, LC, Italy. RI Racusin, Judith/D-2935-2012; Gehrels, Neil/D-2971-2012; OI Covino, Stefano/0000-0001-9078-5507; Tagliaferri, Gianpiero/0000-0003-0121-0723; Mineo, Teresa/0000-0002-4931-8445; giommi, paolo/0000-0002-2265-5003; Cusumano, Giancarlo/0000-0002-8151-1990; moretti, alberto/0000-0002-9770-0315; Perri, Matteo/0000-0003-3613-4409; La Parola, Valentina/0000-0002-8087-6488 NR 91 TC 143 Z9 144 U1 0 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 1903 EP 1920 DI 10.1086/521591 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600065 ER PT J AU Falcone, AD Morris, D Racusin, J Chincarini, G Moretti, A Romano, P Burrows, DN Pagani, C Stroh, M Grupe, D Campana, S Covino, S Tagliaferri, G Willingale, R Gehrels, N AF Falcone, A. D. Morris, D. Racusin, J. Chincarini, G. Moretti, A. Romano, P. Burrows, D. N. Pagani, C. Stroh, M. Grupe, D. Campana, S. Covino, S. Tagliaferri, G. Willingale, R. Gehrels, N. TI The first survey of X-ray flares from gamma-ray bursts observed by Swift: Spectral properties and energetics SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; X-rays : general ID ENGINE ACTIVITY; BATSE OBSERVATIONS; PROMPT EMISSION; LIGHT CURVES; AFTERGLOW; LONG; TELESCOPE; LUMINOSITY; BEPPOSAX; HARDNESS AB GRB observations with Swift produced the initially surprising result that many bursts have large, late-time X-ray flares. The flares were sometimes intense, had rapid rise and decay phases, and occurred late relative to the prompt phase. Many GRBs have had several flares, which were sometimes overlapping. The origin of the flares can be investigated by comparing the spectra during the flares to those of the afterglow and the initial prompt emission. In this work we have analyzed all significant X-ray flares from the first 110 GRBs observed by Swift. Significant X-ray flares (>3 sigma) were found in 33 of these GRBs, with 77 flares detected. A variety of spectral models have been fit to each flare. We find that the spectral fits sometimes favor a Band function model, which is more akin to the prompt emission than to that of the afterglow. While some flares are approximately as energetic as the prompt GRB emission, we find that the average fluence of the flares is approximately 10 times below the average prompt GRB fluence. We also find that the peak energy of the observed flares is typically in the soft X-ray band, as one might expect due to the X-ray selection of the sample. These results, when combined with those presented in the companion paper on temporal properties of flares, support the hypothesis that many X-ray flares are from late-time activity of the internal engine that spawned the initial GRB, not from an afterglow-related effect. C1 [Falcone, A. D.; Morris, D.; Racusin, J.; Burrows, D. N.; Pagani, C.; Stroh, M.; Grupe, D.] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. [Chincarini, G.; Moretti, A.; Romano, P.; Campana, S.; Covino, S.; Tagliaferri, G.] INAF Osservatorio Astron Brera, Merate, Italy. [Chincarini, G.; Romano, P.] Univ Milano Bicocca, Dipartimento Fis, Milan, Italy. [Willingale, R.] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. [Gehrels, N.] NASA Goddard Space Flight Ctr, Greenbelt, MD USA. RP Falcone, AD (reprint author), Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. EM afalcone@astro.psu.edu RI Racusin, Judith/D-2935-2012; Gehrels, Neil/D-2971-2012; OI moretti, alberto/0000-0002-9770-0315; Covino, Stefano/0000-0001-9078-5507; Tagliaferri, Gianpiero/0000-0003-0121-0723 NR 58 TC 113 Z9 114 U1 0 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 1921 EP 1938 DI 10.1086/523296 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600066 ER PT J AU Rajagopal, J Menut, JL Wallace, D Danchi, WC Chesneau, O Lopez, B Monnier, JD Ireland, M Tuthill, PG AF Rajagopal, Jayadev Menut, Jean-Luc Wallace, D. Danchi, W. C. Chesneau, O. Lopez, B. Monnier, J. D. Ireland, M. Tuthill, P. G. TI Mid-infrared interferometry of dust around massive evolved stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : individual (AG Car, NaSt 1, WR 95, WR 106); techniques : interferometric ID WOLF-RAYET STARS; LUMINOUS BLUE VARIABLES; LARGE-MAGELLANIC-CLOUD; RADIATIVE-TRANSFER; AG CARINAE; PINWHEEL NEBULA; SPECTROSCOPY; CATALOG; CAR; EVOLUTION AB We report long-baseline interferometric measurements of circumstellar dust around massive evolved stars with the MIDI instrument on the Very Large Telescope Interferometer and provide spectrally dispersed visibilities in the 8-13 mu m wavelength band. We also present diffraction-limited observations at 10.7 mu m on the Keck Telescope with baselines up to 8.7 m, which explore larger scale structure. We have resolved the dust shells around the late-type WC stars WR 106 and WR 95 and the enigmatic NaSt1 ( formerly WR 122), suspected to have recently evolved from a luminous blue variable (LBV) stage. For AG Car, the prototypical LBV in our sample, we marginally resolve structure close to the star, distinct from the well-studied detached nebula. The dust shells around the two WC stars show fairly constant size in the 8-13 mu m MIDI band, with Gaussian half-widths of similar to 25 to 40 mas, and the Keck observations reveal an additional extended structure around WR 106. The visibility profiles for NaSt 1 obtained from two MIDI baselines indicate a compact source embedded in an extended structure. The compact dust we detect around NaSt 1 and AG Car favors recent or ongoing dust formation. Using the measured visibilities, we build spherically symmetric radiative transfer models of the WC dust shells, which enable detailed comparison with existing SED-based models. Our results indicate that the inner radii of the shells are within a few tens of AU from the stars. In addition, our models favor grain size distributions with large (similar to 1 mu m) dust grains. This proximity of the inner dust to the hot central star emphasizes the difficulty faced by current theories in forming dust in the hostile environment around WR stars. Although we detect no direct evidence for binarity for these objects, dust production in a colliding-wind interface in a binary system is a feasible mechanism in WR systems under these conditions. C1 [Rajagopal, Jayadev] Univ Maryland, College Pk, MD 20742 USA. [Menut, Jean-Luc; Lopez, B.] Observ Cote Azur, Dept Gemini, UMR 6203, F-6203 Nice, France. [Wallace, D.; Danchi, W. C.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Monnier, J. D.] Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. [Chesneau, O.] Observ Cote Azur, Dept Gemini, Grasse, France. [Ireland, M.] CALTECH, Pasadena, CA 91125 USA. [Tuthill, P. G.] Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia. RP Rajagopal, J (reprint author), CTIO, Casilla 603, La Serena, Chile. EM jrajagopal@ctio.noao.edu OI Ireland, Michael/0000-0002-6194-043X NR 54 TC 8 Z9 8 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 2017 EP 2027 DI 10.1086/522515 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600073 ER PT J AU Wisniewski, JP Bjorkman, KS Magalhaes, AM Bjorkman, JE Meade, MR Pereyra, A AF Wisniewski, J. P. Bjorkman, K. S. Magalhaes, A. M. Bjorkman, J. E. Meade, M. R. Pereyra, Antonio TI The role of evolutionary age and metallicity in the formation of classical be circumstellar disks. II. Assessing the evolutionary nature of candidate disk systems SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; galaxies : clusters : individual (Bruck 60,NGC 330, NGC 346, NGC 371, NGC 456, NGC 458, LH 72, NGC 1818, NGC 1858, NGC 1948, NGC 2004, NGC 2100); Magellanic Clouds; stars : emission-line, Be; techniques : polarimetric; stars : individual (pi Aquarii, BD+61 154, MWC 349A) ID SMALL-MAGELLANIC-CLOUD; HERBIG AE/BE STARS; CLUSTER NGC 330; AE-BE STARS; WAVELENGTH DEPENDENCE; INTERSTELLAR POLARIZATION; LINEAR-POLARIZATION; SPECTROPOLARIMETRIC VARIABILITY; B SUPERGIANTS; YOUNG CLUSTERS AB We present the first detailed imaging polarization observations of six SMC and six LMC clusters, known to have large populations of B- type stars that exhibit excess H alpha emission from 2-CD photometric studies, to constrain the evolutionary status of these stars and hence better establish links between the onset of disk formation in classical Be stars and cluster age and/or metallicity. We parameterize and remove the interstellar polarization (ISP) associated with each line of sight, thereby isolating the presence of any intrinsic polarization. We use the wavelength dependence of this intrinsic polarization to discriminate pure gas disk systems, i.e., classical Be stars, from composite gas-plus-dust disk systems, i.e., Herbig Ae/Be or B[e] stars. Our intrinsic polarization results, along with available near-IR color information, support the suggestion of Wisniewski et al. that classical Be stars are present in clusters of age 5-8 Myr and contradict assertions that the Be phenomenon only develops in the second half of a B star's main-sequence lifetime, i.e., no earlier than 10 Myr. The prevalence of polarimetric Balmer jump signatures decreases with metallicity; we speculate that either it is more difficult to form large disk systems in low-metallicity environments or that average disk temperatures are higher in low-metallicity environments. The polarimetric signatures of similar to 25% of our sample appear unlikely to arise from true classical Be star disk systems, suggesting one should proceed with caution when attempting to determine the role of evolutionary age and/or metallicity in the Be phenomenon purely via 2-CD results. C1 [Wisniewski, J. P.] NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. [Bjorkman, K. S.; Bjorkman, J. E.] Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA. [Magalhaes, A. M.; Pereyra, Antonio] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atomosfer, BR-01060970 Sao Paulo, Brazil. [Meade, M. R.] Univ Wisconsin, Space Astron Lab, Madison, WI 53706 USA. RP Wisniewski, JP (reprint author), NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Code 667, Greenbelt, MD 20771 USA. EM John.P.Wisniewski@nasa.gov; Karen.Bjorkman@.utoledo.edu; mario@astroiag.usp.br; Jon.Bjorkman@utoledo.edu; meade@sal.wisc.edu; antonio@astro.iag.usp.br RI Magalhaes, Antonio Mario/K-9532-2013; Pereyra, Antonio/E-4547-2013 NR 77 TC 18 Z9 18 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2007 VL 671 IS 2 BP 2040 EP 2058 DI 10.1086/522293 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AN UT WOS:000253331600075 ER PT J AU Brodwin, M Gonzalez, AH Moustakas, LA Eisenhardt, PR Stanford, SA Stern, D Brown, MJI AF Brodwin, M. Gonzalez, A. H. Moustakas, L. A. Eisenhardt, P. R. Stanford, S. A. Stern, D. Brown, M. J. I. TI Galaxy cluster correlation function to z similar to 1.5 in the IRAC shallow cluster survey SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE cosmology : observations; galaxies : clusters : general; large-scale structure of universe ID SPATIAL CORRELATION-FUNCTION; EXTREMELY RED OBJECTS; LAMBDA-CDM COSMOLOGY; REDSHIFT SURVEY; X-RAY; POWER SPECTRUM; DARK ENERGY; EVOLUTION; QUASARS; DISTANT AB We present the galaxy cluster autocorrelation function of 277 galaxy cluster candidates with in 0.25 <= z <= 1.5 a 7 deg(2) area of the IRAC Shallow Cluster Survey. We find strong clustering throughout our galaxy cluster sample, as expected for these massive structures. Specifically, at < z >=0.5 we find a correlation length of r(0)=17.40(-3.10)(+3.98) h(-1)Mpc, in excellent agreement with the Las Campanas Distant Cluster Survey, the only other nonlocal measurement. At higher redshift,, we find that strong clustering persists, with a correlation AzS p 1 length of r(0)=19.14(-4.56)(+5.65) h(-1) Mpc. A comparison with high-resolution cosmological simulations indicates these are clusters with halo masses of similar to 10(14) M-circle dot, a result supported by estimates of dynamical mass for a subset of the sample. In a stable clustering picture, these clusters will evolve into massive (10(15) M-circle dot) clusters by the present day. C1 [Brodwin, M.; Moustakas, L. A.; Eisenhardt, P. R.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. [Brodwin, M.] Natl Opt Astron Observ, Tucson, AZ 85726 USA. [Gonzalez, A. H.] Univ Florida, Dept Astron, Gainesville, FL 32611 USA. [Stanford, S. A.] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. [Stanford, S. A.] Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. [Brown, M. J. I.] Monash Univ, Sch Phys, Clayton, Vic 3168, Australia. RP Brodwin, M (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RI Brown, Michael/B-1181-2015; OI Brown, Michael/0000-0002-1207-9137; Moustakas, Leonidas/0000-0003-3030-2360 NR 40 TC 28 Z9 28 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA J9 ASTROPHYS J LETT JI Astrophys. J. Lett. PD DEC 20 PY 2007 VL 671 IS 2 BP L93 EP L96 DI 10.1086/525558 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 291XW UT WOS:000255231700002 ER PT J AU Evans, A Woodward, CE Helton, LA van Loon, JT Barry, RK Bode, MF Davis, RJ Drake, JJ Eyres, SPS Geballe, TR Gehrz, RD Kerr, T Krautter, J Lynch, DK Ness, JU O'Brien, TJ Osborne, JP Page, KL Rudy, RJ Russell, RW Schwarz, G Starrfield, S Tyne, VH AF Evans, A. Woodward, C. E. Helton, L. A. van Loon, J. Th. Barry, R. K. Bode, M. F. Davis, R. J. Drake, J. J. Eyres, S. P. S. Geballe, T. R. Gehrz, R. D. Kerr, T. Krautter, J. Lynch, D. K. Ness, J. -U. O'Brien, T. J. Osborne, J. P. Page, K. L. Rudy, R. J. Russell, R. W. Schwarz, G. Starrfield, S. Tyne, V. H. TI Silicate dust in the environment of RS Ophiuchi following the 2006 eruption SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE binaries : close; binaries : symbiotic; infrared : stars; novae, cataclysmic variables; stars : individual (RS Oph) ID SPITZER-SPACE-TELESCOPE; INFRARED OBSERVATIONS; SYMBIOTIC STARS; SHOCK-WAVE; OUTBURST; EMISSION; EVOLUTION; SPECTRA; NOVAE; PHASE AB We present further Spitzer Space Telescope observations of the recurrent nova RS Ophiuchi, obtained over the period 208 - 430 days after the 2006 eruption. The later Spitzer IRS data show that the line emission and free-free continuum emission reported earlier is declining, revealing incontrovertible evidence for the presence of silicate emission features at 9.7 and 18 mm. We conclude that the silicate dust survives the hard radiation impulse and shock blast wave from the eruption. The existence of the extant dust may have significant implications for understanding the propagation of shocks through the red giant wind and likely wind geometry. C1 [Evans, A.; van Loon, J. Th.; Tyne, V. H.] Univ Keele, Lennard Jones Lab, Astrophys Grp, Keele ST5 5BG, Staffs, England. [Woodward, C. E.; Helton, L. A.; Gehrz, R. D.] Univ Minnesota, Sch Phys & Astron, Dept Astron, Minneapolis, MN 55455 USA. [Barry, R. K.] NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. [Bode, M. F.] Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England. [Davis, R. J.; O'Brien, T. J.] Univ Manchester, Jodrell Bank, Ctr Astrophys, Manchester M13 9PL, Lancs, England. [Drake, J. J.] Harvard Smithsonian Ctr Astrophys, CFA, Cambridge, MA 02138 USA. [Eyres, S. P. S.] Univ Cent Lancashire, Ctr Astrophys, Preston PR1 2HE, Lancs, England. [Geballe, T. R.] Gemini Observ, Hilo, HI 96720 USA. [Kerr, T.] Joint Astron Ctr, Hilo, HI 96720 USA. [Krautter, J.] Landessternwarte Konigstuhl, D-69117 Heidelberg, Germany. [Lynch, D. K.; Rudy, R. J.; Russell, R. W.] Aerosp Corp, Los Angeles, CA 90009 USA. [Ness, J. -U.; Starrfield, S.] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. [Osborne, J. P.; Page, K. L.] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. [Schwarz, G.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Evans, A (reprint author), Univ Keele, Lennard Jones Lab, Astrophys Grp, Keele ST5 5BG, Staffs, England. EM ae@astro.keele.ac.uk; chelsea@astro.umn.edu; ahelton@astro.umn.edu; jacco@astro.keele.ac.uk; richard.k.barry@nasa.gov; mfb@astro.livjm.ac.uk; rjd@jb.man.ac.uk; gehrz@astro.umn.edu; vht@astro.keele.ac.uk NR 38 TC 26 Z9 26 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 2041-8205 EI 2041-8213 J9 ASTROPHYS J LETT JI Astrophys. J. Lett. PD DEC 20 PY 2007 VL 671 IS 2 BP L157 EP L160 DI 10.1086/524944 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 291XW UT WOS:000255231700018 ER PT J AU Hines, DC Schneider, G Hollenbach, D Mamajek, EE Hillenbrand, LA Metchev, SA Meyer, MR Carpenter, JM Moro-Martin, A Silverstone, MD Kim, JS Henning, T Bouwman, J Wolf, S AF Hines, Dean C. Schneider, Glenn Hollenbach, David Mamajek, Eric E. Hillenbrand, Lynne A. Metchev, Stanimir A. Meyer, Michael R. Carpenter, John M. Moro-Martin, Amaya Silverstone, Murray D. Kim, Jinyoung Serena Henning, Thomas Bouwman, Jeroen Wolf, Sebastian TI The moth: an unusual circumstellar structure associated with HD 61005 SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE circumstellar matter; infrared : stars; planetary systems : protoplanetary disks; stars : individual (HD 61005) ID SOLAR-TYPE STARS; SUN-LIKE STARS; PLANETARY SYSTEMS FEPS; DEBRIS DISKS; INTERSTELLAR-MEDIUM; YOUNG STARS; EVOLUTION; DUST; DISCOVERY; SPITZER AB We present the discovery of an unusual spatially resolved circumstellar structure associated with the approximate to 90 Myr, nearby, G dwarf star HD 61005. Observations from the FEPS Spitzer Legacy Science survey reveal thermal emission in excess of expected stellar photospheric levels. Follow-up 0.1 '' resolution HST NICMOS coronagraphic images reveal scattered starlight <= 7 '' (similar to 240 AU) from the occulted star (1.1 mu m flux density = 18 +/- 3.3 mJy; and 0.77%+/- 0.16% starlight). The extremely high near-IR scattering fraction and IR excess luminosity f=L-IR/L-* approximate to 2x10(-3) suggests scattering particle sizes of order a <= 1.1 mu m/2 pi similar to 0.2 mu m comparable to the blowout size (a approximate to 0.3 mu m) due to radiation a pressure from the star. Dust-scattered starlight is traced inward to an instrumental limit of similar to 10 AU. The structure exhibits a strong asymmetry about its morphological major axis but is mirror-symmetric about its minor axis. C1 [Hines, Dean C.] Space Sci Inst, Boulder, CO USA. [Schneider, Glenn; Meyer, Michael R.; Kim, Jinyoung Serena] Univ Arizona, Steward Observ, Tucson, AZ USA. [Hollenbach, David] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Mamajek, Eric E.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Hillenbrand, Lynne A.; Carpenter, John M.] CALTECH, Dept Astron, Pasadena, CA 91125 USA. [Metchev, Stanimir A.] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA USA. [Moro-Martin, Amaya] Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. [Silverstone, Murray D.] Eureka Sci, Cary, NC USA. [Henning, Thomas; Bouwman, Jeroen; Wolf, Sebastian] Max Planck Inst Astron, D-69117 Heidelberg, Germany. RP Hines, DC (reprint author), Space Sci Inst, Boulder, CO USA. NR 40 TC 43 Z9 43 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 2041-8205 J9 ASTROPHYS J LETT JI Astrophys. J. Lett. PD DEC 20 PY 2007 VL 671 IS 2 BP L165 EP L168 DI 10.1086/525016 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 291XW UT WOS:000255231700020 ER PT J AU Fridlind, AM Ackerman, AS McFarquhar, G Zhang, G Poellot, MR DeMott, PJ Prenni, AJ Heymsfield, AJ AF Fridlind, A. M. Ackerman, A. S. McFarquhar, G. Zhang, G. Poellot, M. R. DeMott, P. J. Prenni, A. J. Heymsfield, A. J. TI Ice properties of single-layer stratocumulus during the Mixed-Phase Arctic Cloud Experiment: 2. Model results SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID LARGE-EDDY SIMULATIONS; AEROSOL-PARTICLES; FORMING NUCLEI; BOUNDARY-LAYER; CONTACT NUCLEATION; CUMULUS CLOUDS; WATER DROPLETS; BEAUFORT SEA; WAVE-CLOUDS; MICROPHYSICAL PROPERTIES AB Measurements from the US Department of Energy Atmospheric Radiation Measurement Program's 2004 Mixed-Phase Arctic Cloud Experiment (M-PACE) provide a unique opportunity to study poorly understood ice formation processes in mixed-phase stratocumulus. Using meteorological, aerosol, and ice nucleus measurements to initialize large-eddy simulations with size-resolved microphysics, we compare predicted liquid and ice mass, number, and size distribution with observations from a typical flight. We find that ambient ice nuclei appear insufficient by a few orders of magnitude to explain observed ice, consistent with past literature. We also find that two processes previously hypothesized to explain the discrepancy, shatter of freezing drops and fragmentation during ice-ice collisions, were not significant sources of ice based on parameterizations from existing studies. After surveying other mechanisms that have been hypothesized to explain ice formation in mixed-phase clouds generally, we find two that may be strong enough: ( 1) formation of ice nuclei from drop evaporation residuals, a process suggested by sparse and limited measurements to date, and ( 2) drop freezing during evaporation, a process suggested only by inference at this time. The first mechanism can better explain the persistence of mixed-phase conditions in simulations of less vigorous stratus observed during the Beaufort Arctic Storms Experiment ( BASE). We consider conditions under which emission of nuclei from the ocean surface or activation through cloud-phase chemistry could provide alternative explanations for M-PACE observations. Additional process-oriented measurements are suggested to distinguish among ice formation mechanisms in future field studies. C1 [Fridlind, A. M.; Ackerman, A. S.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [McFarquhar, G.; Zhang, G.] Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. [Poellot, M. R.] Univ N Dakota, Dept Atmospher Sci, Grand Forks, ND 58201 USA. [DeMott, P. J.; Prenni, A. J.] Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. [Heymsfield, A. J.] Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Fridlind, AM (reprint author), NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RI Prenni, Anthony/A-6820-2011; DeMott, Paul/C-4389-2011; Heymsfield, Andrew/E-7340-2011; Ackerman, Andrew/D-4433-2012; Fridlind, Ann/E-1495-2012; OI DeMott, Paul/0000-0002-3719-1889; Ackerman, Andrew/0000-0003-0254-6253; McFarquhar, Greg/0000-0003-0950-0135 NR 102 TC 88 Z9 89 U1 4 U2 22 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 2007 VL 112 IS D24 AR D24202 DI 10.1029/2007JD008646 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 244PS UT WOS:000251878400005 ER PT J AU Kovalenko, LJ Livesey, NL Salawitch, RJ Camy-Peyret, C Chipperfield, MP Cofield, RE Dorf, M Drouin, BJ Froidevaux, L Fuller, RA Goutail, F Jarnot, RF Jucks, K Knosp, BW Lambert, A MacKenzie, IA Pfeilsticker, K Pommereau, JP Read, WG Santee, ML Schwartz, MJ Snyder, WV Stachnik, R Stek, PC Wagner, PA Waters, JW AF Kovalenko, L. J. Livesey, N. L. Salawitch, R. J. Camy-Peyret, C. Chipperfield, M. P. Cofield, R. E. Dorf, M. Drouin, B. J. Froidevaux, L. Fuller, R. A. Goutail, F. Jarnot, R. F. Jucks, K. Knosp, B. W. Lambert, A. MacKenzie, I. A. Pfeilsticker, K. Pommereau, J. -P. Read, W. G. Santee, M. L. Schwartz, M. J. Snyder, W. V. Stachnik, R. Stek, P. C. Wagner, P. A. Waters, J. W. TI Validation of Aura Microwave Limb Sounder BrO observations in the stratosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID BROMINE BUDGET; OZONE; RETRIEVAL; MODEL; MLS AB Validation of stratospheric BrO vertical profiles obtained by the Microwave Limb Sounder (MLS) on the Aura satellite is discussed. MLS BrO measurements are compared with expectations of its latitudinal and seasonal dependence, as well as with more localized balloon-borne measurements of BrO. We describe the expected precision and systematic errors of the version 2.2 retrieval and show that scientific studies using MLS BrO vertical profiles require extensive averaging to increase the signal-to-noise ratio to useful values. A monthly zonal mean over a 10 degrees latitude bin ( about 3,000 individual profiles) results in a precision of approximately +/- 4 ppt (similar to 25% of a typical daytime signal). Moreover, it is necessary to take day/night differences to remove large biases. The pressure range over which the data are considered useful is 10 to 3.2 hPa. Over this range, the estimated accuracy in the day/night difference is about +/- 20%. The vertical resolution is 5.5 km for 10 to 3.2 hPa. Day/night differences are a good measure of daytime BrO from 10 to 4.6 hPa; for 3.2 hPa the nonnegligible nighttime BrO needs to be accounted for. We infer total inorganic bromine (Br-y) to be 22.1 +/- 5.5 ppt on the basis of analysis of MLS measurements of BrO, which implies a contribution of 6.5 +/- 5.5 ppt to stratospheric bromine from sources other than long-lived CH3Br and halons. C1 [Kovalenko, L. J.; Livesey, N. L.; Salawitch, R. J.; Cofield, R. E.; Drouin, B. J.; Froidevaux, L.; Fuller, R. A.; Jarnot, R. F.; Knosp, B. W.; Lambert, A.; Read, W. G.; Santee, M. L.; Schwartz, M. J.; Snyder, W. V.; Stachnik, R.; Stek, P. C.; Wagner, P. A.; Waters, J. W.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. [Salawitch, R. J.] Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD 20742 USA. [Camy-Peyret, C.] Univ Paris 06, Lab Phys Mol Atmosphere & Astrophys, Paris, France. [Chipperfield, M. P.] Univ Leeds, Sch Earth Environm, Inst Atmospher Sci, Leeds, W Yorkshire, England. [Dorf, M.; Pfeilsticker, K.] Heidelberg Univ, Inst Environm Phys, Heidelberg, Germany. [Goutail, F.; Pommereau, J. -P.] CNRS, Serv Aeron, F-91371 Verrieres Le Buisson, France. [Jucks, K.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [MacKenzie, I. A.] Univ Edinburgh, Sch Geosci, Edinburgh, Midlothian, Scotland. RP Kovalenko, LJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. RI Salawitch, Ross/B-4605-2009; mackenzie, ian/E-9320-2013; Chipperfield, Martyn/H-6359-2013; Schwartz, Michael/F-5172-2016 OI Salawitch, Ross/0000-0001-8597-5832; Chipperfield, Martyn/0000-0002-6803-4149; Schwartz, Michael/0000-0001-6169-5094 NR 33 TC 11 Z9 11 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 2007 VL 112 IS D24 AR D24S41 DI 10.1029/2007JD008817 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 244PS UT WOS:000251878400007 ER PT J AU Luo, M Rinsland, C Fisher, B Sachse, G Diskin, G Logan, J Worden, H Kulawik, S Osterman, G Eldering, A Herman, R Shephard, M AF Luo, M. Rinsland, C. Fisher, B. Sachse, G. Diskin, G. Logan, J. Worden, H. Kulawik, S. Osterman, G. Eldering, A. Herman, R. Shephard, M. TI TES carbon monoxide validation with DACOM aircraft measurements during INTEX-B 2006 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID POLLUTION; PERSPECTIVE; SATELLITE AB Validation of Tropospheric Emission Spectrometer (TES) tropospheric CO profiles with in situ CO measurements from the Differential Absorption CO Measurement (DACOM) instrument during the Intercontinental Chemical Transport Experiment (INTEX)-B campaigns in March to May 2006 are presented. For each identified DACOM CO profile, one to three TES CO profiles are selected closest in location to the small area that the DACOM profile covers. The time differences between the comparison profiles are within 2 hours. The DACOM CO vertical profiles are adjusted by applying nearest coincident TES averaging kernels and the a priori profiles. This step accounts for the effect of the vertical resolution of the TES CO retrievals and removes the influence of the a priori assumptions in the comparisons. Comparison statistics for data taken near Houston in March 2006 show good agreement between TES and the adjusted DACOM CO profiles in the lower and middle troposphere with a correlation coefficient of 0.87. On average, the TES CO volume mixing ratio profile is 0-10% lower than the adjusted DACOM CO profile from the lower to middle troposphere. This is within the 10-20% standard deviations of the TES or DACOM CO profiles taken in the Houston area. The comparisons of TES and DACOM CO profiles near Hawaii and Anchorage in April to May 2006 are not as good. In these regions the aircraft DACOM CO profiles are characterized by plumes or enhanced CO layers, consistent with known features in the tracer fields due to transpacific transport of polluted air parcels originating from East Asia. Although TES observations over the Pacific region also show localized regions of enhanced CO, the coincidence criteria for obtaining good comparisons with aircraft measurements are challenging. The meaning of validation comparisons in profile portions where TES retrievals have little sensitivity is addressed. Examinations of characteristic parameters in TES retrievals are important in data applications. C1 [Luo, M.; Fisher, B.; Diskin, G.; Worden, H.; Kulawik, S.; Osterman, G.; Eldering, A.; Herman, R.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. [Rinsland, C.; Sachse, G.; Diskin, G.] NASA, Langley Res Ctr, Hampton, VA 23665 USA. [Sachse, G.] Natl Inst Aerosp, Hampton, VA USA. [Logan, J.] Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. [Worden, H.] Natl Ctr Atmospher Res, Boulder, CO 80307 USA. [Shephard, M.] Atmospher & Environm Res Inc, Lexington, MA USA. RP Luo, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 19 TC 57 Z9 57 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 2007 VL 112 IS D24 AR D24S48 DI 10.1029/2007JD008803 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 244PS UT WOS:000251878400006 ER PT J AU McFarquhar, GM Zhang, G Poellot, MR Kok, GL Mccoy, R Tooman, T Fridlind, A Heymsfield, AJ AF McFarquhar, Greg M. Zhang, Gong Poellot, Michael R. Kok, Gregory L. McCoy, Robert Tooman, Tim Fridlind, Ann Heymsfield, Andrew J. TI Ice properties of single-layer stratocumulus during the Mixed-Phase Arctic Cloud Experiment: 1. Observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MOMENT MICROPHYSICS PARAMETERIZATION; GENERAL-CIRCULATION MODEL; WATER-CONTENT; CLIMATE MODELS; ANNUAL CYCLE; PART I; RESOLVING SIMULATIONS; RADIATIVE PROPERTIES; STRATIFORM CLOUDS; LIQUID FRACTION AB During the Department of Energy's Atmospheric Radiation Measurement Program's Mixed-Phase Arctic Cloud Experiment (M-PACE) in fall 2004, the University of North Dakota Citation measured 53 profiles within single-layer stratus clouds by executing spiral ascents and descents over Barrow and Oliktok Point, Alaska, and by flying ramped ascents and descents between. Cloud phase was identified from an algorithm that uses voltage change from the Rosemount ice detector, the size distribution (SD) shape measured by the Forward Scattering Spectrometer Probe (FSSP), and manual identification of particles imaged by the Cloud Particle Imager, the two-dimensional cloud probe (2DC) and the high-volume precipitation sampler (HVPS). Size and mass distribution functions were derived using data from the FSSP, one-dimensional cloud probe, 2DC and HVPS in conjunction with total water content (TWC) measured by the Counterflow Virtual Impactor. With clouds defined as locations where TWC > 0.001 g m(-3), there were a total of 513 30-s averaged SDs in single-layer clouds, of which 71% were in mixed-phase parcels, 23% in ice-phase and 6% in liquid-phase. The mixed-phase parcels were dominated by contributions from liquid drops, with the liquid mass fraction f(1) having averages and standard deviations of 0.89 +/- 0.18 with 75% of cases having f(1) > 0.9. For these single- layer clouds, f(1) increased with normalized cloud altitude z(n), defined as linearly increasing from 0 at cloud base to 1 at cloud top with fl averaging 0.96 +/- 0.13 near z(n) = 1 and 0.70 +/- 0.30 near z(n) = 0. The effective radius of water droplets r(ew) increased with z(n), from an average of 6.9 +/- 1.8 mu m near z(n) = 0 to 11.4 +/- 2.4 mu m near z(n) = 1, whereas the effective radius of ice crystals rei (25.2 +/- 3.9 mu m) was nearly independent of z(n). The averaged cloud droplet number concentration and concentrations of ice crystals with maximum dimensions greater than 53 mu m were 43.6 +/- 30.5 x 10(3) L-1 and 2.8 +/- 6.9 L-1, respectively, and nearly independent of z(n). In contrast to past measurements in mixed-phase clouds combined from many geographical locations where fl increased with temperature, f(1) decreased from -12 degrees to -3 degrees C as clouds typically consisted of a liquid topped layer with precipitating ice below. C1 [McFarquhar, Greg M.; Zhang, Gong] Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. [Poellot, Michael R.] Univ N Dakota, Dept Atmospher Sci, Grand Forks, ND 58201 USA. [Kok, Gregory L.] Droplet Measurement Technol, Boulder, CO USA. [McCoy, Robert; Tooman, Tim] Sandia Natl Labs, Livermore, CA USA. [Fridlind, Ann] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Heymsfield, Andrew J.] Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP McFarquhar, GM (reprint author), Univ Illinois, Dept Atmospher Sci, 105 S Gregory Ave, Urbana, IL 61801 USA. RI Heymsfield, Andrew/E-7340-2011; Fridlind, Ann/E-1495-2012; OI McFarquhar, Greg/0000-0003-0950-0135 NR 81 TC 100 Z9 103 U1 2 U2 22 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 2007 VL 112 IS D24 AR D24201 DI 10.1029/2007JD008633 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 244PS UT WOS:000251878400004 ER PT J AU Brandon, A AF Brandon, Alan TI Planetary science - A younger Moon SO NATURE LA English DT Editorial Material ID HF-W CHRONOMETRY; IMPACT; CRUST; EARTH; AGE C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Brandon, A (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 Nasa Pkwy, Houston, TX 77058 USA. EM alan.d.brandon@nasa.gov NR 11 TC 4 Z9 5 U1 1 U2 3 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD DEC 20 PY 2007 VL 450 IS 7173 BP 1169 EP 1170 DI 10.1038/4501169a PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 243HA UT WOS:000251786200030 PM 18097390 ER PT J AU Morabito, DD AF Morabito, David D. TI Detection of tropospheric propagation effects from deep space links of the Cassini spacecraft SO RADIO SCIENCE LA English DT Article ID AMPLITUDE SCINTILLATION; SATELLITE LINK; PREDICTION; MODEL; PATHS; GHZ AB The bandwidth allocations for frequencies that lie below 10 GHz are limited, and thus they cannot accommodate high rate communications requirements for future deep space missions. The transition to higher-frequency bands where there are higher bandwidth allocations is being considered for such missions. As communications frequencies increase, the degradation effects due to weather also increase. The statistics of such effects have been documented in a variety of experimental programs using geostationary satellites. Deep-space missions operate at much weaker received signal levels than near-Earth missions because of very large interplanetary distances. These weaker signal levels result in lower operating margins, and thus it becomes important to characterize propagation effects at these higher microwave frequencies. The Ka band frequency allocation (27-40 GHz) offers increased advantages over the X band allocation (8-12 GHz) for telecommunications. Such advantages include increased gain (using directional antennas) and increased bandwidth. Knowledge of weather degradation effects is essential for developing optimum telemetry return strategies at Ka band. This article will report on atmospheric induced effects that have been observed on a deep-space Ka band carrier signal (32 GHz) emitted by the Cassini spacecraft between December 2002 and January 2003. The results of such work will be beneficial in the planning of operations on future spacecraft with Ka band telemetry links. C1 [Morabito, David D.] CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Morabito, DD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA USA. NR 24 TC 0 Z9 0 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD DEC 20 PY 2007 VL 42 IS 6 AR RS6007 DI 10.1029/2007RS003642 PG 14 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA 244RW UT WOS:000251884000001 ER PT J AU Schoeberl, MR Ziemke, JR Bojkov, B Livesey, N Duncan, B Strahan, S Froidevaux, L Kulawik, S Bhartia, PK Chandra, S Levelt, PF Witte, JC Thompson, AM Cuevas, E Redondas, A Tarasick, DW Davies, J Bodeker, G Hansen, G Johnson, BJ Oltmans, SJ Vomel, H Allaart, M Kelder, H Newchurch, M Godin-Beekmann, S Ancellet, G Claude, H Andersen, SB Kyro, E Parrondos, M Yela, M Zablocki, G Moore, D Dier, H von der Gathen, P Viatte, P Stubi, R Calpini, B Skrivankova, P Dorokhov, V de Backer, H Schmidlin, FJ Coetzee, G Fujiwara, M Thouret, V Posny, F Morris, G Merrill, J Leong, CP Koenig-Langlo, G Joseph, E AF Schoeberl, M. R. Ziemke, J. R. Bojkov, B. Livesey, N. Duncan, B. Strahan, S. Froidevaux, L. Kulawik, S. Bhartia, P. K. Chandra, S. Levelt, P. F. Witte, J. C. Thompson, A. M. Cuevas, E. Redondas, A. Tarasick, D. W. Davies, J. Bodeker, G. Hansen, G. Johnson, B. J. Oltmans, S. J. Voemel, H. Allaart, M. Kelder, H. Newchurch, M. Godin-Beekmann, S. Ancellet, G. Claude, H. Andersen, S. B. Kyroe, E. Parrondos, M. Yela, M. Zablocki, G. Moore, D. Dier, H. von der Gathen, P. Viatte, P. Stuebi, R. Calpini, B. Skrivankova, P. Dorokhov, V. de Backer, H. Schmidlin, F. J. Coetzee, G. Fujiwara, M. Thouret, V. Posny, F. Morris, G. Merrill, J. Leong, C. P. Koenig-Langlo, G. Joseph, E. TI A trajectory-based estimate of the tropospheric ozone column using the residual method SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPICAL ATLANTIC; AURA MISSION; GLOBAL-MODEL; TOMS; SATELLITE; CHEMISTRY; TRACE AB We estimate the tropospheric column ozone using a forward trajectory model to increase the horizontal resolution of the Aura Microwave Limb Sounder (MLS) derived stratospheric column ozone. Subtracting the MLS stratospheric column from Ozone Monitoring Instrument total column measurements gives the trajectory enhanced tropospheric ozone residual (TTOR). Because of different tropopause definitions, we validate the basic residual technique by computing the 200-hPa-to-surface column and comparing it to the same product from ozonesondes and Tropospheric Emission Spectrometer measurements. Comparisons show good agreement in the tropics and reasonable agreement at middle latitudes, but there is a persistent low bias in the TTOR that may be due to a slight high bias in MLS stratospheric column. With the improved stratospheric column resolution, we note a strong correlation of extratropical tropospheric ozone column anomalies with probable troposphere-stratosphere exchange events or folds. The folds can be identified by their colocation with strong horizontal tropopause gradients. TTOR anomalies due to folds may be mistaken for pollution events since folds often occur in the Atlantic and Pacific pollution corridors. We also compare the 200-hPa-to-surface column with Global Modeling Initiative chemical model estimates of the same quantity. While the tropical comparisons are good, we note that chemical model variations in 200hPa-to-surface column at middle latitudes are much smaller than seen in the TTOR. C1 [Schoeberl, M. R.; Bojkov, B.; Bhartia, P. K.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Ziemke, J. R.; Bojkov, B.; Duncan, B.; Strahan, S.; Chandra, S.] Univ Maryland, Goddard Earth Sci & Technol, Baltimore, MD 21201 USA. [Livesey, N.; Froidevaux, L.; Kulawik, S.] NASA, Jet Propuls Lab, Pasadena, CA USA. [Levelt, P. F.; Allaart, M.] Royal Netherlands Meteorol Inst, NL-3730 AE De Bilt, Netherlands. [Witte, J. C.] Sci Syst & Applicat Inc, Lanham, MD USA. [Thompson, A. M.] Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. [Cuevas, E.; Redondas, A.] Izana Observ, Natl Inst Meteorol, Tenerife, Spain. [Tarasick, D. W.; Davies, J.] Environm Canada, Downsview, ON, Canada. [Bodeker, G.] Natl Inst Water & Atmospher Res, Lauder, New Zealand. [Hansen, G.] Norwegian Inst Air Res, Tromso, Norway. [Johnson, B. J.; Oltmans, S. J.] NOAA, Earth Syst Res Lab, Global Monitoring Div, Boulder, CO USA. [Voemel, H.] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. [Newchurch, M.] Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35899 USA. [Godin-Beekmann, S.; Ancellet, G.] Univ Paris 06, Ctr Natl Rech Sci, Serv Aeron, Paris, France. [Andersen, S. B.] Danish Meteorol Inst, Copenhagen, Denmark. [Parrondos, M.; Yela, M.] Finnish Meteorol Inst, Arct Res Ctr, Sodankyla, Finland. [Parrondos, M.; Yela, M.] Spanish Space Agcy, Lab Atmosfera, Madrid, Spain. [Zablocki, G.] Ctr Aerol, Natl Inst Meteorol & Hydrol, Legionowo, Poland. [Moore, D.] Met Off, Exeter, Devon, England. [Dier, H.] Meteorol Observ, German Weather Serv, Lindenberg, Germany. [Viatte, P.] Alfred Wegener Inst Polar & Marine Res, Potsdam, Germany. [Viatte, P.; Stuebi, R.; Calpini, B.] Aerol Stn Payeme, Payeme, Switzerland. [Skrivankova, P.] Czech Hydrometeorol Inst, Prague, Czech Republic. [Dorokhov, V.] Cent Aerol Observ, Moscow, Russia. [de Backer, H.] Royal Meteorol Inst Belgium, Uccle, Belgium. [Schmidlin, F. J.] NASA, Goddard Space Flight Ctr, Wallops Isl, VA 23337 USA. [Coetzee, G.] S African Weather Serv, Dept Environm Affairs & Tourism, Pretoria, South Africa. [Fujiwara, M.] Hokkaido Univ, Grad Sch Environm Earth Sci, Sapporo, Hokkaido, Japan. [Thouret, V.] CNRS, Lab Aerol, Toulouse, France. [Posny, F.] Lab Phys Atmosphere La Reunion, La Reunion, France. [Morris, G.] Valparaiso Univ, Dept Phys & Astron, Valparaiso, IN 46383 USA. [Merrill, J.] Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. [Leong, C. P.] Malaysian Meteorol Serv, Selangor, Malaysia. [Koenig-Langlo, G.] Alfred Wegener Inst Polar & Marine Res, Bremerhaven, Germany. [Joseph, E.] Howard Univ, Climate & Radiat Grp, Washington, DC 20059 USA. RP Schoeberl, MR (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Duncan, Bryan/A-5962-2011; Fujiwara, Masatomo/F-7852-2012; Strahan, Susan/H-1965-2012; andersen, signe/C-4809-2013; von der Gathen, Peter/B-8515-2009; Redondas, Alberto/L-9299-2015; Cuevas, Emilio/L-2109-2013; Konig-Langlo, Gert/K-5048-2012; Yela, Margarita/J-7346-2016; Thompson, Anne /C-3649-2014 OI andersen, signe/0000-0002-8216-0141; von der Gathen, Peter/0000-0001-7409-1556; Redondas, Alberto/0000-0002-4826-6823; Cuevas, Emilio/0000-0003-1843-8302; Konig-Langlo, Gert/0000-0002-6100-4107; Yela, Margarita/0000-0003-3775-3156; Thompson, Anne /0000-0002-7829-0920 NR 31 TC 57 Z9 58 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 19 PY 2007 VL 112 IS D24 AR D24S49 DI 10.1029/2007JD008773 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 244PQ UT WOS:000251878200001 ER PT J AU Kota, AK Cipriano, BH Powell, D Raghavan, SR Bruck, HA AF Kota, Arun K. Cipriano, Bani H. Powell, Dan Raghavan, Srinivasa R. Bruck, Hugh A. TI Quantitative characterization of the formation of an interpenetrating phase composite in polystyrene from the percolation of multiwalled carbon nanotubes SO NANOTECHNOLOGY LA English DT Article ID OF-MIXTURES PREDICTIONS; NANOTUBE/POLYMER COMPOSITES; RHEOLOGICAL BEHAVIOR; NI-AL2O3 COMPOSITES; EPOXY COMPOSITES; NANOCOMPOSITES; SUSPENSIONS; POLYCARBONATE; CONDUCTIVITY; POLYETHYLENE AB For the first time, an interpenetrating phase polymer nanocomposite formed by the percolation of multiwalled carbon nanotubes (MWCNTs) in polystyrene (PS) has been quantitatively characterized through electrical conductivity measurements and melt theology. Both sets of measurements, in conjunction with scanning electron microscopy (SEM) images, indicate the presence of a continuous phase of percolated MWCNTs appearing at particle concentrations exceeding 2 vol% MWCNTs in PS. To quantify the amount of this continuous phase present in the PS/MWCNT composite, electrical conductivity data at various MWCNT concentrations, beta, are correlated with a proposed degree of percolation, (C) over bar(beta), developed using a conventional power-law formula with and without a percolation threshold. To quantify the properties of the interpenetrating phase polymer nanocomposite, the PS/MWCNT composite is treated as a combination of two phases: a continuous phase consisting of a pseudo-solid-like network of percolated MWCNTs, and a continuous PS phase reinforced by non-interacting MWCNTs. The proposed degree of percolation is used to quantify the distribution of MWCNTs among the phases, and is then used in a rule-of-mixtures formulation for the storage modulus, G'(beta, (C) over bar(beta), omega), and the loss modulus, G"(beta, (C) over bar(beta), omega), to quantify the properties of the continuous phase consisting of percolated MWCNTs and the continuous PS phase reinforced by non-interacting MWCNTs from the experimental melt theology data. The properties of the continuous phase of percolated MWCNTs are indicative of a scaffold-like microstructure exhibiting an elastic behavior with a complex modulus of 360 kPa at lower frequencies and viscoplastic behavior with a complex viscosity of 6 kPa s rad(-1) at higher frequencies, most likely due to a stick-slip friction mechanism at the interface of the percolated MWCNTs. Additional evidence of this microstructure was obtained via scanning electron microscopy. This research has important implications in providing a new methodology based on the electrical and theological properties of the polymer nanocomposite for quantifying the continuous phase formed by the percolation of new functionalized nanostructures being developed for: (a) controlling the percolation of the nanostructures through self-assembly, (b) enhancing their interaction with the continuous reinforced polymer phase, (c) enhancing the cohesion between nanostructures. C1 [Kota, Arun K.; Bruck, Hugh A.] Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. [Cipriano, Bani H.; Raghavan, Srinivasa R.] Univ Maryland, Dept Chem & Biomol Engn, College Pk, MD 20742 USA. [Powell, Dan] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bruck, HA (reprint author), Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. EM bruck@eng.umd.edu RI Cipriano, Bani/G-9239-2011 NR 32 TC 21 Z9 21 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 EI 1361-6528 J9 NANOTECHNOLOGY JI Nanotechnology PD DEC 19 PY 2007 VL 18 IS 50 AR 505705 DI 10.1088/0957-4494/18/50/505705 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 256QV UT WOS:000252745600015 ER PT J AU Kim, MK Lau, WKM Kim, KM Lee, WS AF Kim, Maeng-Ki Lau, William K. M. Kim, Kyu-Myong Lee, Woo-Seop TI A GCM study of effects of radiative forcing of sulfate aerosol on large scale circulation and rainfall in East Asia during boreal spring SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SUMMER MONSOON; LAND-SURFACE; PRECIPITATION; CHINA; CLIMATE; MODELS; CLOUDS AB The effect of sulfate aerosol radiative forcing on spring rainfall in East Asia are studied based on numerical simulations with the NASA finite-volume General Circulation Model (fvGCM) forced with monthly varying three-dimensional aerosol distribution from the Goddard Ozone Chemistry Aerosol Radiation and Transport model (GOCART). Result shows that radiative forcing of sulfate aerosol leads to cooling of the land surface and reduction in rainfall over central East Asia. The maximum reduction in precipitation is shifted northward relative to the maximum aerosol loading region as a result of dynamical feedback. The anomalous thermal gradient by aerosol cooling near the land surface, reduces the baroclinicity of the atmosphere, leading to a deceleration of the upper level westerly flow. The westerly deceleration induces, through ageostrophic wind adjustment, anomalous meridional secondary circulation at the entrance region of the East Asian jetstream, with strong sinking motion and suppressed precipitation near 30 degrees N, coupled to weak rising motion and moderately enhanced precipitation over southern China and the South China Sea. These results suggest that the radiative forcing of aerosol through induced dynamical feedback with the atmospheric water cycle, may be a causal factor in the observed spring precipitation trend over East Asia. C1 [Kim, Maeng-Ki; Lee, Woo-Seop] Kongju Natl Univ, Dept Atmospher Sci, Kong Ju, South Korea. [Lau, William K. M.] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD USA. [Kim, Kyu-Myong] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Kim, MK (reprint author), Kongju Natl Univ, Dept Atmospher Sci, 5523 Res Pk Dr,Suite 320, Kong Ju, South Korea. EM mkkim@kongju.ac.kr RI Kim, Kyu-Myong/G-5398-2014; Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 20 TC 30 Z9 32 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 18 PY 2007 VL 34 IS 24 AR L24701 DI 10.1029/2007GL031683 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 244PD UT WOS:000251876900004 ER PT J AU Christensen, LE Brunner, B Truong, KN Mielke, RE Webster, CR Coleman, M AF Christensen, Lance E. Brunner, Benjamin Truong, Kasey N. Mielke, Randall E. Webster, Christopher R. Coleman, Max TI Measurement of sulfur isotope compositions by tunable laser spectroscopy of SO2 SO ANALYTICAL CHEMISTRY LA English DT Article ID DIODE-LASER; SPECTROMETER; PRECISION; ORIGIN; WATER; SURFACES; METHANE; RATIOS; MARS AB Sulfur isotope measurements offer comprehensive information on the origin and history of natural materials. Tunable laser spectroscopy is a powerful analytical technique for isotope analysis that has proven itself readily adaptable for in situ terrestrial and planetary measurements. Measurements of delta S-34 in SO2 were made using tunable laser spectroscopy of combusted gas samples from six sulfur-bearing solids with delta S-34 ranging from -34 to +22%o (also measured with mass spectrometry). Standard deviation between laser and mass spectrometer measurements was 3.7 parts per thousand for sample sizes of 200 75 nmol SO2. Although SO2(g) decreased 9% over 15 min upon entrainment in the analysis cell from wall uptake, observed fractionation was insignificant (+0.2 +/- 0.6 parts per thousand). We also describe a strong, distinct (SO2)-S-33 rovibrational transition in the same spectral region, which may enable simultaneous delta S-34 and Delta S-33 measurements. C1 [Christensen, Lance E.; Brunner, Benjamin; Truong, Kasey N.; Mielke, Randall E.; Webster, Christopher R.; Coleman, Max] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Christensen, LE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Christensen@jpl.nasa.gov RI Barker, Shaun/A-4740-2008; Brunner, Benjamin/F-2027-2011 NR 38 TC 13 Z9 14 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 15 PY 2007 VL 79 IS 24 BP 9261 EP 9268 DI 10.1021/ac071040p PG 8 WC Chemistry, Analytical SC Chemistry GA 241PD UT WOS:000251667400003 PM 18020312 ER PT J AU Nielsen, SG Rehkamper, M Brandon, AD Norman, MD Turner, S O'Reilly, SY AF Nielsen, Sune G. Rehkamper, Mark Brandon, Alan D. Norman, Marc D. Turner, Simon O'Reilly, Suzanne Y. TI Thallium isotopes in Iceland and Azores lavas - Implications for the role of altered crust and mantle geochemistry SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE mantle plume; crustal recycling; thallium isotopes; stable isotopes; ocean island basalts ID TRACE-ELEMENTS; SAO-MIGUEL; FERROMANGANESE CRUSTS; OCEANIC-CRUST; EARTHS MANTLE; MASS-BALANCE; PB ISOTOPE; MC-ICPMS; PLUME; BASALTS AB Mantle plumes are commonly perceived to have both a chemical and dynamic link with the subduction of ocean crust into the mantle. In principle, this should lead to the observation of chemical and isotopic signatures that are characteristic of ocean crust and marine sediments in ocean island basalts. This study investigates the thallium (Tl) isotope systematics of lavas from Iceland and the Azores archipelago, in order to determine if their compositions were affected by admixing of ferromanganese sediments or upper ocean crust altered at low temperature. Such materials are known to display strongly fractionated Tl isotope signatures relative to the ambient upper mantle. Two samples from the island of Terceira in the Azores archipelago have Tl isotope compositions significantly different from normal mantle, and this suggests the presence of Fe-Mn sediments. Combined Pb and Tl isotope modelling indicates that the Tl anomalies are not a feature of the Azores plume but produced by assimilation of modem Fe-Mn sediments during magma ascent through the ocean crust. Excluding these two anomalous lavas from Terceira, the Iceland and Azores samples have identical Tl isotope compositions, with an overall mean of epsilon(205)Tl=- 1.5 +/- 1.4 (2SD, n=30) that is indistinguishable from the previously estimated upper mantle average (epsilon(205)Tl=-2.0 +/- 0.5). The near-constant Tl isotope compositions of the Iceland and Azores lavas may indicate that the respective mantle plume sources contain virtually no Fe-Mn sediments or altered upper ocean crust. Alternatively, it is possible that the lack of Tl isotope variation reflects quantitative removal of fractionated Tl from the slab during subduction and dehydration. A less straightforward explanation is that past marine environments produced sediments and altered marine basalts with nearly unfractionated Tl isotope compositions. All three scenarios have important implications and future Tl isotope studies will be able to identify the most feasible interpretation. (C) 2007 Elsevier B.V. All fights reserved. C1 [Nielsen, Sune G.] Univ Oxford, Dept Earth Sci, Oxford OX1 3PR, England. [Nielsen, Sune G.; Turner, Simon; O'Reilly, Suzanne Y.] Macquarie Univ, Dept Earth & Planetary Sci, GEMOC, N Ryde, NSW 2109, Australia. [Rehkamper, Mark] Univ London Imperial Coll Sci Technol & Med, Dept Earth Sci & Engn, London SW7 2AZ, England. [Brandon, Alan D.] NASA, Johnson Space Ctr, Houston, TX 77058 USA. [Norman, Marc D.] Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 0200, Australia. RP Nielsen, SG (reprint author), Univ Oxford, Dept Earth Sci, Parks Rd, Oxford OX1 3PR, England. EM sunen@ear-th.ox.ac.uk RI Norman, Marc/A-2244-2008; Nielsen, Sune/C-7345-2011; GAU, geochemist/H-1985-2016; OI Nielsen, Sune/0000-0002-0458-3739; O'Reilly, Suzanne Y/0000-0002-3883-5498; Rehkamper, Mark/0000-0002-0075-9872 NR 52 TC 24 Z9 29 U1 1 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD DEC 15 PY 2007 VL 264 IS 1-2 BP 332 EP 345 DI 10.1016/j.epsi.2007.10.008 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 244UM UT WOS:000251890800026 ER PT J AU Bridges, NT Geissler, PE McEwen, AS Thomson, BJ Chuang, FC Herkenhoff, KE Keszthelyi, LP Martinez-Alonso, S AF Bridges, N. T. Geissler, P. E. McEwen, A. S. Thomson, B. J. Chuang, F. C. Herkenhoff, K. E. Keszthelyi, L. P. Martinez-Alonso, S. TI Windy Mars: A dynamic planet as seen by the HiRISE camera SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MEDUSAE FOSSAE FORMATION; GLOBAL SURVEYOR; THERMAL INERTIA; ORBITER CAMERA; MOVEMENT; MISSION; REGION; MODEL AB With a dynamic atmosphere and a large supply of particulate material, the surface of Mars is heavily influenced by wind-driven, or aeolian, processes. The High Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter (MRO) provides a new view of Martian geology, with the ability to see decimeter-size features. Current sand movement, and evidence for recent bedform development, is observed. Dunes and ripples generally exhibit complex surfaces down to the limits of resolution. Yardangs have diverse textures, with some being massive at HiRISE scale, others having horizontal and cross-cutting layers of variable character, and some exhibiting blocky and polygonal morphologies. "Reticulate'' ( fine polygonal texture) bedforms are ubiquitous in the thick mantle at the highest elevations. C1 [Bridges, N. T.; Thomson, B. J.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. [Geissler, P. E.; Herkenhoff, K. E.; Keszthelyi, L. P.] US Geol Survey, Flagstaff, AZ 86001 USA. [McEwen, A. S.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. [Chuang, F. C.] Planetary Sci Inst, Tucson, AZ USA. [Martinez-Alonso, S.] Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA. RP Bridges, NT (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. EM nathan.bridges@jpl.nasa.gov RI Martinez-Alonso, Sara/D-8594-2011; Bridges, Nathan/D-6341-2016; OI Martinez-Alonso, Sara/0000-0001-5185-8670; Thomson, Bradley/0000-0001-8635-8932 NR 39 TC 41 Z9 42 U1 1 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 15 PY 2007 VL 34 IS 23 AR L23205 DI 10.1029/2007GL031445 PG 7 WC Geosciences, Multidisciplinary SC Geology GA 241XY UT WOS:000251690300001 ER PT J AU Safaeinili, A Kofman, W Mouginot, J Gim, YG Herique, A Ivanov, AB Plaut, JJ Picardi, G AF Safaeinili, Ali Kofman, Wlodek Mouginot, Jeremie Gim, Yonggyu Herique, Alain Ivanov, Anton B. Plaut, Jeffrey J. Picardi, Giovanni TI Estimation of the total electron content of the Martian ionosphere using radar sounder surface echoes SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAGNETIC-FIELD; MARS; SUBSURFACE; SOUNDINGS AB The Martian ionosphere's local total electron content (TEC) and the neutral atmosphere scale height can be derived from radar echoes reflected from the surface of the planet. We report the global distribution of the TEC by analyzing more than 750,000 echoes of the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS). This is the first direct measurement of the TEC of the Martian ionosphere. The technique used in this paper is a novel "transmission-mode'' sounding of the ionosphere of Mars in contrast to the Active Ionospheric Sounding experiment (AIS) on MARSIS, which generally operates in the reflection mode. This technique yields a global map of the TEC for the Martian ionosphere. The radar transmits a wideband chirp signal that travels through the ionosphere before and after being reflected from the surface. The received waves are attenuated, delayed and dispersed, depending on the electron density in the column directly below the spacecraft. In the process of correcting the radar signal, we are able to estimate the TEC and its global distribution with an unprecedented resolution of about 0.1 deg in latitude (similar to 5 km footprint). The mapping of the relative geographical variations in the estimated nightside TEC data reveals an intricate web of high electron density regions that correspond to regions where crustal magnetic field lines are connected to the solar wind. Our data demonstrates that these regions are generally but not exclusively associated with areas that have magnetic field lines perpendicular to the surface of Mars. As a result, the global TEC map provides a high-resolution view of where the Martian crustal magnetic field is connected to the solar wind. We also provide an estimate of the neutral atmospheric scale height near the ionospheric peak and observe temporal fluctuations in peak electron density related to solar activity. C1 [Safaeinili, Ali; Gim, Yonggyu; Ivanov, Anton B.; Plaut, Jeffrey J.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. [Kofman, Wlodek; Mouginot, Jeremie; Herique, Alain] CNRS, UJF, Lab Planetol Grenoble, F-38041 Grenoble, France. [Picardi, Giovanni] Univ Roma La Sapienza, Infocom Dept, Rome, Italy. RP Safaeinili, A (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. EM ali.safaeinili@jpl.nasa.gov RI Kofman, Wlodek/C-4556-2008; Ivanov, Anton/C-8944-2014; Mouginot, Jeremie/G-7045-2015; Herique, Alain/E-7210-2017 OI Ivanov, Anton/0000-0001-8376-8581; Herique, Alain/0000-0003-3699-883X NR 16 TC 59 Z9 61 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 15 PY 2007 VL 34 IS 23 AR L23204 DI 10.1029/2007GL032154 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 241XY UT WOS:000251690300007 ER PT J AU James, PB Thomas, PC Wolff, MJ Bonev, BP AF James, Philip B. Thomas, Peter C. Wolff, Michael J. Bonev, Boncho P. TI MOC observations of four Mars year variations in the south polar residual cap of Mars SO ICARUS LA English DT Article DE Mars, polar caps; Mars, polar geology; Mars, climate; Mars, atmosphere ID ORBITER CAMERA OBSERVATIONS; CARBON-DIOXIDE; WATER-VAPOR; ICE; ATMOSPHERE; VARIABILITY; EVOLUTION; FEATURES; MISSION; ALBEDO AB The residual south polar cap of Mars (RSPC) is distinct from the residual north polar cap both in composition and in morphology. CO(2) frost in the RSPC is stabilized by its high albedo during southern spring and summer despite the relatively large insolation during that period. The morphology of the RSPC in summer displays a bewildering variety of depressions that are formed in relatively thin layers Of CO(2). The increase of the size of these depressions between each of the first three years of Mars Global Surveyor (MGS) observations may possibly signal some sort of climate change on the planet. For example, the erosion of the bright plateaus might reduce the RSPC albedo and affect the energy balance. The Mars Orbiter Cameras (MOC) on MGS observed Mars for four consecutive martian years before contact with the spacecraft was lost in late 2006. During this period coverage of the polar regions was particularly dense because MGS flew over them on every orbit. In this paper we report on the four-year behavior of the morphological features in the RSPC and on the large-scale variability in RSPC albedo over the period. The changes in the size of the surface features in the RSPC due to backwasting that were first observed between Mars years (MY) 24 and 25 and subsequently between MY25 and M26 was observed to continue at the same rate through MY 27. The results indicate that on average thicker layers in the RSPC retreat faster than thinner ones, roughly in proportion to their thickness. We argue that a simple difference in porosity between the A and B layers can explain this difference although other factors could be involved. The large-scale albedo of the RSPC decreases as the depressions are uncovered by sublimation of seasonal CO(2). However, any interannual differences in albedo due to the backwasting process are masked by interannual differences in the summer dust opacity in the RSPC region. (c) 2007 Elsevier Inc. All rights reserved. C1 [James, Philip B.; Wolff, Michael J.] Space Sci Inst, Boulder, CO 80301 USA. [Thomas, Peter C.] Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. [Bonev, Boncho P.] Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. [Bonev, Boncho P.] NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RP James, PB (reprint author), Space Sci Inst, 4750 Walnut St,Suite 205, Boulder, CO 80301 USA. EM pjames@cableone.net NR 32 TC 7 Z9 7 U1 0 U2 10 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC 15 PY 2007 VL 192 IS 2 BP 318 EP 326 DI 10.1016/j.icarus.2007.07.014 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 244EU UT WOS:000251850000002 ER PT J AU Lewis, SR Read, PL Conrath, BJ Pearl, JC Smith, MD AF Lewis, Stephen R. Read, Peter L. Conrath, Barney J. Pearl, John C. Smith, Michael D. TI Assimilation of thermal emission spectrometer atmospheric data during the Mars Global Surveyor aerobraking period SO ICARUS LA English DT Article DE Mars, atmosphere; atmospheres, dynamics; meteorology ID GENERAL-CIRCULATION MODEL; RADIO OCCULTATION MEASUREMENTS; TES NADIR DATA; MARTIAN ATMOSPHERE; MAPPER OBSERVATIONS; METEOROLOGICAL DATA; POLAR-REGIONS; DUST STORMS; INERTIA; ALBEDO AB The Thermal Emission Spectrometer aboard the Mars Global Surveyor spacecraft has produced an extensive atmospheric data set, beginning during aerobraking and continuing throughout the extended scientific mapping phase. Temperature profiles for the atmosphere below about 40 kin, surface temperatures and total dust and water ice opacities, can be retrieved from infrared spectra in nadir viewing mode. This paper describes assimilation of nadir retrievals from the spacecraft aerobraking period, L(S) = 190 degrees-260 degrees, northern hemisphere autumn to winter, into a Mars general Circulation model. The assimilation scheme is able to combine information from temperature and dust optical. depth retrievals, making use of a model forecast containing information from the assimilation of earlier observations, to obtain a global, time-dependent analysis. Given sufficient temperature retrievals, the assimilation procedure indicates errors in the a priori dust distribution assumptions even when lacking dust observations; in this case there are relatively cold regions above the poles compared to a model which assumes a horizontally-uniform dust distribution. One major reason for using assimilation techniques is in order to investigate the transient wave behavior on Mars. Whilst the data from the 2-h spacecraft mapping orbit phase is touch more suitable for assimilation, even the longer (45-24 h) period aerobraking orbit data contain useful information about the three-dimensional synoptic-scale martian circulation which the assimilation procedure can reconstruct in a consistent way. Assimilations from the period of the Noachis regional dust storm demonstrate that the combined assimilation of temperature and dust retrievals has a beneficial impact on the atmospheric analysis. (c) 2007 Elsevier Inc. All rights reserved. C1 [Lewis, Stephen R.] Open Univ, Dept Phys & Astron, Walton Hall, Milton Keynes MK7 6AA, Bucks, England. [Read, Peter L.] Clarendon Lab, Oxford OX1 3PU, England. [Conrath, Barney J.] Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. [Pearl, John C.; Smith, Michael D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lewis, SR (reprint author), Open Univ, Dept Phys & Astron, Walton Hall, Milton Keynes MK7 6AA, Bucks, England. EM s.r.lewis@open.ac.uk RI Smith, Michael/C-8875-2012; OI Lewis, Stephen/0000-0001-7237-6494 NR 38 TC 36 Z9 36 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC 15 PY 2007 VL 192 IS 2 BP 327 EP 347 DI 10.1016/j.icarus.2007.08.009 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 244EU UT WOS:000251850000003 ER PT J AU Inada, A Richardson, MI McConnochie, TH Strausberg, MJ Wang, HQ Bell, JF AF Inada, Ai Richardson, Mark I. McConnochie, Timothy H. Strausberg, Melissa J. Wang, Huiqun Bell, James F., III TI High-resolution atmospheric observations by the Mars Odyssey Thermal Emission Imaging System SO ICARUS LA English DT Article DE Mars, atmosphere; Mars, polar caps ID CO2 ICE CLOUDS; MARTIAN ATMOSPHERE; ORBITER CAMERA; POLAR-CAP; SURFACE; DUST; WINDS; MISSION; THEMIS; STORM AB High-resolution observations of atmospheric phenomena by the Mars Odyssey Thermal Emission Imaging System (THEMIS) during its first mapping year are presented. An atmospheric campaign was implemented on the basis of previous spacecraft imaging. This campaign, however, proved of limited success. This appears to be due to the late local time of the Odyssey orbit (the locations of activity at 4-6 p.m. appear to be different from those at 2 p.m.). Ironically, images targeting the surface were more useful for study of the atmosphere than those images specifically targeting atmospheric features. While many previously recognized features were found, novel THEMIS observations included persistent clouds in the southern polar layered deposits, dust or condensate plumes on the northern polar layered deposits, dust plumes as constituent parts of local dust storms, and mesospheric clouds. The former two features tend to be aligned parallel and normal to polar troughs, respectively, suggesting a wind system directed normal to troughs and radially outward from the center of the polar deposits. This is consistent with katabatic drainage of air off the polar deposits, analogous to flow off Antarctica. The observation of dust lifting plumes at unprecedented resolution associated with local dust storms not only demonstrates the importance of mean wind stresses (as opposed to dust devils) in initiation of dust storms, but is also seen to be morphologically identical to dust lifting in terrestrial dust storms. As Odyssey moves to earlier local times, we suggest that the atmospheric campaign from the first mapping year be repeated. (c) 2007 Elsevier Inc. All rights reserved. C1 [Inada, Ai; Richardson, Mark I.] CALTECH, Pasadena, CA 91125 USA. [McConnochie, Timothy H.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Strausberg, Melissa J.] Univ Calif Los Angeles, Los Angeles, CA 90095 USA. [Wang, Huiqun] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Bell, James F., III] Cornell Univ, Space Sci Bldg, Ithaca, NY 14853 USA. RP Inada, A (reprint author), CALTECH, MS 150-21,1200 E California Blvd, Pasadena, CA 91125 USA. EM inada@gps.caltech.edu NR 53 TC 13 Z9 13 U1 1 U2 4 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC 15 PY 2007 VL 192 IS 2 BP 378 EP 395 DI 10.1016/j.icarus.2007.07.020 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 244EU UT WOS:000251850000006 ER PT J AU Krasnopolsky, VA Maillard, JP Owen, TC Toth, RA Smith, MD AF Krasnopolsky, Vladimir A. Maillard, Jean Pierre Owen, Tobias C. Toth, Robert A. Smith, Michael D. TI Oxygen and carbon isotope ratios in the martian atmosphere SO ICARUS LA English DT Article DE Mars; Mars, atmosphere; atmospheres; evolution; spectroscopy ID WATER-VAPOR; MU-M; MARS; SPECTROSCOPY; DEUTERIUM; SURFACE; SEARCH; HDO; CH4 AB Oxygen and carbon isotope ratios in the martian CO2 are key values to study evolution of volatiles on Mars. The major problems in spectroscopic determinations of these ratios on Mars are uncertainties associated with: (I) equivalent widths of the observed absorption lines, (2) line strengths in spectroscopic databases, and (3) thermal structure of the martian atmosphere during the observation. We have made special efforts to reduce all these uncertainties. We observed Mars using the Fourier Transform Spectrometer at the Canada-France-Hawaii Telescope. While the oxygen and carbon isotope ratios on Mars were byproducts in the previous observations, our observation was specifically aimed at these isotope ratios. We covered a range of 6022 to 6308 cm(-1) with the highest resolving power of v/delta v = 3.5 x 105 and a signal-to-noise ratio of 180 in the middle of the spectrum. The chosen spectral range involves 475 lines of the main isotope, 184 lines of (CO2)-C-13, 181 lines of (COO)-O-18, and 119 lines of (COO)-O-17. (Lines with strengths exceeding 10(-27) cm at 218 K are considered here.) Due to the high spectral resolution, most of the lines are not blended. Uncertainties of retrieved isotope abundances are in inverse proportion to resolving power, signal-to-noise ratio, and square root of the number of lines. Laboratory studies of the CO2 isotope spectra in the range of our observation achieved an accuracy of similar to 1% in the line strengths. Detailed observations of temperature profiles using MGS/TES and data on temperature variations with local time from two GCMs are used to simulate each absorption line at various heights in each part of the instrument field of view and then sum up the results. Thermal radiation of Mars' surface and atmosphere is negligible in the chosen spectral range, and this reduces errors associated with uncertainties in the thermal structure on Mars. Using a combination of all these factors, the highest accuracy has been achieved in measuring the CO2 isotope ratios: C-13/C-12 = 0.978 +/- 0.020 and O-18/O-16 = 1.018 +/- 0.018 times the terrestrial standards. Heavy isotopes in the atmosphere are enriched by nonthermal escape and sputtering, and depleted by fractionation with solid-phase reservoirs. The retrieved ratios show that isotope fractionation between CO2 and oxygen and carbon reservoirs in the solid phase is almost balanced by nonthermal escape and sputtering of O and C from Mars. (c) 2007 Elsevier Inc. All rights reserved. C1 [Krasnopolsky, Vladimir A.] Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. [Maillard, Jean Pierre] Inst Astrophys, CNRS, F-75014 Paris, France. [Owen, Tobias C.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. [Toth, Robert A.] Jet Propuls Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. [Smith, Michael D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Krasnopolsky, VA (reprint author), Dept Phys, 6100 Westchester Pk Dr No911, College Pk, MD 20740 USA. EM vkrasn@verizon.net RI Smith, Michael/C-8875-2012; Krasnopolsky, Vladimir/L-5085-2013 NR 25 TC 20 Z9 20 U1 1 U2 6 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 EI 1090-2643 J9 ICARUS JI Icarus PD DEC 15 PY 2007 VL 192 IS 2 BP 396 EP 403 DI 10.1016/j.icarus.2007.08.013 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 244EU UT WOS:000251850000007 ER PT J AU Moores, JE Smith, PH Tanner, R Schuerger, AC Venkateswaran, KJ AF Moores, J. E. Smith, P. H. Tanner, R. Schuerger, A. C. Venkateswaran, K. J. TI The shielding effect of small-scale martian surface geometry on ultraviolet flux SO ICARUS LA English DT Article DE Mars, surface; astrobiology; photochemistry; radiative transfer ID SPACECRAFT ASSEMBLY FACILITY; ABSORPTION CROSS-SECTIONS; HAWAIIAN PALAGONITIC SOIL; MARS PATHFINDER; MAGNETIC-PROPERTIES; BACILLUS-SUBTILIS; UV-IRRADIATION; ATMOSPHERE; RADIATION; ENVIRONMENT AB The atmosphere of Mars does little to attenuate incoming ultraviolet (UV) radiation. Large amounts of UV radiation sterilize the hardiest of terrestrial organisms within minutes, and chemically alter the soil such that organic molecules at or near the surface are rapidly destroyed. Thus the survival of any putative martian life near the surface depends to a large extent on how much UV radiation it receives. Variations in small-scale geometry of the surface such as pits, trenches, flat faces and overhangs can have a significant effect on the incident UV flux and may create "safe havens" for organisms and organic molecules. In order to examine this effect, a I-D radiative transfer sky model with 836 meshed points (plus the Sun) was developed which includes both diffuse and direct components of the surface irradiance. This model derives the variation of UV flux with latitude and an object's Geometric Shielding Ratio (a ratio which describes the geometry of each situation). The best protection is offered by overhangs with flux reduced to a factor of 1.8 +/- 0.2 x 10(-5) of the unprotected value, a reduction which does not vary significantly by latitude. Pits and cracks are less effective with a reduction in UV flux of only up to 4.5 +/- 0.5 x 10(-3) for the modeled scenarios; however, they are more effective for the same geometric shielding ratio than overhangs at high latitudes due to the low height of the Sun in the sky. Lastly, polar faces of rocks have the least effective shielding geometry with at most a 1.1 +/- 0.1 x 10(-1) reduction in UV flux. Polar faces of rocks are most effective at mid latitudes where the Sun is never directly overhead, as at tropical latitudes, and never exposes the back of the rock, as at polar latitudes. In the most favorable cases, UV flux is sufficiently reduced such that organic in-fall could accumulate beneath overhanging surfaces and in pits and cracks. As well, hardy terrestrial microorganisms such as Bacillus pumilus could persist for up to 100 sols on the outer surfaces of typical spacecraft or several tens of martian years in the most shielded surface niches. Published by Elsevier Inc. C1 [Moores, J. E.; Smith, P. H.; Tanner, R.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. [Schuerger, A. C.] Univ Florida, Dept Plant Pathol, Kennedy Space Ctr, FL 32899 USA. [Venkateswaran, K. J.] Jet Propuls Lab, Pasadena, CA 91109 USA. RP Moores, JE (reprint author), Univ Arizona, Lunar & Planetary Lab, 1629 E Univ Blvd, Tucson, AZ 85721 USA. EM jmoores@lpl.arizona.edu NR 55 TC 29 Z9 29 U1 0 U2 7 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC 15 PY 2007 VL 192 IS 2 BP 417 EP 433 DI 10.1016/j.icarus.2007.07.003 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 244EU UT WOS:000251850000009 ER PT J AU Rubincam, DP AF Rubincam, David Parry TI Orbital YORP and asteroid orbit evolution, with application to Apophis SO ICARUS LA English DT Article DE asteroids; asteroids; dynamics; asteroids; rotation; asteroids; surfaces ID RADIATION PRESSURE; EARTH; YARKOVSKY; DYNAMICS AB Photon thrust from shape alone can produce quasi-secular changes in an asteroid's orbital elements. An asteroid in an elliptical orbit with a north-south shape asymmetry can steadily alter its elements over timescales longer than one orbital trip about the Sun. This thrust, called here orbital YORP (YORP = Yarkovsky-O'Keefe-Radzievskii-Paddack), operates even in the absence of thermal inertia, which the Yarkovsky effects require. However, unlike the Yarkovsky effects, which produce secular orbital changes over millions or billions of years, the change in an asteroid's orbital elements from orbital YORP operates only over the precession timescale of the orbit or of the asteroid's spin axis; this is generally only thousands or tens of thousands of years. Thus while the orbital YORP timescale is too short for an asteroid to secularly journey very far, it is long enough to warrant investigation with respect to 99942 Apophis, which might conceivably impact the Earth in 2036. A near-maximal orbital YORP effect is found by assuming Apophis is without thermal inertia and is shaped like a hemisphere, with its spin axis lying in the orbital plane. With these assumptions orbital YORP can change its along-track position by up to 245 km, which is comparable to Yarkovsky effects. Though Apophis' shape, thermal properties, and spin axis orientation are currently unknown, the practical upper and lower limits are liable to be much less than the 245 km extremes. Even so, the uncertainty in position is still likely to be much larger than the similar to 0.5 km "keyhole" Apophis must pass through during its close approach in 2029 in order to strike the Earth in 2036. Published by Elsevier Inc. C1 [Rubincam, David Parry] NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Planetary Geodynam Lab, Greenbelt, MD 20771 USA. RP Rubincam, DP (reprint author), NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Planetary Geodynam Lab, Greenbelt, MD 20771 USA. EM david.p.rubincam@nasa.gov RI Rubincam, David/D-2918-2012 NR 25 TC 5 Z9 5 U1 1 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC 15 PY 2007 VL 192 IS 2 BP 460 EP 468 DI 10.1016/j.icarus.2007.07.010 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 244EU UT WOS:000251850000013 ER PT J AU Keszthelyi, L Jaeger, W Milazzo, M Radebaugh, J Davies, AG Mitchell, KL AF Keszthelyi, Laszlo Jaeger, Windy Milazzo, Moses Radebaugh, Jani Davies, Ashley Gerard Mitchell, Karl L. TI New estimates for Io eruption temperatures: Implications for the interior SO ICARUS LA English DT Article DE Io; volcanism; interiors ID HEAT-FLOW; RHEOLOGICAL PROPERTIES; THERMODYNAMIC MODEL; VISCOELASTIC MODELS; SILICATE VOLCANISM; THERMAL EMISSION; ACTIVE VOLCANISM; TVASHTAR CATENA; HOT-SPOTS; LAVA AB The initial interpretation of Galileo data from Jupiter's moon, to, suggested eruption temperatures >= 1600 degrees C. Tidal heating models have difficulties explaining Io's prodigious heat flow if the mantle is > 1300 degrees C, although we suggest that temperatures up to similar to 1450 degrees C may be possible. In general, Io eruption temperatures have been overestimated because the incorrect thermal model has been applied. Much of the thermal emission from high-temperature hot spots comes from lava fountains but lava flow models were utilized. We apply a new lava fountain model to the highest reported eruption temperature, the SSI observation of the 1997 eruption at Pillan. This resets the lower temperature limit for the eruption from similar to 1600 to similar to 1340 degrees C. Additionally, viscous heating of the magma may have increased eruption temperature by -50-100 degrees C as a result of the strong compressive stresses in the ionian lithosphere. While further work is needed, it appears that the discrepancy between observations and interior models is largely resolved. (c) 2007 Elsevier Inc. All rights reserved. C1 [Keszthelyi, Laszlo; Jaeger, Windy] US Geol Survey, Astrogeol Team, Flagstaff, AZ 86001 USA. [Milazzo, Moses] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. [Radebaugh, Jani] Brigham Young Univ, Dept Geol Sci, Provo, UT 84602 USA. [Davies, Ashley Gerard; Mitchell, Karl L.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Keszthelyi, L (reprint author), US Geol Survey, Astrogeol Team, 2255 N Gemini Dr, Flagstaff, AZ 86001 USA. EM laz@usgs.gov NR 58 TC 32 Z9 32 U1 0 U2 8 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC 15 PY 2007 VL 192 IS 2 BP 491 EP 502 DI 10.1016/j.icarus.2007.07.008 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 244EU UT WOS:000251850000016 ER PT J AU Glotch, TD Rossman, GR Aharonson, O AF Glotch, Timothy D. Rossman, George R. Aharonson, Oded TI Mid-infrared (5-100 mu m) reflectance spectra and optical constants of ten phyllosilicate minerals SO ICARUS LA English DT Review DE spectroscopy; infrared observations; Mars; asteroids; observations disks; interplanetary dust ID LOW-ALBEDO ASTEROIDS; BETA-PICTORIS DISK; FINE-GRAINED RIMS; CARBONACEOUS CHONDRITE; AQUEOUS ALTERATION; INFRARED REFLECTANCE; THERMAL EMISSION; PARTICULATE SURFACES; PLANETARY REGOLITHS; CIRCUMSTELLAR DISK AB We have derived the real and imaginary indices of refraction for 10 phyllosilicate minerals-montinorillonite, beidellite, nontronite, hectorite, saponite, illite, illite-smectite (60/40 interlayered) kaolinite, halloysite, and serpentine-from 100-2000 cm(-1) (5-100 mu m) at 2 cm(-1) spectral sampling using classical Lorentz-Lorenz dispersion theory. We present the real and imaginary indices and the oscillator parameters with which they were modeled. Use of these optical constants will aid in the modeling of thermal infrared spectra of planets, asteroids, interplanetary and interstellar dust, and protoplanetary disks around nearby stars. (c) 2007 Elsevier Inc. All rights reserved. C1 [Glotch, Timothy D.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. [Rossman, George R.; Aharonson, Oded] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Glotch, TD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. EM tglotch@notes.ce.sunysb.edu RI Glotch, Timothy/B-6829-2008; OI Rossman, George/0000-0002-4571-6884 NR 113 TC 29 Z9 29 U1 1 U2 21 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 EI 1090-2643 J9 ICARUS JI Icarus PD DEC 15 PY 2007 VL 192 IS 2 BP 605 EP 622 DI 10.1016/j.icarus.2007.07.002 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 244EU UT WOS:000251850000024 ER PT J AU Noble, SK Pieters, CM Keller, LP AF Noble, Sarah K. Pieters, Carle M. Keller, Lindsay P. TI An experimental approach to understanding the optical effects of space weathering SO ICARUS LA English DT Article DE asteroids; surfaces; moon; surface; mercury; spectroscopy ID REFLECTANCE SPECTRA; FINEST FRACTION; AIRLESS BODIES; LUNAR SOIL; MERCURY; REGOLITHS; SURFACE; METEORITES; POWDERS; MOON AB The creation and accumulation of nanophase iron (npFe(0)) is a principal mechanism by which spectra of materials exposed to the space environinent incur systematic changes referred to as "space weathering." Since there is no reason to assume that cumulative space weathering products throughout the Solar System will be the same as those found in lunar soils, these products are likely to be very dependent on the specific environmental conditions under which they were produced. We have prepared a suite of analog soils to explore the optical effects of npFe(0). By varying the size and concentration of npFe(0) in the analogs we found significant systematic changes in the Vis/NIR spectral properties of the materials. Smaller npFe(0) (< 10 nm in diameter) dramatically reddens spectra in the visible wavelengths while leaving the infrared region largely unaffected. Larger npFe(0) (> 40 nm in diameter) lowers the albedo across the Vis/NIR range with little change in the overall shape of the continuum. Intermediate npFe(0) sizes impact the spectra in a distinct pattern that changes with concentration. The products of these controlled experiments have implications for space-weathered material throughout the inner Solar System. Our results indicate that the lunar soil continuum is best modeled by npFe(0) particles with bulk properties in the similar to 15-25 nm size range. Larger npFe(0), grains result in spectra that are similar in shape to the Mercury continuum. The continuum of S-type asteroid spectra appear to be best represented by low abundances of npFe(0). The size of asteroidal npFe(0) is similar to that of lunar soils, but slightly smaller on average (similar to 10-15 nm). (c) 2007 Elsevier Inc. All rights reserved. C1 [Noble, Sarah K.; Pieters, Carle M.] Brown Univ, Providence, RI 02912 USA. [Keller, Lindsay P.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Noble, SK (reprint author), Brown Univ, Providence, RI 02912 USA. EM sarah.k.noble@nasa.gov RI Noble, Sarah/D-7614-2012 NR 43 TC 110 Z9 112 U1 2 U2 11 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC 15 PY 2007 VL 192 IS 2 BP 629 EP 642 DI 10.1016/j.icarus.2007.07.021 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 244EU UT WOS:000251850000026 ER PT J AU Jiang, YB Froidevaux, L Lambert, A Livesey, NJ Read, WG Waters, JW Bojkov, B Leblanc, T McDermid, IS Godin-Beekmann, S Filipiak, MJ Harwood, RS Fuller, RA Daffer, WH Drouin, BJ Cofield, RE Cuddy, DT Jarnot, RF Knosp, BW Perun, VS Schwartz, MJ Snyder, WV Stek, PC Thurstans, RP Wagner, PA Allaart, M Andersen, SB Bodeker, G Calpini, B Claude, H Coetzee, G Davies, J De Backer, H Dier, H Fujiwara, M Johnson, B Kelder, H Leme, NP Konig-Langlo, G Kyro, E Laneve, G Fook, LS Merrill, J Morris, G Newchurch, M Oltmans, S Parrondos, MC Posny, F Schmidlin, F Skrivankova, P Stubi, R Tarasick, D Thompson, A Thouret, V Viatte, P Vomel, H von Der Gathen, P Yela, M Zablocki, G AF Jiang, Y. B. Froidevaux, L. Lambert, A. Livesey, N. J. Read, W. G. Waters, J. W. Bojkov, B. Leblanc, T. McDermid, I. S. Godin-Beekmann, S. Filipiak, M. J. Harwood, R. S. Fuller, R. A. Daffer, W. H. Drouin, B. J. Cofield, R. E. Cuddy, D. T. Jarnot, R. F. Knosp, B. W. Perun, V. S. Schwartz, M. J. Snyder, W. V. Stek, P. C. Thurstans, R. P. Wagner, P. A. Allaart, M. Andersen, S. B. Bodeker, G. Calpini, B. Claude, H. Coetzee, G. Davies, J. De Backer, H. Dier, H. Fujiwara, M. Johnson, B. Kelder, H. Leme, N. P. Koenig-Langlo, G. Kyro, E. Laneve, G. Fook, L. S. Merrill, J. Morris, G. Newchurch, M. Oltmans, S. Parrondos, M. C. Posny, F. Schmidlin, F. Skrivankova, P. Stubi, R. Tarasick, D. Thompson, A. Thouret, V. Viatte, P. Vomel, H. von Der Gathen, P. Yela, M. Zablocki, G. TI Validation of Aura Microwave Limb Sounder Ozone by ozonesonde and lidar measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ZONAL WAVE-ONE; STRATOSPHERIC OZONE; EOS MLS; VERTICAL-DISTRIBUTION; REMOTE MEASUREMENTS; RADIATIVE-TRANSFER; PROFILES; MODEL; CLIMATOLOGY; TEMPERATURE AB [1] We present validation studies of MLS version 2.2 upper tropospheric and stratospheric ozone profiles using ozonesonde and lidar data as well as climatological data. Ozone measurements from over 60 ozonesonde stations worldwide and three lidar stations are compared with coincident MLS data. The MLS ozone stratospheric data between 150 and 3 hPa agree well with ozonesonde measurements, within 8% for the global average. MLS values at 215 hPa are biased high compared to ozonesondes by similar to 20% at middle to high latitude, although there is a lot of variability in this altitude region. Comparisons between MLS and ground-based lidar measurements from Mauna Loa, Hawaii, from the Table Mountain Facility, California, and from the Observatoire de Haute-Provence, France, give very good agreement, within similar to 5%, for the stratospheric values. The comparisons between MLS and the Table Mountain Facility tropospheric ozone lidar show that MLS data are biased high by similar to 30% at 215 hPa, consistent with that indicated by the ozonesonde data. We obtain better global average agreement between MLS and ozonesonde partial column values down to 215 hPa, although the average MLS values at low to middle latitudes are higher than the ozonesonde values by up to a few percent. MLS v2.2 ozone data agree better than the MLS v1.5 data with ozonesonde and lidar measurements. MLS tropical data show the wave one longitudinal pattern in the upper troposphere, with similarities to the average distribution from ozonesondes. High upper tropospheric ozone values are also observed by MLS in the tropical Pacific from June to November. C1 [Jiang, Y. B.; Froidevaux, L.; Lambert, A.; Livesey, N. J.; Read, W. G.; Waters, J. W.; Fuller, R. A.; Daffer, W. H.; Drouin, B. J.; Cofield, R. E.; Cuddy, D. T.; Jarnot, R. F.; Knosp, B. W.; Perun, V. S.; Schwartz, M. J.; Snyder, W. V.; Stek, P. C.; Thurstans, R. P.; Wagner, P. A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Bojkov, B.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Leblanc, T.; McDermid, I. S.] CALTECH, Jet Prop Lab, Wrightwood, CA 92397 USA. [Godin-Beekmann, S.] Univ Paris 06, CNRS, Inst Pierre Simon Laplace, Serv Aeron, F-75252 Paris, France. [Filipiak, M. J.; Harwood, R. S.] Univ Edinburgh, Inst Atmospher & Environm Sci, Edinburgh EH9 3JZ, Midlothian, Scotland. [Allaart, M.; Kelder, H.] Royal Netherlands Meteorol Inst, NL-3730 AE De Bilt, Netherlands. [Andersen, S. B.] Danish Meteorol Inst, DK-20100 Copenhagen, Denmark. [Bodeker, G.] Natl Inst Water & Atmospher Res, Lauder, New Zealand. [Calpini, B.; Stubi, R.; Viatte, P.] MeteoSwiss, Aerol Stn Payerne, CH-1530 Payerne, Switzerland. [Claude, H.] German Weather Serv, Meteorol Observ Hohenpeissenberg, D-82383 Hohenpeissenberg, Germany. [Coetzee, G.] S African Weather Serv, ZA-0062 Irene, South Africa. [Davies, J.; Tarasick, D.] Environm Canada, Downsview, ON M3H 5T4, Canada. [De Backer, H.] Royal Meteorol Inst Belgium, B-1180 Brussels, Belgium. [Dier, H.] German Weather Serv, Meteor Observ Lindenberg, D-15864 Lindenberg, Germany. [Fujiwara, M.] Hokkaido Univ, Grad Sch Environm Earth Sci, Sapporo, Hokkaido 0600810, Japan. [Johnson, B.; Oltmans, S.] NOAA, Earth Syst Res Lab, Global Monitoring Div, Boulder, CO 80305 USA. [Leme, N. P.] Inst Nacl Pesquisas Espaciais, Lab Ozonio, BR-12201970 Sao Paulo, Brazil. [Koenig-Langlo, G.] Alfred Wegener Inst Polar & Marine Res, D-27515 Bremerhaven, Germany. [Kyro, E.] Finnish Meteorol Inst, Arctic Res Ctr, FIN-99600 Sodankyla, Finland. [Laneve, G.] Univ Rome, Ctr Ric Progetto San Marco, I-00185 Rome, Italy. [Fook, L. S.] Malaysian Meteorol Serv, Selangor 46667, Malaysia. [Merrill, J.] Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. [Morris, G.] Valparaiso Univ, Dept Phys & Astron, Valparaiso, IN 46383 USA. [Newchurch, M.] Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35805 USA. [Parrondos, M. C.; Yela, M.] Natl Inst Aerosp Technol, E-28850 Madrid, Spain. [Posny, F.] Lab Atmosphere & Cyclones, F-97715 La Reunion, France. [Schmidlin, F.] NASA, Goddard Space Flight Ctr, Wallops Isl, VA 23337 USA. [Skrivankova, P.] Czech Hydrometeorol Inst, Prague 14306, Czech Republic. [Thompson, A.] Penn State Univ, Dept Meteorol, State Coll, PA 16802 USA. [Thouret, V.] CNRS, Lab Aerol, F-31400 Toulouse, France. [Vomel, H.] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. [von Der Gathen, P.] Alfred Wegener Inst, D-14473 Potsdam, Germany. [Zablocki, G.] Inst Meteorol & Water Management, PL-05120 Legionowo, Poland. RP Jiang, YB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ybj@mls.jpl.nasa.gov RI von der Gathen, Peter/B-8515-2009; Fujiwara, Masatomo/F-7852-2012; andersen, signe/C-4809-2013; Schwartz, Michael/F-5172-2016; Konig-Langlo, Gert/K-5048-2012; Yela, Margarita/J-7346-2016; Thompson, Anne /C-3649-2014 OI Laneve, Giovanni/0000-0001-6108-9764; Tarasick, David/0000-0001-9869-0692; von der Gathen, Peter/0000-0001-7409-1556; andersen, signe/0000-0002-8216-0141; Schwartz, Michael/0000-0001-6169-5094; Konig-Langlo, Gert/0000-0002-6100-4107; Yela, Margarita/0000-0003-3775-3156; Thompson, Anne /0000-0002-7829-0920 NR 33 TC 68 Z9 68 U1 0 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 15 PY 2007 VL 112 IS D24 AR D24S34 DI 10.1029/2007JD008776 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 241YN UT WOS:000251691800002 ER PT J AU Massie, S Gille, J Khosravi, R Lee, H Kinnison, D Francis, G Nardi, B Eden, T Craig, C Halvorson, C Coffey, M Packman, D Cavanaugh, C Craft, J Dean, V Ellis, D Barnett, J Hepplewhite, C Lambert, A Manney, G Strawa, A Legg, M AF Massie, Steven Gille, John Khosravi, Rashid Lee, Hyunah Kinnison, Douglas Francis, Gene Nardi, Bruno Eden, Thomas Craig, Cheryl Halvorson, Chris Coffey, Michael Packman, Daniel Cavanaugh, Charles Craft, James Dean, Vincil Ellis, David Barnett, John Hepplewhite, Christopher Lambert, Alyn Manney, Gloria Strawa, Anthony Legg, Marion TI High Resolution Dynamics Limb Sounder observations of polar stratospheric clouds and subvisible cirrus SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HALOGEN OCCULTATION EXPERIMENT; NORTHERN-HEMISPHERE WINTER; TROPICAL TROPOPAUSE; II OBSERVATIONS; POAM-III; SAGE-II; AEROSOL; VALIDATION; UARS; CLIMATOLOGY AB [1] The High Resolution Dynamics Limb Sounder (HIRDLS) cloud detection and cloud top determination algorithm is described and applied to 2005-2007 HIRDLS radiance profiles. Statistical averages of HIRDLS and correlative cloud data are highly correlated. The 1998-2005 Halogen Occultation Experiment (HALOE) and HIRDLS time averaged cloud top pressures have a correlation coefficient of 0.87 and 0.93 in the tropics and midlatitudes, respectively. Time series of the temperature T < 195 K hemispherical area, on the 450 K potential temperature surface, and the total number of polar stratospheric clouds observed by the HIRDLS experiment in January and February 2005 have a correlation coefficient of 0.92. HALOE and HIRDLS normalized distributions of cloud counts, expressed as a function of outgoing longwave radiation (OLR), have a correlation coefficient of 0.99. Tropical averages of 1998-2005 HALOE and HIRDLS cloud occurrence frequencies at 82 and 100 hPa are within 25% of each other, and the morphology of latitude-longitude contour maps of cloud frequency are similar. Colocated Stratospheric Aerosol and Gas Experiment (SAGE III) and HIRDLS cloud top pressure values in 2005 have a correlation coefficient of 0.85 when the distance between observations is less than 100 km and the time difference is less than 6 h. Correlations between colocated SAGE III and HIRDLS cloud top pressures improve as space and time differences decrease. C1 [Massie, Steven; Gille, John; Khosravi, Rashid; Lee, Hyunah; Kinnison, Douglas; Francis, Gene; Nardi, Bruno; Eden, Thomas; Craig, Cheryl; Halvorson, Chris; Coffey, Michael; Packman, Daniel; Cavanaugh, Charles] Natl Ctr Atmospher Res, Boulder, CO 80307 USA. [Craft, James; Dean, Vincil; Ellis, David] Univ Colorado, Ctr Limb Atmospher Sounding, Boulder, CO 80309 USA. [Barnett, John; Hepplewhite, Christopher] Univ Oxford, Dept Phys, Oxford OX1 3PU, England. [Lambert, Alyn; Manney, Gloria] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Manney, Gloria] New Mexico Inst Min & Technol, Socorro, NM 87801 USA. [Strawa, Anthony] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Legg, Marion] Bay Area Environm Res Inst, Sonoma, CA 95476 USA. RP Massie, S (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM massie@ucar.edu NR 33 TC 17 Z9 18 U1 2 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 15 PY 2007 VL 112 IS D24 AR D24S31 DI 10.1029/2007JD008788 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 241YN UT WOS:000251691800003 ER PT J AU Bian, H Chin, M Kawa, SR Duncan, B Arellano, A Kasibhatla, P AF Bian, H. Chin, M. Kawa, S. R. Duncan, B. Arellano, A. Kasibhatla, P. TI Sensitivity of global CO simulations to uncertainties in biomass burning sources SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ART. NO. 4100; CARBON-MONOXIDE; INTERANNUAL VARIABILITY; TROPOSPHERIC CHEMISTRY; HYDROXYL RADICALS; OZONE POLLUTION; FIRE EMISSIONS; ALPHA-PINENE; MODEL; TRANSPORT AB One of the largest uncertainties for the modeling of tropospheric carbon monoxide ( CO) concentration is the timing, location, and magnitude of biomass burning emissions. We investigate the sensitivity of simulated CO in the Unified Chemistry Transport Model ( UCTM) to several biomass burning emissions, including four bottom-up and two top-down inventories. We compare the sensitivity experiments with observations from MOPITT, surface and airborne NOAA Global Monitoring Division network data, and the TRACE-P field campaign. The variation of the global annual emissions of these six biomass burning inventories is within 30%; however, their regional variations are often much higher ( factor of 2 - 5). These uncertainties translate to about 6% variation in the global simulated CO but more than a 100% variation in some regions. The annual mean CO variation is greater in the Southern Hemisphere (> 12%) than in the Northern Hemisphere (< 5%), largely because biomass burning is a higher percentage of the total source in the Southern Hemisphere. Comparisons with CO observations indicate that each model inventory has its strengths and shortcomings, and these regional variations are examined. Overall the model CO concentrations are within the observed range of variability at most stations including Ascension Island, which is strongly influenced by fire emissions. In addition, we discuss the systematic biases that exist in the inventories developed by the similar methodologies and original satellite data. C1 [Bian, H.; Duncan, B.] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. [Bian, H.; Chin, M.; Kawa, S. R.; Duncan, B.] NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. [Kasibhatla, P.] Duke Univ, Nicholas Sch Environm & Earth Sci, Durham, NC 27708 USA. [Arellano, A.] Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Bian, H (reprint author), Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. EM bian@rondo.gsfc.nasa.gov RI Arellano, Avelino, Jr./F-5674-2010; Kasibhatla, Prasad/A-2574-2010; Duncan, Bryan/A-5962-2011; Kawa, Stephan/E-9040-2012; Chin, Mian/J-8354-2012; OI Kasibhatla, Prasad/0000-0003-3562-3737 NR 76 TC 31 Z9 32 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 14 PY 2007 VL 112 IS D23 AR D23308 DI 10.1029/2006JD008376 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 241YG UT WOS:000251691100001 ER PT J AU Varnai, T Cahalan, RF AF Varnai, Tamas Cahalan, Robert F. TI Potential for airborne offbeam lidar measurements of snow and sea ice thickness SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ARCTIC SEA; RADIATIVE-TRANSFER; SOUTHERN-OCEAN; DEPTH; LIGHT; VARIABILITY; SCATTERING; COVER; SOOT; MICROSTRUCTURE AB [1] This article discusses the capabilities and limitations of a new approach to airborne measurements of snow and sea ice thickness. Such measurements can help better understand snow and sea ice processes and can also contribute to the validation of satellite measurements. The approach discussed here determines physical snow and sea ice thickness by observing the horizontal spread of lidar pulses: The bright halo observed around an illuminated spot extends farther out in thicker layers because photons can travel longer without escaping through the bottom. Since earlier studies suggested the possibility of such sea ice retrievals, this article presents a theoretical analysis of additional uncertainties that arise in airborne observations of snow and sea ice. Snow and sea ice retrievals pose somewhat different challenges because while sea ice is usually much thicker, snow contains a much higher concentration of scatterers. As a result, sea ice halos are larger, but snow halos are brighter. The results indicate that airborne sea ice retrievals are possible at night and that snow retrievals are possible during both night and day. For snow thicknesses less than about 50 cm, observational issues, such as calibration uncertainty, can cause retrieval uncertainties on the order of 10% in 1-km-resolution retrievals. For moderate snow and sea ice thicknesses (< 30 cm and 3 m, respectively), these issues cause similar (similar to 10%) uncertainties in sea ice thickness retrievals as well. These results indicate that offbeam lidars have the potential to become an important component of future snow and sea ice observing systems. C1 [Cahalan, Robert F.] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. [Varnai, Tamas] Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. RP Varnai, T (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Suite 320,5523 Res Pk Dr, Baltimore, MD 21228 USA. EM tamas.varnai@nasa.gov; robert.f.cahalan@nasa.gov RI Cahalan, Robert/E-3462-2012 OI Cahalan, Robert/0000-0001-9724-1270 NR 43 TC 6 Z9 6 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 14 PY 2007 VL 112 IS C12 AR C12S90 DI 10.1029/2007JC004091 PG 11 WC Oceanography SC Oceanography GA 241YW UT WOS:000251692700002 ER PT J AU Chylek, P Lohmann, U Dubey, M Mishchenko, M Kahn, R Ohmura, A AF Chylek, Petr Lohmann, Ulrike Dubey, Manvendra Mishchenko, Michael Kahn, Ralph Ohmura, Atsumu TI Limits on climate sensitivity derived from recent satellite and surface observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GLOBAL RADIATION BUDGET; THERMAL EQUILIBRIUM; AEROSOL; CONSTRAINTS; ATMOSPHERE; TREND; MODEL AB An analysis of satellite and surface measurements of aerosol optical depth suggests that global average of aerosol optical depth has been recently decreasing at the rate of around 0.0014/a. This decrease is nonuniform with the fastest decrease observed over the United States and Europe. The observed rate of decreasing aerosol optical depth produces the top of the atmosphere radiative forcing that is comparable to forcing due to the current rate of increasing atmospheric concentration of carbon dioxide and other greenhouse gases. Consequently, both increasing atmospheric concentration of greenhouse gases and decreasing loading of atmospheric aerosols are major contributors to the top-of-atmosphere radiative forcing. We find that the climate sensitivity is reduced by at least a factor of 2 when direct and indirect effects of decreasing aerosols are included, compared to the case where the radiative forcing is ascribed only to increases in atmospheric concentrations of carbon dioxide. We find the empirical climate sensitivity to be between 0.29 and 0.48 K/Wm(-2) when aerosol direct and indirect radiative forcing is included. C1 [Chylek, Petr; Dubey, Manvendra] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. [Lohmann, Ulrike; Ohmura, Atsumu] ETH, Inst Atmospher & Climate Sci, CH-8092 Zurich, Switzerland. [Mishchenko, Michael] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Kahn, Ralph] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chylek, P (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM chylek@lanl.gov RI Dubey, Manvendra/E-3949-2010; Kahn, Ralph/D-5371-2012; Mishchenko, Michael/D-4426-2012; Lohmann, Ulrike/B-6153-2009 OI Dubey, Manvendra/0000-0002-3492-790X; Kahn, Ralph/0000-0002-5234-6359; Lohmann, Ulrike/0000-0001-8885-3785 NR 35 TC 29 Z9 29 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 13 PY 2007 VL 112 IS D24 AR D24S04 DI 10.1029/2007JD008740 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 241YL UT WOS:000251691600001 ER PT J AU Muller, R Tilmes, S Grooss, JU Engel, A Oelhaf, H Wetzel, G Huret, N Pirre, M Catoire, V Toon, G Nakajima, H AF Mueller, Rolf Tilmes, Simone Grooss, Jens-Uwe Engel, Andreas Oelhaf, Hermann Wetzel, Gerald Huret, Nathalie Pirre, Michel Catoire, Valery Toon, Geoff Nakajima, Hideaki TI Impact of mesospheric intrusions on ozone-tracer relations in the stratospheric polar vortex SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ARCTIC WINTER 2002/2003; HALOGEN OCCULTATION EXPERIMENT; CHLORINE ACTIVATION; DENITRIFICATION; CLIMATOLOGY; SATELLITE; DEPLETION; VORTICES; BALLOON; MODEL AB [1] Ozone-tracer relations are used to quantify chemical ozone loss in the polar vortices. The underlying assumptions for the application of this technique were extensively discussed in recent years. However, the impact intrusions of mesospheric air into the polar stratosphere have on estimates of chemical ozone loss based on the ozone-tracer technique has not hitherto been studied. Here, we revisit observations of an intrusion of mesospheric air down to altitudes of similar to 25 km (similar to 600 K potential temperature) in the Arctic vortex in 2003. The mesospheric intrusion was identified in three balloon profiles in January and March 2003 as a strong enhancement in CO. In contrast, NOy was not enhanced in the mesospheric air relative to surrounding air masses as shown by the measurement in late March 2003. The measurements influenced by mesospheric air show ozone mixing ratios ranging between 3.6 and 5.6 ppm, which are clearly greater than those found in the "early vortex" reference relation employed to deduce chemical ozone loss. Thus the impact of intrusions of mesospheric air into the polar vortex on chemical ozone loss estimates based on ozone-tracer relations are likely small; the correlations cannot be affected in a way that would lead to an overestimate of ozone depletion. Therefore ozone-tracer relations may be used for deducing chemical ozone loss in Arctic winter 2002-2003. Here we use ILAS-II satellite measurements to deduce an average chemical ozone loss in the vortex core for the partial column 380-550 K of 37 +/- 11 Dobson units in March and of 50 +/- 10 Dobson units in April 2003. C1 [Mueller, Rolf; Grooss, Jens-Uwe] Forschungszentrum Julich, Inst Stratospher Chem, D-52425 Julich, Germany. [Toon, Geoff] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Tilmes, Simone] Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. [Oelhaf, Hermann; Wetzel, Gerald] Forschungszentrum Karlsruhe, IMK ASF, D-76021 Karlsruhe, Germany. [Nakajima, Hideaki] NIES, Div Atmospher Environm, Tsukuba, Ibaraki 3058506, Japan. [Engel, Andreas] Goethe Univ Frankfurt, Inst Atmosphar & Umwelt, D-60325 Frankfurt, Germany. [Huret, Nathalie; Pirre, Michel; Catoire, Valery] Univ Orleans, CNRS, UMR 6115, Lab Phys & Chim Enviornn, F-45071 Orleans 2, France. RP Muller, R (reprint author), Forschungszentrum Julich, Inst Stratospher Chem, ICG 1, D-52425 Julich, Germany. EM ro.mueller@fz-juelich.de RI Muller, Rolf/A-6669-2013; Wetzel, Gerald/A-7065-2013; GrooSS, Jens-Uwe/A-7315-2013; Oelhaf, Hermann/A-7895-2013; Catoire, Valery/E-9662-2015; Engel, Andreas/E-3100-2014 OI Muller, Rolf/0000-0002-5024-9977; GrooSS, Jens-Uwe/0000-0002-9485-866X; Catoire, Valery/0000-0001-8126-3096; Engel, Andreas/0000-0003-0557-3935 NR 53 TC 14 Z9 14 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 13 PY 2007 VL 112 IS D23 AR D23307 DI 10.1029/2006JD008315 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 241YF UT WOS:000251691000003 ER PT J AU Vidali, G Pirronello, V Li, L Roser, J Manico, G Congiu, E Mehl, H Lederhendler, A Perets, HB Brucato, JR Biham, O AF Vidali, G. Pirronello, V. Li, L. Roser, J. Manico, G. Congiu, E. Mehl, H. Lederhendler, A. Perets, H. B. Brucato, J. R. Biham, O. TI Analysis of molecular hydrogen formation on low-temperature surfaces in temperature programmed desorption experiments SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MASTER EQUATION APPROACH; GAS-GRAIN CHEMISTRY; AMORPHOUS WATER ICE; INTERSTELLAR GRAINS; CHEMICAL-REACTIONS; ATOMIC-HYDROGEN; H-2 FORMATION; ASTROPHYSICAL INTEREST; MOMENT EQUATIONS; RECOMBINATION AB The study of the formation of molecular hydrogen on low-temperature surfaces is of interest both because it enables the exploration of elementary steps in the heterogeneous catalysis of a simple molecule and because of its applications in astrochemistry. Here, we report results of experiments of molecular hydrogen formation on amorphous silicate surfaces using temperature-programmed desorption (TPD). In these experiments, beams of H and D atoms are irradiated on the surface of an amorphous silicate sample. The desorption rate of HD molecules is monitored using a mass spectrometer during a subsequent TPD run. The results are analyzed using rate equations, and the energy barriers of the processes leading to molecular hydrogen formation are obtained from the TPD data. We show that a model based on a single isotope provides the correct results for the activation energies for diffusion and desorption of H atoms. These results are used in order to evaluate the formation rate of H-2 on dust grains under the actual conditions present in interstellar clouds. It is found that, under typical conditions in diffuse interstellar clouds, amorphous silicate grains are efficient catalysts of H-2 formation when the grain temperatures are between 9 and 14 K. This temperature window is within the typical range of grain temperatures in diffuse clouds. It is thus concluded that amorphous silicates are good candidates to be efficient catalysts of H-2 formation in diffuse clouds. C1 Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Syracuse Univ, Dept Phys, Syracuse, NY 13244 USA. Univ Catania, DMFCI, I-95125 Catania, Sicily, Italy. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Weizmann Inst Sci, Fac Phys, IL-76100 Rehovot, Israel. INAF, Osservatorio Astron Capodimonte, Naples, Italy. RP Biham, O (reprint author), Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. RI Perets, Hagai/K-9605-2015; OI Perets, Hagai/0000-0002-5004-199X; Brucato, John Robert/0000-0002-4738-5521 NR 64 TC 22 Z9 22 U1 3 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD DEC 13 PY 2007 VL 111 IS 49 BP 12611 EP 12619 DI 10.1021/jp0760657 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 239KU UT WOS:000251518000058 PM 17988107 ER PT J AU Arumugam, PU Chen, H Cassell, AM Li, J AF Arumugam, Prabhu U. Chen, Hua Cassell, Alan M. Li, Jun TI Dielectrophoretic trapping of single bacteria at carbon nanofiber nanoelectrode arrays SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ESCHERICHIA-COLI; CELL MANIPULATION; DNA; CHIP AB We present an ac dielectrophoretic (DEP) technique for single-cell trapping using embedded carbon nanofiber (CNF) nanoelectrode arrays (NEAs). NEAs fabricated by inlaying vertically aligned carbon nanofibers in SiO2 matrix are applied as "points-and-lid" DEP devices in aqueous solution. The miniaturization of the electrode size provides a highly focused electrical field with the gradient enhanced by orders of magnitude. This generates extremely large positive DEP forces near the electrode surface and traps small bioparticles against strong hydrodynamic forces. This technology promises new capabilities to perform novel cell biology experiments at the nanoscale. We anticipate that the bottom-up approach of such nano-DEP devices allows the integration of millions of nanolectrodes deterministically in lab-on-a-chip devices and will be generally useful for manipulating submicron particles. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Santa Cruz, Univ Affiliated Res Ctr, Moffett Field, CA 94035 USA. ELORET, Moffett Field, CA 94035 USA. RP Li, J (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM paramugan@arc.nasa.gov; junli@ksu.edu RI Li, Jun/H-7771-2013 OI Li, Jun/0000-0002-3689-8946 FU NINDS NIH HHS [R21 NS047721] NR 23 TC 16 Z9 16 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD DEC 13 PY 2007 VL 111 IS 49 BP 12772 EP 12777 DI 10.1021/jp076346e PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 239KU UT WOS:000251518000079 PM 17999481 ER PT J AU Gintert, MJ Jana, SC Miller, SG AF Gintert, Michael J. Jana, Sadhan C. Miller, Sandi G. TI An optimum organic treatment of nanoclay for PMR-15 nanocomposites SO POLYMER LA English DT Article DE nanocomposites; layered silicate clay; organic treatment ID EPOXY-CLAY NANOCOMPOSITES; THERMOPLASTIC POLYURETHANE NANOCOMPOSITES; POLYMER/LAYERED SILICATE NANOCOMPOSITES; ALKYL AMMONIUM-IONS; MECHANICAL-PROPERTIES; POLYMER NANOCOMPOSITES; THERMAL-STABILITY; OXIDATIVE-DEGRADATION; EXFOLIATION; POLYIMIDE AB The present study examined ion exchange of layered silicate clay by ammonium ions and investigated thermal dissociation of ammonium ions and the presence of nadic endgroups in ammonium ions on the potential of clay exfoliation in nanocomposites of PMR-15 (an oligomer with molecular weight 1500). A novel method of organoclay exfoliation was used. It involved organoclay intercalation by lower molecular weight PMR-5 oligomer, dispersion of PMR-5/clay mixture in higher molecular weight PMR-15 resin, and curing of the resultant mixtures at approximately 315 degrees C. The PMR-5 resin residing inside the clay galleries underwent crosslinking during curing and produced higher elastic forces to facilitate clay platelets exfoliation against a slower rising viscous force in the matrix PMR-15 resin. It was found that the ammonium ions with nadic endgroups participated in intra-gallery PMR-5 resin crosslinking reactions and promoted better exfoliation compared to non-reactive arnmonium ions. Improvements in thermal and mechanical properties were also observed. (C) 2007 Elsevier Ltd. All rights reserved. C1 [Gintert, Michael J.; Jana, Sadhan C.] Univ Akron, Dept Polymer Engn, Akron, OH 44325 USA. [Miller, Sandi G.] NASA, Glenn Res Ctr, Polymer Branch, Cleveland, OH 44135 USA. RP Jana, SC (reprint author), Univ Akron, Dept Polymer Engn, Akron, OH 44325 USA. EM janas@uakron.edu OI Jana, Sadhan/0000-0001-8962-380X NR 58 TC 5 Z9 5 U1 1 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD DEC 13 PY 2007 VL 48 IS 26 BP 7573 EP 7581 DI 10.1016/j.polymer.2007.11.004 PG 9 WC Polymer Science SC Polymer Science GA 250GW UT WOS:000252289000018 ER PT J AU Chaudhry, Z Martins, JV Li, ZQ Tsay, SC Chen, HB Wang, P Wen, TX Li, C Dickerson, RR AF Chaudhry, Zahra Martins, J. Vanderlei Li, Zhanqing Tsay, Si-Chee Chen, Hongbin Wang, Pucai Wen, Tianxue Li, Can Dickerson, Russell R. TI In situ measurements of aerosol mass concentration and radiative properties in Xianghe, southeast of Beijing SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID BLACK CARBON CONTENT; LIGHT-ABSORPTION; WAVELENGTH DEPENDENCE; CHEMICAL-COMPOSITION; PARTICLES; COEFFICIENT; SIZE; CALIBRATION; PERIOD; BRAZIL AB [1] As a part of the EAST-AIRE study, Nuclepore filters were collected in two size ranges (coarse, 2.5 mu m < d < 10 mu m, and fine, d < 2.5 mu m) from January to May 2005 in Xianghe, about 70 km southeast of Beijing, and analyzed for aerosol mass concentration, spectral absorption efficiency and absorption coefficient. Twelve-hour aerosol mass concentration measurements showed an average concentration of 120 mu g/m(3) in the coarse mode and an average concentration of 25 mu g/m(3) in the fine mode. To determine how representative ground-based measurements are of the total column, the mass concentration data was compared with AERONET AOT at 500 nm and AERONET size distribution data. The vertical distribution of the aerosols were studied with a micropulse lidar and in the cases where the vertical column was found to be fairly homogenous, the comparisons of the filter results with AERONET agreed favorably, while in the cases of inhomogeneity, the comparisons have larger disagreement. For fine mode aerosols, the average spectral absorption efficiency equates well to a lambda(-1) model, while the coarse mode shows a much flatter spectral dependence, consistent with large particle models. The coarse mode absorption efficiency was compatible with that of the fine mode in the NIR region, indicating the much stronger absorption of the coarse mode due to its composition and sizable mass. Single scattering albedo results are presented from a combination between absorption coefficients derived from the filter measurements, from a PSAP and from a three-wavelength Nephelometer. C1 [Chaudhry, Zahra; Li, Zhanqing; Li, Can; Dickerson, Russell R.] Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, Dept Atmospher & Ocean, College Pk, MD 20742 USA. [Martins, J. Vanderlei] Univ Maryland, Univ Maryland Baltimore Cty, Joint Ctr Earth Syst & Technol, Dept Phys, Baltimore, MD USA. [Martins, J. Vanderlei; Tsay, Si-Chee] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Li, Zhanqing] Chinese Acad Sci, Inst Atmospher Phys, Beijing, Peoples R China. [Chen, Hongbin; Wang, Pucai; Wen, Tianxue] Chinese Acad Sci, Inst Atmospher Phys, Beijing, Peoples R China. RP Chaudhry, Z (reprint author), Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, Dept Atmospher & Ocean, College Pk, MD 20742 USA. RI Li, Can/F-6867-2011; Li, Zhanqing/F-4424-2010; Tsay, Si-Chee/J-1147-2014; Dickerson, Russell/F-2857-2010 OI Li, Zhanqing/0000-0001-6737-382X; Dickerson, Russell/0000-0003-0206-3083 NR 36 TC 20 Z9 20 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 12 PY 2007 VL 112 IS D23 AR D23S90 DI 10.1029/2007JD009055 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 241YE UT WOS:000251690900004 ER PT J AU Nedoluha, GE Gomez, RM Hicks, BC Bevilacqua, RM Russell, JM Connor, BJ Lambert, A AF Nedoluha, Gerald E. Gomez, R. Michael Hicks, Brian C. Bevilacqua, Richard M. Russell, James M., III Connor, Brian J. Lambert, Alyn TI A comparison of middle atmospheric water vapor as measured by WVMS, EOS-MLS, and HALOE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MILLIMETER-WAVE SPECTROMETER; MICROWAVE LIMB SOUNDER; OCCULTATION EXPERIMENT; VALIDATION; RETRIEVAL AB We compare middle atmospheric water vapor measurements from the Halogen Occultation Experiment (HALOE), Water Vapor Mm-wave Spectrometer (WVMS), and Earth Observing System (EOS) Microwave Limb Sounder (MLS) instruments from 40 to 70 km. The ground-based WVMS measurements shown here were taken at Network for the Detection of Atmospheric Composition Change (NDACC) sites at Mauna Loa, Hawaii (19.5 degrees N, 204.4 degrees E), and Lauder, New Zealand (45.0 degrees S, 169.7 degrees E). A comparison of measurements where HALOE, MLS, and WVMS are all available shows that the average HALOE water vapor retrievals are lower than those from MLS at all altitudes from 40 to 70 km and lower than the WVMS retrievals everywhere except above 64 km at Lauder. The average difference between all coincident WVMS and MLS water vapor profiles is within 0.2 ppmv over almost the entire 40-70 km altitude range, both at Lauder and Mauna Loa. The standard deviation of the difference between weekly WVMS retrievals and coincident MLS retrievals is similar to 0.2 ppmv at Mauna Loa and similar to 0.3-0.4 ppmv at Lauder. The interannual correlation between water vapor observed by MLS and WVMS is slightly improved by the use of MLS temperature measurements in the WVMS retrievals. The MLS and WVMS profiles at Mauna Loa show particularly good interannual agreement, including a clear QBO signature. C1 [Nedoluha, Gerald E.; Gomez, R. Michael; Hicks, Brian C.; Bevilacqua, Richard M.] USN, Res Lab, Washington, DC 20375 USA. [Connor, Brian J.] Natl Inst Water & Atmospher Res, Lauder, New Zealand. [Lambert, Alyn] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Russell, James M., III] Hampton Univ, Dept Phys, Hampton, VA 23668 USA. RP Nedoluha, GE (reprint author), USN, Res Lab, Washington, DC 20375 USA. EM nedoluha@nrl.navy.mil NR 17 TC 20 Z9 20 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 12 PY 2007 VL 112 IS D24 AR D24S39 DI 10.1029/0007JD008757 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 241YJ UT WOS:000251691400001 ER PT J AU Cooper, OR Trainer, M Thompson, AM Oltmans, SJ Tarasick, DW Witte, JC Stohl, A Eckhardt, S Lelieveld, J Newchurch, MJ Johnson, BJ Portmann, RW Kalnajs, L Dubey, MK Leblanc, T McDermid, IS Forbes, G Wolfe, D Carey-Smith, T Morris, GA Lefer, B Rappengluck, B Joseph, E Schmidlin, F Meagher, J Fehsenfeld, FC Keating, TJ Van Curen, RA Minschwaner, K AF Cooper, O. R. Trainer, M. Thompson, A. M. Oltmans, S. J. Tarasick, D. W. Witte, J. C. Stohl, A. Eckhardt, S. Lelieveld, J. Newchurch, M. J. Johnson, B. J. Portmann, R. W. Kalnajs, L. Dubey, M. K. Leblanc, T. McDermid, I. S. Forbes, G. Wolfe, D. Carey-Smith, T. Morris, G. A. Lefer, B. Rappengluck, B. Joseph, E. Schmidlin, F. Meagher, J. Fehsenfeld, F. C. Keating, T. J. Van Curen, R. A. Minschwaner, K. TI Evidence for a recurring eastern North America upper tropospheric ozone maximum during summer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PARTICLE DISPERSION MODEL; STRATOSPHERIC OZONE; ART.; CLIMATE; TRANSPORT; ENHANCEMENT; POLLUTION; FLEXPART; SURFACE; TRENDS AB Daily ozonesondes were launched from 14 North American sites during August 2006, providing the best set of free tropospheric ozone measurements ever gathered across the continent in a single season. The data reveal a distinct upper tropospheric ozone maximum above eastern North America and centered over the southeastern USA. Recurring each year, the location and strength of the ozone maximum is influenced by the summertime upper tropospheric anticyclone that traps convectively lofted ozone, ozone precursors and lightning NOx above the southeastern USA. The North American summer monsoon that flows northward along the Rocky Mountains is embedded within the western side of the anticyclone and also marks the westernmost extent of the ozone maximum. Removing the influence from stratospheric intrusions, median ozone mixing ratios (78 ppbv) in the upper troposphere (> 6 km) above Alabama, near the center of the anticyclone, were nearly twice the level above the U. S. west coast. Simulations by an atmospheric chemistry general circulation model indicate lightning NOx emissions led to the production of 25-30 ppbv of ozone at 250 hPa above the southern United States during the study period. On the regional scale the ozone enhancement above the southeastern United States produced a positive all-sky adjusted radiative forcing up to 0.50 W m(-2). C1 [Cooper, O. R.; Trainer, M.; Oltmans, S. J.; Johnson, B. J.; Portmann, R. W.; Wolfe, D.; Meagher, J.; Fehsenfeld, F. C.] NOAA, Earth Syst Res Lab, Boulder, CO 80305 USA. [Cooper, O. R.] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. [Thompson, A. M.] Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. [Tarasick, D. W.] Environm Canada, Meteorol Serv Canada, Expt Studies Res Div, Downsview, ON M3H 5T4, Canada. [Witte, J. C.] NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. [Stohl, A.; Eckhardt, S.] Norwegian Inst Air Res, N-2027 Kjeller, Norway. [Lelieveld, J.] Max Planck Inst Chem, D-55128 Mainz, Germany. [Newchurch, M. J.] Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35806 USA. [Kalnajs, L.] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. [Dubey, M. K.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. [Leblanc, T.; McDermid, I. S.] CALTECH, Jet Propuls Lab, Table Mt Facil, Wrightwood, CA 92397 USA. [Forbes, G.] Meteorol Serv Canada, Dartmouth, NS B2Y 2N6, Canada. [Forbes, G.] Meteorol Serv Canada, Sable Island, NS, Canada. [Morris, G. A.] Valparaiso Univ, Dept Phys & Astron, Valparaiso, IN 46383 USA. [Lefer, B.; Rappengluck, B.] Univ Houston, Dept Geosci, Houston, TX 77204 USA. [Joseph, E.] Howard Univ, Dept Phys & Astron, Washington, DC 20059 USA. [Schmidlin, F.] NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. [Keating, T. J.] US EPA, Off Air & Radiat, Washington, DC 20460 USA. [Van Curen, R. A.] Calif Air Resources Board, Div Res, Atmospher Proc Res Sect, Sacramento, CA 95812 USA. [Minschwaner, K.] New Mexico Inst Min & Technol, Dept Phys, Socorro, NM 87801 USA. RP Cooper, OR (reprint author), NOAA, Earth Syst Res Lab, Boulder, CO 80305 USA. EM owen.r.cooper@noaa.gov RI Stohl, Andreas/A-7535-2008; Portmann, Robert/C-4903-2009; Dubey, Manvendra/E-3949-2010; Cooper, Owen/H-4875-2013; Trainer, Michael/H-5168-2013; Fehsenfeld, Frederick/I-4876-2013; Eckhardt, Sabine/I-4001-2012; Lelieveld, Johannes/A-1986-2013; Thompson, Anne /C-3649-2014; Manager, CSD Publications/B-2789-2015 OI Stohl, Andreas/0000-0002-2524-5755; Portmann, Robert/0000-0002-0279-6087; Dubey, Manvendra/0000-0002-3492-790X; Tarasick, David/0000-0001-9869-0692; Eckhardt, Sabine/0000-0001-6958-5375; Thompson, Anne /0000-0002-7829-0920; NR 40 TC 51 Z9 52 U1 3 U2 23 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 11 PY 2007 VL 112 IS D23 AR D23304 DI 10.1029/2007JD008710 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 241YD UT WOS:000251690800002 ER PT J AU Sgro, C Atwood, WB Baldini, L Barbiellini, G Bellazzini, R Belli, F Bonamente, E Borden, T Bregeon, J Brez, A Brigida, M Caliandro, GA Cecchi, C Cohen-Tanugi, J De Angelis, A Drell, P Favuzzi, C Fukazawa, Y Fusco, P Gargano, F Germani, S Giglietto, N Giordano, F Himel, T Hirayama, M Johnson, RP Katagiri, H Kataoka, J Kawai, N Kroeger, W Kuss, M Latronico, L Longo, F Loparco, F Lubrano, P Massai, MM Mazziotta, MN Minuti, M Mizuno, T Morselli, A Nelson, D Nordby, M Ohsugi, T Omodei, N Ozaki, M Pepe, M Raino, S Rando, R Razzano, M Rich, D Sadrozinski, HFW Scolieri, G Spandre, G Spinelli, P Sugizaki, M Tajima, H Takahashi, H Takahashi, T Yoshida, S Young, C Ziegler, M AF Sgro, C. Atwood, W. B. Baldini, L. Barbiellini, G. Bellazzini, R. Belli, F. Bonamente, E. Borden, T. Bregeon, J. Brez, A. Brigida, M. Caliandro, G. A. Cecchi, C. Cohen-Tanugi, J. De Angelis, A. Drell, P. Favuzzi, C. Fukazawa, Y. Fusco, P. Gargano, F. Germani, S. Giglietto, N. Giordano, F. Himel, T. Hirayama, M. Johnson, R. P. Katagiri, H. Kataoka, J. Kawai, N. Kroeger, W. Kuss, M. Latronico, L. Longo, F. Loparco, F. Lubrano, P. Massai, M. M. Mazziotta, M. N. Minuti, M. Mizuno, T. Morselli, A. Nelson, D. Nordby, M. Ohsugi, T. Omodei, N. Ozaki, M. Pepe, M. Raino, S. Rando, R. Razzano, M. Rich, D. Sadrozinski, H. F. -W. Scolieri, G. Spandre, G. Spinelli, P. Sugizaki, M. Tajima, H. Takahashi, H. Takahashi, T. Yoshida, S. Young, C. Ziegler, M. TI Construction, test and calibration of the GLAST silicon tracker SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6th International Conference on Radiation Effects on Semiconductor Materials, Detectors, and Devices CY OCT 10-13, 2006 CL Florence, ITALY SP Univ Florence, Inst Nazionale Fisica Scienza DE gamma-ray; silicon; tracker; calibration; beam test ID AREA SPACE TELESCOPE; READOUT ELECTRONICS AB The Gamma-ray Large Area Space Telescope represents a great advance in space application of silicon detectors. With a surface of 80 m(2) and about 1 M readout channels it is the largest silicon tracker ever built for a space experiment. GLAST is an astro-particle mission that will study the mostly unexplored, high energy (20 MeV-300 GeV) spectrum coming from active sources or diffused in the Universe. The detector integration and test phase is complete. The full instrument underwent environmental testing and the spacecraft integration phase has just started: the launch is foreseen in late 2007. In the meanwhile the spare modules are being used for instrument calibration and performance verification employing the CERN accelerator complex. A Calibration Unit has been exposed to photon, electron and hadron beams from a few GeV up to 300 GeV. We report on the status of the instrument and on the calibration campaign. (C) 2007 Elsevier B.V. All rights reserved. C1 [Sgro, C.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Kuss, M.; Latronico, L.; Massai, M. M.; Minuti, M.; Omodei, N.; Razzano, M.; Spandre, G.] Univ Pisa, Ist Nazl Fis Nucl, I-56127 Pisa, Italy. [Sgro, C.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Kuss, M.; Latronico, L.; Massai, M. M.; Mazziotta, M. N.; Minuti, M.; Ozaki, M.; Spandre, G.] Univ Pisa, Dipartimento Fis, I-56127 Pisa, Italy. [Atwood, W. B.; Johnson, R. P.; Sadrozinski, H. F. -W.; Ziegler, M.] Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA. [Barbiellini, G.; De Angelis, A.; Longo, F.] Ist Nazl Fis Nucl, Sez Trieste, I-34012 Trieste, Italy. [Belli, F.; Morselli, A.] Ist Nazl Fis Nucl, Sez Roma Vergata, I-00133 Rome, Italy. [Borden, T.; Cohen-Tanugi, J.; Drell, P.; Fukazawa, Y.; Kroeger, W.; Nelson, D.; Nordby, M.; Rich, D.; Sugizaki, M.; Tajima, H.; Young, C.] SLAC, Menlo Pk, CA 94025 USA. [Brigida, M.; Caliandro, G. A.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Katagiri, H.; Mazziotta, M. N.; Spinelli, P.] Univ Bari, Ist Nazl Fis Nucl, I-70126 Bari, Italy. [Brigida, M.; Caliandro, G. A.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Katagiri, H.; Mazziotta, M. N.; Spinelli, P.] Univ Bari, Dipartimento Fis, I-70126 Bari, Italy. [Bonamente, E.; Cecchi, C.; Germani, S.; Lubrano, P.; Pepe, M.; Scolieri, G.] Univ Perugia, Ist Nazl Fis Nucl, I-06123 Perugia, Italy. [Bonamente, E.; Cecchi, C.; Germani, S.; Lubrano, P.; Pepe, M.; Scolieri, G.] Univ Perugia, Dipartimento Fis, I-06123 Perugia, Italy. [De Angelis, A.] Univ Udine, Dipartimento Fis, I-33100 Udine, Italy. [Fukazawa, Y.; Katagiri, H.; Mizuno, T.; Ohsugi, T.; Takahashi, H.; Yoshida, S.] Hiroshima Univ, Higashihiroshima 7398526, Japan. [Hirayama, M.] Univ Maryland, Joint Ctr Astrophys, Baltimore, MD 21250 USA. [Kataoka, J.; Kawai, N.] Tokyo Inst Technol, Tokyo 1528551, Japan. [Ozaki, M.; Takahashi, T.] Inst Space & Astronaut Sci ISAS JAXA, Sagamihara, Kanagawa 2298510, Japan. [Rando, R.] Univ Padua, Ist Nazl Fis Nucl, I-35131 Padua, Italy. [Rando, R.] Univ Padua, Dipartimento Fis, I-35131 Padua, Italy. [Sgro, C.] Scuola Normale Super Pisa, I-56126 Pisa, Italy. [Hirayama, M.] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. RP Sgro, C (reprint author), Univ Pisa, Ist Nazl Fis Nucl, Largo B Pontecorvo 3, I-56127 Pisa, Italy. EM carmelo.sgro@pi.infn.it RI Morselli, Aldo/G-6769-2011; Kuss, Michael/H-8959-2012; Baldini, Luca/E-5396-2012; lubrano, pasquale/F-7269-2012; giglietto, nicola/I-8951-2012; Ozaki, Masanobu/K-1165-2013; Rando, Riccardo/M-7179-2013; Loparco, Francesco/O-8847-2015; Gargano, Fabio/O-8934-2015; Mazziotta, Mario /O-8867-2015; Sgro, Carmelo/K-3395-2016; OI De Angelis, Alessandro/0000-0002-3288-2517; Omodei, Nicola/0000-0002-5448-7577; Baldini, Luca/0000-0002-9785-7726; Morselli, Aldo/0000-0002-7704-9553; lubrano, pasquale/0000-0003-0221-4806; giglietto, nicola/0000-0002-9021-2888; Loparco, Francesco/0000-0002-1173-5673; Gargano, Fabio/0000-0002-5055-6395; Mazziotta, Mario /0000-0001-9325-4672; Rando, Riccardo/0000-0001-6992-818X; Sgro', Carmelo/0000-0001-5676-6214; SPINELLI, Paolo/0000-0001-6688-8864 NR 6 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 11 PY 2007 VL 583 IS 1 SI SI BP 9 EP 13 DI 10.1016/j.nima.2007.08.224 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 244JB UT WOS:000251861100003 ER PT J AU Tubiello, FN Soussana, JF Howden, SM AF Tubiello, Francesco N. Soussana, Jean-Francois Howden, S. Mark TI Crop and pasture response to climate change SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE agriculture; impacts ID AIR CO2 ENRICHMENT; ELEVATED ATMOSPHERIC CO2; CARBON-DIOXIDE; CHANGE IMPACTS; GRASSLAND RESPONSES; DECIDUOUS FOREST; LAND-USE; INTEGRATED ASSESSMENT; WATER RELATIONS; N-DEPOSITION AB We review recent research of importance to understanding crop and pasture plant species response to climate change. Topics include plant response to elevated CO2 concentration, interactions with climate change variables and air pollutants, impacts of increased climate variability and frequency of extreme events, the role of weeds and pests, disease and animal health, issues in biodiversity, and vulnerability of soil carbon pools. We critically analyze the links between fundamental knowledge at the plant and plot level and the additional socio-economic variables that determine actual production and trade of food at regional to global scales. We conclude by making recommendations for current and future research needs, with a focus on continued and improved integration of experimental and modeling efforts. C1 [Tubiello, Francesco N.] Columbia Univ, Goddard Inst Space Studies, New York, NY 10025 USA. [Tubiello, Francesco N.] Int Inst Appl Syst Anal, A-2361 Laxenburg, Austria. [Soussana, Jean-Francois] Inst Natl Rech Agron, Unite Rech Agron 874, F-63100 Clermont Ferrand, France. [Howden, S. Mark] Commonwealth Sci & Ind Res Org Sustainable Ecosys, Canberra, ACT 2601, Australia. RP Tubiello, FN (reprint author), Columbia Univ, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM franci@giss.nasa.gov RI Howden, Stuart/C-1138-2008; Soussana, Jean-Francois/P-2094-2016; Soussana, Jean-Francois/E-2543-2012 OI Howden, Stuart/0000-0002-0386-9671; Soussana, Jean-Francois/0000-0002-1932-6583; NR 88 TC 275 Z9 296 U1 14 U2 164 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD DEC 11 PY 2007 VL 104 IS 50 BP 19686 EP 19690 DI 10.1073/pnas.0701728104 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 242UR UT WOS:000251752200009 PM 18077401 ER PT J AU Howden, SM Soussana, JF Tubiello, FN Chhetri, N Dunlop, M Meinke, H AF Howden, S. Mark Soussana, Jean-Francois Tubiello, Francesco N. Chhetri, Netra Dunlop, Michael Meinke, Holger TI Adapting agriculture to climate change SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE adaptation; greenhouse; cropping; grazing; forestry ID CHANGE IMPACTS; FOOD SECURITY; UNITED-STATES; ADAPTATION; SCENARIOS; CROP; VARIABILITY; POLICY; CO2; FERTILIZATION AB The strong trends in climate change already evident, the likelihood of further changes occurring, and the increasing scale of potential climate impacts give urgency to addressing agricultural adaptation more coherently. There are many potential adaptation options available for marginal change of existing agricultural systems, often variations of existing climate risk management. We show that implementation of these options is likely to have substantial benefits under moderate climate change for some cropping systems. However, there are limits to their effectiveness under more severe climate changes. Hence, more systemic changes in resource allocation need to be considered, such as targeted diversification of production systems and livelihoods. We argue that achieving increased adaptation action will necessitate integration of climate change-related issues with other risk factors, such as climate variability and market risk, and with other policy domains, such as sustainable development. Dealing with the many barriers to effective adaptation will require a comprehensive and dynamic policy approach covering a range of scales and issues, for example, from the understanding by farmers of change in risk profiles to the establishment of efficient markets that facilitate response strategies. Science, too, has to adapt. Multidisciplinary problems require multidisciplinary solutions, i.e., a focus on integrated rather than disciplinary science and a strengthening of the interface with decision makers. A crucial component of this approach is the implementation of adaptation assessment frameworks that are relevant, robust, and easily operated by all stakeholders, practitioners, policymakers, and scientists. C1 [Howden, S. Mark; Dunlop, Michael] Commonwealth Sci & Ind Res Org, Sustainable Ecosyst, Canberra, ACT 2601, Australia. [Soussana, Jean-Francois] INRA, UR874, F-63100 Clermont Ferrand, France. [Tubiello, Francesco N.] Columbia Univ, Goddard Inst Space Studies, New York, NY 10025 USA. [Tubiello, Francesco N.] Int Inst Appl Syst Anal, A-2361 Laxenburg, Austria. [Chhetri, Netra] Arizona State Univ, Consortium Sci Policy & Outcomes, Tempe, AZ 85287 USA. [Meinke, Holger] Wageningen Univ, Dept Plant Sci, NL-6700 AK Wageningen, Netherlands. RP Howden, SM (reprint author), Commonwealth Sci & Ind Res Org, Sustainable Ecosyst, GPO Box 284, Canberra, ACT 2601, Australia. EM mark.howden@csiro.au RI Howden, Stuart/C-1138-2008; Dunlop, Michael/D-5361-2011; Meinke, Holger/C-7215-2013; Soussana, Jean-Francois/P-2094-2016; Soussana, Jean-Francois/E-2543-2012 OI Howden, Stuart/0000-0002-0386-9671; Meinke, Holger/0000-0003-2657-3264; Soussana, Jean-Francois/0000-0002-1932-6583; NR 65 TC 483 Z9 500 U1 58 U2 347 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD DEC 11 PY 2007 VL 104 IS 50 BP 19691 EP 19696 DI 10.1073/pnas.0701890104 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 242UR UT WOS:000251752200010 PM 18077402 ER PT J AU Diner, DJ Davis, A Hancock, B Gutt, G Chipman, RA Cairns, B AF Diner, David J. Davis, Ab Hancock, Bruce Gutt, Gary Chipman, Russell A. Cairns, Brian TI Dual-photoelastic-modulator-based polarimetric imaging concept for aerosol remote sensing SO APPLIED OPTICS LA English DT Article ID SPECTRORADIOMETER MISR; PIEZOELASTIC MODULATOR; OPTICAL DEPTH; RETRIEVAL; OCEAN; MULTIANGLE; CALIBRATION; POLARIZATION; INTENSITY; DETECTOR AB A dual-photoelastic-modulator-(PEM-) based spectropolarimetric camera concept is presented as an approach for global aerosol monitoring from space. The most challenging performance objective is to measure degree of linear polarization (DOLP) with an uncertainty of less than 0.5% in multiple spectral bands, at moderately high spatial resolution, over a wide field of view, and for the duration of a multiyear mission. To achieve this, the tandem PEMs are operated as an electro-optic circular retardance modulator within a high-performance reflective imaging system. Operating the PEMs at slightly different resonant frequencies generates a beat signal that modulates the polarized component of the incident light at a much lower heterodyne frequency. The Stokes parameter ratio q = Q/I is obtained from measurements acquired from each pixel during a single frame, providing insensitivity to pixel responsivity drift and minimizing polarization artifacts that conventionally arise when this quantity is derived from differences in the signals from separate detectors. Similarly, u = U/I is obtained from a different pixel; q and u are then combined to form the DOLP. A detailed accuracy and tolerance analysis for this polarimeter is presented. (c) 2007 Optical Society of America. C1 [Diner, David J.; Davis, Ab; Hancock, Bruce; Gutt, Gary] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Chipman, Russell A.] Univ Arizona, Coll Opt Sci, Tucson, AZ 85721 USA. [Cairns, Brian] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Diner, DJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM David.J.Diner@jpl.nasa.gov OI Cairns, Brian/0000-0002-1980-1022 NR 42 TC 54 Z9 59 U1 4 U2 24 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD DEC 10 PY 2007 VL 46 IS 35 BP 8428 EP 8445 DI 10.1364/AO.46.008428 PG 18 WC Optics SC Optics GA 249LE UT WOS:000252229000006 PM 18071373 ER PT J AU Deo, RP Crenshaw, DM Kraemer, SB Dietrich, M Elitzur, M Teplitz, H Turner, TJ AF Deo, R. P. Crenshaw, D. M. Kraemer, S. B. Dietrich, M. Elitzur, M. Teplitz, H. Turner, T. J. TI Spitzer IRS observations of Seyfert 1.8 and 1.9 galaxies: A comparison with Seyfert 1 and Seyfert 2 SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; galaxies : active; galaxies : Seyfert ID ACTIVE GALACTIC NUCLEI; SPACE-TELESCOPE; INFRARED SPECTROGRAPH; LINE REGION; ISO-SWS; EMISSION; SPECTRA; AGNS; QUASARS; DUST AB We present Spitzer mid-infrared spectra of 12 Seyfert 1.8 and 1.9 galaxies over the 5-38 mu m region. We compare the spectral characteristics of this sample to those of 58 Seyfert 1 and 2 galaxies from the Spitzer archives. An analysis of the spectral shapes, the silicate 10 mu m feature and the emission-line fluxes have enabled us to characterize the mid-IR properties of Seyfert 1.8/1.9s. We find that the EWs of the 10 mu m silicate feature are generally weak in all Seyfert galaxies, as previously reported by several studies. The few Seyfert galaxies in this sample that show deep 10 mu m silicate absorption features are highly inclined and/or merging galaxies. It is likely that these absorption features originate primarily in the dusty interstellar medium of the host galaxy rather than in a dusty torus on parsec scales close to the central engine. We find that the EW of the PAH band at 6.2 mu m correlates strongly with the 20-30 mu m spectral index. Either of these quantities is a good indicator of the amount of starburst contribution to the mid-IR spectra. The spectra of Seyfert 1.8s and 1.9s are dominated by these starburst features, similar to most Seyfert 2s. They show strong PAH bands and a strong red continuum toward 30 mu m. The strengths of the high-ionization forbidden narrow emission lines [O IV] 25.89 mu m, [Ne III] 15.56 mu m, and [Ne V] 14.32 mu m relative to [Ne II] 12.81 mu m are weaker in Seyfert 1.8/1.9s and Seyfert 2s than in Seyfert 1s. The weakness of high-ionization lines in Seyfert 1.8-1.9s is suggestive of intrinsically weak AGN continua and/or stronger star formation activity leading to enhanced [Ne II]. We discuss the implications of these observational results in the context of the unified model of AGNs. C1 [Deo, R. P.; Crenshaw, D. M.] Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. [Kraemer, S. B.] Catholic Univ Amer, Greenbelt, MD 20771 USA. [Kraemer, S. B.; Turner, T. J.] NASA, Goddard Space Flight Ctr, Explorat Universe Div, Greenbelt, MD 20771 USA. [Dietrich, M.] Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. [Elitzur, M.] Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. [Teplitz, H.] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. [Turner, T. J.] Univ Maryland, Dept Phys, Baltimore, MD 21250 USA. RP Deo, RP (reprint author), Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. EM deo@chara.gsu.edu; crenshaw@chara.gsu.edu; stiskraemer@yancey.gsfc.nasa.gov; dietrich@astronomy.ohio-state.edu; moshe@pa.uky.edu; hit@ipac.caltech.edu; turner@milkyway.gsfc.nasa.gov NR 31 TC 50 Z9 50 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2007 VL 671 IS 1 BP 124 EP 135 DI 10.1086/522823 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AL UT WOS:000253331400012 ER PT J AU Kennicutt, RC Calzetti, D Walter, F Helou, G Hollenbach, DJ Armus, L Bendo, G Dale, DA Draine, BT Engelbracht, CW Gordon, KD Prescott, MKM Regan, MW Thornley, MD Bot, C Brinks, E De Blok, E De Mello, D Meyer, M Moustakas, J Murphy, EJ Sheth, K Smith, JDT AF Kennicutt, Robert C., Jr. Calzetti, Daniela Walter, Fabian Helou, George Hollenbach, David J. Armus, Lee Bendo, George Dale, Daniel A. Draine, Bruce T. Engelbracht, Charles W. Gordon, Karl D. Prescott, Moire K. M. Regan, Michael W. Thornley, Michele D. Bot, Caroline Brinks, Elias De Blok, Erwin De Mello, Dulia Meyer, Martin Moustakas, John Murphy, Eric J. Sheth, Kartik Smith, J. D. T. TI Star formation in NGC 5194 (M51a). II. The spatially resolved star formation law SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : individual (M51a, NGC 5194); galaxies : ISM; HII regions; infrared : galaxies; stars : formation ID MULTIBAND IMAGING PHOTOMETER; SPECTRAL ENERGY-DISTRIBUTION; MOLECULAR GAS-DISTRIBUTION; GALACTIC GAMMA-RAYS; RICH HII-REGIONS; SPIRAL STRUCTURE; NEARBY GALAXIES; H-ALPHA; SCHMIDT LAW; FORMATION THRESHOLDS AB We have studied the relationship between the star formation rate (SFR), surface density, and gas surface density in the spiral galaxy M51a (NGC 5194), using multiwavelength data obtained as part of the Spitzer Infrared Nearby Galaxies Survey (SINGS). We introduce a new SFR index based on a linear combination of H alpha emission-line and 24 mu m continuum luminosities, which provides reliable extinction-corrected ionizing fluxes and SFR densities over a wide range of dust attenuations. The combination of these extinction-corrected SFR densities with aperture synthesis H I and CO maps has allowed us to probe the form of the spatially resolved star formation law on scales of 0.5-2 kpc. We find that the resolved SFR versus gas surface density relation is well represented by a Schmidt power law, which is similar in form and dispersion to the disk-averaged Schmidt law. We observe a comparably strong correlation of the SFR surface density with the molecular gas surface density, but no significant correlation with the surface density of atomic gas. The best-fitting slope of the Schmidt law varies from N = 1:37 to 1.56, with zero point and slope that change systematically with the spatial sampling scale. We tentatively attribute these variations to the effects of areal sampling and averaging of a nonlinear intrinsic star formation law. Our data can also be fitted by an alternative parameterization of the SFR surface density in terms of the ratio of gas surface density to local dynamical time, but with a considerable dispersion. C1 [Kennicutt, Robert C., Jr.] Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. [Kennicutt, Robert C., Jr.; Engelbracht, Charles W.; Gordon, Karl D.; Prescott, Moire K. M.; Smith, J. D. T.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. [Calzetti, Daniela] Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. [Calzetti, Daniela; Regan, Michael W.; Meyer, Martin] Space Telescope Sci Inst, Baltimore, MD 21218 USA. [Walter, Fabian] Max Planck Inst Astron, D-69117 Heidelberg, Germany. [Helou, George] CALTECH, Pasadena, CA 91101 USA. [Hollenbach, David J.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Armus, Lee; Bot, Caroline; Sheth, Kartik] Spitzer Sci Ctr, Pasadena, CA 91101 USA. [Bendo, George] Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, London SW7 2AZ, England. [Dale, Daniel A.] Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. [Draine, Bruce T.] Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. [Thornley, Michele D.] Bucknell Univ, Dept Phys & Astron, Lewisburg, PA 17837 USA. [Brinks, Elias] Univ Hertfordshire, Sch Phys Astron & Math, Hatfield AL10 9AB, Herts, England. [De Blok, Erwin] Mt Stromlo & Siding Spring Observ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. [De Mello, Dulia] NASA, Goddard Space Flight Ctr, Lab Observat Cosmol, Greenbelt, MD 20771 USA. [De Mello, Dulia] Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. [Moustakas, John] NYU, Dept Phys, New York, NY 10003 USA. [Murphy, Eric J.] Yale Univ, Dept Astron, New Haven, CT 06520 USA. RP Kennicutt, RC (reprint author), Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England. OI Bot, Caroline/0000-0001-6118-2985; Draine, Bruce/0000-0002-0846-936X; Brinks, Elias/0000-0002-7758-9699 NR 71 TC 321 Z9 322 U1 0 U2 8 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2007 VL 671 IS 1 BP 333 EP 348 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AL UT WOS:000253331400028 ER PT J AU Bauschlicher, CW Liu, YF Ricca, A Mattioda, AL Allamandola, LJ AF Bauschlicher, Charles W., Jr. Liu, Yufei Ricca, Alessandra Mattioda, Andrew L. Allamandola, Louis J. TI Electronic and vibrational spectroscopy of diamondoids and the interstellar infrared bands between 3.35 and 3.55 mu m SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : ISM; ISM : individual (HD 97048, Elias 1); ISM : molecules; methods : numerical; ultraviolet : ISM ID POLYCYCLIC AROMATIC-HYDROCARBONS; DENSITY-FUNCTIONAL THEORY; 3 MICRON SPECTRA; H2O ICE BANDS; METEORITIC NANODIAMONDS; PRESOLAR DIAMONDS; LARGE MOLECULES; EMISSION BANDS; ABSORPTION; DUST AB The electronic and vibrational spectroscopic properties and ionization energies of diamondoids (nano-diamonds, microdiamonds) are computed using density functional theory (DFT). Spectra of both the neutral and cationic forms of diamondoids, ranging in size from C(10)H(16) to C(38)H(42), and the IR spectrum of a diamondoid-PAH hybrid molecule are presented. For the 23 neutral species, the C-H stretching bands fall near 3.47 mu m and are the strongest in the spectra. Diamondoid ionization energies (IEs) are found to be quite large (about 8 eV). The electronic excitation energies of the neutral species are of the same order as the IEs and have very small oscillator strengths (f-values). For the cations, the C-H stretching peak positions differ somewhat from the neutrals and their average integrated band strengths are about half those of the neutrals. The computed electronic excitation energies for the cations are much smaller than those of the neutral species, with f-values that are very small. The neutral diamondoids will absorb most strongly near 3.47 mu m, which is very close to the position of an absorption band associated with dense clouds that has been tentatively attributed to the tertiary C-H stretch of diamond-like carbon. The spectroscopic properties described here imply that 3 mu m emission from highly vibrationally excited diamondoid cations and neutral species should be most intense in regions with strong radiation fields. These results, in conjunction with the observation that the 3.5 mu m emission feature originates very close to the exciting star, strongly supports its assignment in HD 97048 and Elias 1 to diamondoid species. While previous work makes an excellent case for large neutral diamondoids, our work shows that some cation contribution cannot be excluded. The very small f-values explain why so few sources show this emission. C1 [Bauschlicher, Charles W., Jr.; Liu, Yufei; Ricca, Alessandra; Mattioda, Andrew L.; Allamandola, Louis J.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM charles.w.bauschlicher@nasa.gov NR 63 TC 14 Z9 14 U1 2 U2 15 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2007 VL 671 IS 1 BP 458 EP 469 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AL UT WOS:000253331400038 ER PT J AU Colgan, SWJ Schultz, ASB Kaufman, MJ Erickson, EF Hollenbach, DJ AF Colgan, Sean W. J. Schultz, A. S. B. Kaufman, M. J. Erickson, E. F. Hollenbach, D. J. TI NICMOS observations of shocked H-2 in orion SO ASTROPHYSICAL JOURNAL LA English DT Article DE HII regions; infrared : ISM : lines and bands; ISM : individual (OMC-1); ISM : jets and outflows; stars : pre-main-sequence ID HERBIG-HARO OBJECTS; MOLECULAR-HYDROGEN EMISSION; INTERSTELLAR SHOCKS; INFRARED-EMISSION; STAR-FORMATION; LINE EMISSION; NEBULA; CLOUD; OMC-1; WAVES AB HST NICMOS narrowband images of the shocked molecular hydrogen emission in OMC-1 are analyzed to reveal new information on the BN/KL outflow. The outstanding morphological feature of this region is the array of molecular hydrogen "fingers'' emanating from the general vicinity of IRc2 and the presence of several Herbig-Haro objects. The NICMOS images appear to resolve individual shock fronts. This work is a more quantitative and detailed analysis of our data from a previous paper. Line strengths for the H-2 1 - 0 S( 4) plus 2 - 1 S( 6) lines at 1.89 mu m are estimated from measurements with the Paschen-alpha continuum filter F190N at 1.90 mu m and continuum measurements at 1.66 and 2.15 mu m. We compare the observed H-2 line strengths and ratios of the 1.89 and 2.12 mu m 1 - 0 S( 1) lines with models for molecular cloud shock waves. Most of the data cannot be fit by J-shocks but are well matched by C-shocks with shock velocities in the range of 20 - 45 km s(-1) and preshock densities of 104 - 106 cm(-3), similar to values obtained in larger beam studies which averaged over many shocks. There is also some evidence that shocks with higher densities have lower velocities. C1 [Colgan, Sean W. J.; Schultz, A. S. B.; Kaufman, M. J.; Erickson, E. F.; Hollenbach, D. J.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Colgan, SWJ (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM sean.colgan@nasa.gov RI Colgan, Sean/M-4742-2014 NR 49 TC 12 Z9 12 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2007 VL 671 IS 1 BP 536 EP 545 DI 10.1086/522513 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AL UT WOS:000253331400043 ER PT J AU Story, SA Gonthier, PL Harding, AK AF Story, Sarah A. Gonthier, Peter L. Harding, Alice K. TI Population synthesis of radio and gamma-ray millisecond pulsars from the Galactic disk SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : theory; magnetic fields; pulsars : general; radiation mechanisms : nonthermal; stars : neutron ID HIGH-ENERGY EMISSION; X-RAY; YOUNG PULSARS; PARTICLE-ACCELERATION; PAIR FORMATION; MILKY-WAY; SLOT GAPS; DISCOVERY; POLARIZATION; RADIATION AB We present results of a population synthesis of millisecond pulsars from the Galactic disk. Excluding globular clusters, we model the spatial distribution of millisecond pulsars by assuming their birth in the Galactic disk with a random kick velocity and evolve them to the present within the Galactic potential. We assume that normal and millisecond pulsars are standard candles described with a common radio luminosity model that invokes a new relationship between radio core and cone emission suggested by recent studies. In modeling the radio emission beams, we explore the relativistic effects of time delay, aberration, and sweep-back of the open field lines. While these effects are essential to understanding pulse profiles, the phase-averaged flux is adequately described without a relativistic model. We use a polar cap acceleration model for the gamma-ray emission. We present the preliminary results of our recent study and the implications for observing millisecond pulsars with GLAST and AGILE. C1 [Story, Sarah A.; Gonthier, Peter L.] Hope Coll, Dept Phys, Holland, MI 49423 USA. [Harding, Alice K.] NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Story, SA (reprint author), Hope Coll, Dept Phys, 27 Graves Pl, Holland, MI 49423 USA. EM gonthier@hope.edu; harding@twinkie.gsfc.nasa.gov RI Harding, Alice/D-3160-2012 NR 71 TC 70 Z9 70 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2007 VL 671 IS 1 BP 713 EP 726 DI 10.1086/521016 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AL UT WOS:000253331400060 ER PT J AU Miroshnichenko, AS Manset, N Kusakin, AV Chentsov, EL Klochkova, VG Zharikov, SV Gray, RO Grankin, KN Gandet, TL Bjorkman, KS Rudy, RJ Lynch, DK Venturini, CC Mazuk, S Puetter, RC Perry, RB Levato, H Grosso, M Bernabei, S Polcaro, VF Viotti, RF Norci, L Kuratov, KS AF Miroshnichenko, A. S. Manset, N. Kusakin, A. V. Chentsov, E. L. Klochkova, V. G. Zharikov, S. V. Gray, R. O. Grankin, K. N. Gandet, T. L. Bjorkman, K. S. Rudy, R. J. Lynch, D. K. Venturini, C. C. Mazuk, S. Puetter, R. C. Perry, R. B. Levato, H. Grosso, M. Bernabei, S. Polcaro, V. F. Viotti, R. F. Norci, L. Kuratov, K. S. TI Toward understanding the B[e] phenomenon. II. New galactic FSCMa stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; stars : early-type; stars : emission-line; Be ID EMISSION-LINE STARS; IRAS SOURCES; CATACLYSMIC VARIABLES; DATA RELEASE; WARM DUST; CATALOG; NORTHERN; SPECTROSCOPY; CLASSIFICATION; IDENTIFICATION AB FS CMa stars form a group of objects with the B[e] phenomenon that were previously known as unclassified B[e] stars or B[e] stars with warm dust (B[e] WD) until recently. They exhibit strong emission-line spectra and strong IR excesses, most likely due to recently formed circumstellar dust. These properties have been suggested to be due to ongoing or recent rapid mass exchange in binary systems with hot primaries and various types of secondaries. The first paper of this series reported an analysis of the available information about previously known Galactic objects with the B[e] phenomenon, the initial selection of the FS CMa group objects, and a qualitative explanation of their properties. This paper reports the results of our new search for more FS CMa objects in the IRAS Point Source Catalog. We present new photometric criteria for identifying FS CMa stars as well as the first results of our observations of nine new FS CMa group members. With this addition, the FS CMa group has now 40 members, becoming the largest among the dust-forming hot star groups. We also present nine objects with no evidence for the B[e] phenomenon, but with newly discovered spectral line emission and/or strong IR excesses. C1 [Miroshnichenko, A. S.] Univ N Carolina, Dept Phys & Astron, Greensboro, NC 27402 USA. [Manset, N.] CFHT Corp, Kamuela, HI 96743 USA. [Kusakin, A. V.; Kuratov, K. S.] Fesenkov Astrophys Inst, Kamenskoe Plato 050020, Almaty, Kazakhstan. [Kusakin, A. V.] Strernberg Astron Inst, Moscow, Russia. [Chentsov, E. L.; Klochkova, V. G.] Russian Acad Sci, Special Astrophys Observ, Nizhnyj Arkhyz 369167, Russia. [Zharikov, S. V.] Univ Nacl Autonoma Mexico, Inst Astron, Ensenada 22830, Baja California, Mexico. [Gray, R. O.] Appalachian State Univ, Dept Phys & Astron, Boone, NC 28608 USA. [Grankin, K. N.] Ulugh Beg Astron Inst, Tashkent 700052, Uzbekistan. [Gandet, T. L.] Lizard Hollow Observ, Tucson, AZ 85752 USA. [Bjorkman, K. S.] Univ Toledo, Ritter Observ, Toledo, OH 43606 USA. [Rudy, R. J.; Lynch, D. K.; Venturini, C. C.; Mazuk, S.] Aerosp Corp, Los Angeles, CA 90009 USA. [Puetter, R. C.] Univ Calif San Diego, La Jolla, CA 92093 USA. [Perry, R. B.] NASA, Langley Res Ctr, Sci Support Off, Hampton, VA 23681 USA. [Levato, H.; Grosso, M.] Complejo Astron El Leoncito CASLEO, RA-5400 San Juan, Argentina. [Bernabei, S.] Osservatorio Astron Bologna, INAF, I-40127 Bologna, Italy. [Polcaro, V. F.; Viotti, R. F.] INAF, Inst Astrofis Spaziale & Fis Cosm, I-00133 Rome, Italy. [Norci, L.] Dublin City Univ, Sch Phys Sci, Dublin 9, Ireland. [Norci, L.] Dublin City Univ, NCPST, Dublin 9, Ireland. RP Miroshnichenko, AS (reprint author), Univ N Carolina, Dept Phys & Astron, Greensboro, NC 27402 USA. EM a_mirosh@uncg.edu OI Grankin, Konstantin/0000-0001-5707-8448 NR 71 TC 13 Z9 13 U1 2 U2 8 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2007 VL 671 IS 1 BP 828 EP 841 DI 10.1086/523094 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AL UT WOS:000253331400071 ER PT J AU Thejappa, G MacDowall, RJ Kaiser, ML AF Thejappa, G. MacDowall, R. J. Kaiser, M. L. TI Monte Carlo simulation of directivity of interplanetary radio bursts SO ASTROPHYSICAL JOURNAL LA English DT Article DE sun : radio radiation ID INNER SOLAR-WIND; III BURSTS; DENSITY-FLUCTUATIONS; CORONAL SCATTERING; SOURCE REGION; MODEL INTERPRETATION; PLASMA FREQUENCY; ELECTRON-DENSITY; EMISSION; TURBULENCE AB We have developed a Monte Carlo simulation code to study the effects of refraction due to spatial variation of the solar wind density and scattering due to random density fluctuations on directivities, time profiles, and sizes and positions of the apparent sources of the interplanetary type II and type III radio bursts excited at the fundamental (F) and second harmonic (H) of the electron plasma frequency, f(pe). We have focused on the 120 kHz fundamental and harmonic emissions with sources at the heliocentric distances of 0.2097AU(similar to 115 kHz plasma level), and 0.3875AU (similar to 60 kHz plasma level), respectively, and computed the distributions of trajectories of traced rays in a refracting, as well as a refracting and scattering, medium. These distributions show that (1) the scattering by random density fluctuations extends the visibilities of F and H components from similar to 18 degrees to similar to 90 degrees, and from similar to 80 degrees to similar to 150 degrees, respectively; (2) the time profiles constructed using the dispersion of the arrival times of the scattered rays at any given frequency may contain two peaks corresponding to F and H emissions, or a single peak consisting of both F and H components (fundamental followed by the harmonic), or a single H peak depending on the speed of the electron beam and the observer's location; and (3) the scattering broadens the sizes of the fundamental and harmonic point sources to similar to 25 degrees and similar to 37 degrees, and by elevating their apparent radial distances to f/3 and f/2 levels, respectively. We also present simultaneous observations of a type II and a couple of type III radio bursts by Ulysses and Wind spacecraft separated by more than 100 degrees and show that the widely visible radio bursts correspond either to a scattered fundamental, to a refracted or scattered harmonic, or to a mixture of scattered fundamental and harmonic emissions. C1 [Thejappa, G.] Univ Maryland, Dept Astron, College Pk, MD 20742 USA. [MacDowall, R. J.; Kaiser, M. L.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Thejappa, G (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM thejappa@astro.umd.edu RI MacDowall, Robert/D-2773-2012 NR 65 TC 18 Z9 18 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2007 VL 671 IS 1 BP 894 EP 906 DI 10.1086/522664 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AL UT WOS:000253331400077 ER PT J AU Jackiewicz, J Gizon, L Birch, AC Duvall, TL AF Jackiewicz, J. Gizon, L. Birch, A. C. Duvall, T. L., Jr. TI Time-distance helioseismology: Sensitivity of f-mode travel times to flows SO ASTROPHYSICAL JOURNAL LA English DT Article DE convection; scattering; Sun : helioseismology; Sun : oscillations; waves ID SOLAR; SURFACE AB Time-distance helioseismology has shown that f-mode travel times contain information about horizontal flows in the Sun. The purpose of this study is to provide a simple interpretation of these travel times. We study the interaction of surface gravity waves with horizontal flows in an incompressible, plane-parallel solar atmosphere. We show that for uniform flows less than roughly 250 m s(-1), the travel-time shifts are linear in the flow amplitude. For stronger flows, perturbation theory up to third order is needed to model waveforms. The case of small-amplitude spatially varying flows is treated using the first-order Born approximation. We derive two-dimensional Frechet kernels that give the sensitivity of travel-time shifts to local flows. We show that the effect of flows on travel times depends on wave damping and on the direction from which the observations are made. The main physical effect is the advection of the waves by the flow rather than the advection of wave sources or the effect of flows on wave damping. We compare the two-dimensional sensitivity kernels with simplified three-dimensional kernels that only account for wave advection and assume a vertical line of sight. We find that the three-dimensional f-mode kernels approximately separate in the horizontal and vertical coordinates, with the horizontal variations given by the simplified two-dimensional kernels. This consistency between quite different models gives us confidence in the usefulness of these kernels for interpreting quiet-Sun observations. C1 [Jackiewicz, J.; Gizon, L.] Max Planck Inst Sonnensystemfors, D-37191 Katlenburg Duhm, Germany. [Birch, A. C.] NWRA, CoRA, Boulder, CO 80301 USA. [Duvall, T. L., Jr.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Jackiewicz, J (reprint author), Max Planck Inst Sonnensystemfors, D-37191 Katlenburg Duhm, Germany. EM jackiewicz@mps.mpg.de RI Gizon, Laurent/B-9457-2008; Duvall, Thomas/C-9998-2012 NR 16 TC 18 Z9 18 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2007 VL 671 IS 1 BP 1051 EP 1064 DI 10.1086/522914 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265AL UT WOS:000253331400092 ER PT J AU Tritschler, A Muller, DAN Schlichenmaier, R Hagenaar, HJ AF Tritschler, A. Mueller, D. A. N. Schlichenmaier, R. Hagenaar, H. J. TI Fine structure of the net circular polarization in a sunspot penumbra SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE magnetic fields; sun : photosphere; sunspots ID TO-LIMB VARIATION; SPECTRAL SIGNATURE; MAGNETIC-FIELDS; FLUX TUBES; POLARIMETER AB We present novel evidence for fine structure observed in the net circular polarization (NCP) of a sunspot penumbra based on spectropolarimetric measurements utilizing the Zeeman-sensitive Fe I 630.2 nm line. For the first time we detect filamentary organized fine structure of the NCP on spatial scales that are similar to the inhomogeneities found in the penumbral flow field. We also observe an additional property of the visible NCP, a zero-crossing of the NCP in the outer parts of the center-side penumbra, which has not been recognized before. In order to interpret the observations we solve the radiative transfer equations for polarized light in a model penumbra with embedded magnetic flux tubes. We demonstrate that the observed zero-crossing of the NCP can be explained by an increased magnetic field strength inside magnetic flux tubes in the outer penumbra combined with a decreased magnetic field strength in the background field. Our results strongly support the concept of the uncombed penumbra. C1 [Tritschler, A.] Natl Solar Observ, Sunspot, NM 88349 USA. [Mueller, D. A. N.] NASA, Goddard Space Flight Ctr, European Space Agcy, Greenbelt, MD 20771 USA. [Schlichenmaier, R.] Kiepenheuer Inst Sonnenphys, D-79104 Freiburg, Germany. [Hagenaar, H. J.] Org ADBS, Lockheed Martin Adv Technol Ctr, Palo Alto, CA 94304 USA. RP Tritschler, A (reprint author), Natl Solar Observ, Sacramento Peak,POB 62, Sunspot, NM 88349 USA. EM ali@nso.edu; dmueller@esa.nascom.nasa.gov; schliche@kis.uni-freiburg.de; hagenaar@lmsal.com NR 24 TC 22 Z9 22 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA J9 ASTROPHYS J LETT JI Astrophys. J. Lett. PD DEC 10 PY 2007 VL 671 IS 1 BP L85 EP L88 DI 10.1086/524872 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 289QV UT WOS:000255069900022 ER PT J AU Chang, WS Jung, YD AF Chang, Won-Seok Jung, Young-Dae TI Quantum effects on polarization bremsstrahlung from electron-atom collisions in partially ionized dense hydrogen plasmas SO PHYSICS LETTERS A LA English DT Article ID SCATTERING PROCESSES AB The quantum effects on the polarization bremsstrahlung emission due to the low-energy electron-atom collisions are investigated in partially ionized dense hydrogen plasmas. The impact parameter analysis is employed to describe the motion of the projectile electron in order to investigate the variation of the bremsstrahlung emission spectrum as a function of the impact parameter, de Broglie wave length, Debye length, and radiation photon energy. The results show that the quantum effects strongly suppress the polarization bremsstarhlung emission. It is also found that the polarization bremsstarhlung emission cross section shows the maximum value at the position of the Bohr radius. It is interesting to note that the quantum effects are found to be more important than the screening effects in the polarization bremsstarhlung emission. (c) 2007 Elsevier B.V. All fights reserved. C1 [Chang, Won-Seok; Jung, Young-Dae] Hanyang Univ, Dept Appl Phys, Ansan 426791, South Korea. [Jung, Young-Dae] NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. RP Jung, YD (reprint author), Hanyang Univ, Dept Appl Phys, Ansan 426791, South Korea. EM ydjung@hanyang.ac.kr NR 17 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD DEC 10 PY 2007 VL 372 IS 1 BP 52 EP 55 DI 10.1016/j.physleta.2007.07.007 PG 4 WC Physics, Multidisciplinary SC Physics GA 242AW UT WOS:000251697900011 ER PT J AU Lau, KM Kim, KM AF Lau, K. M. Kim, K. M. TI Cooling of the Atlantic by Saharan dust SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AEROSOL; SURFACE; TRANSPORT; EVENTS; IMPACT; SMOKE; WEST AB Using aerosol optical depth, sea surface temperature, top-of-the-atmosphere solar radiation flux, and oceanic mixed-layer depth from diverse data sources that include NASA satellites, NCEP reanalysis, in situ observations, as well as long-term dust records from Barbados, we examine the possible relationships between Saharan dust and Atlantic sea surface temperature. Results show that the estimated anomalous cooling pattern of the Atlantic during June 2006 relative to June 2005 due to attenuation of surface solar radiation by Saharan dust remarkably resemble observations, accounting for approximately 30-40% of the observed change in sea surface temperature. Historical data analysis show that there is a robust negative correlation between atmospheric dust loading and Atlantic SST consistent with the notion that increased (decreased) Saharan dust is associated with cooling (warming) of the Atlantic during the early hurricane season (July-August September). C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Lau, KM (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 613, Greenbelt, MD 20771 USA. EM william.k.lau@nasa.gov RI Kim, Kyu-Myong/G-5398-2014; Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 20 TC 52 Z9 53 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 8 PY 2007 VL 34 IS 23 AR L23811 DI 10.1029/2007GL031538 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 239NL UT WOS:000251524900004 ER PT J AU Miller, JR Chen, YH Russell, GL Francis, JA AF Miller, James R. Chen, Yonghua Russell, Gary L. Francis, Jennifer A. TI Future regime shift in feedbacks during Arctic winter SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLIMATE-CHANGE; RIVER FLOW; MODEL; OCEAN; VARIABILITY; CLOUD AB The Arctic is among the regions where climate is changing most rapidly today. Climate change is amplified by a variety of positive feedbacks, many of which are linked with changes in water vapor, cloud cover, and other cloud properties. We use a global climate model to examine several of these feedbacks, with a particular emphasis on determining whether there are significant temporal changes in these feedbacks that would make them stronger or weaker during the 21st century. The model results indicate that one of the significant positive feedbacks on Arctic surface air temperature in winter weakens substantially toward the end of the 21st century. The feedback loop begins with a temperature increase that produces increases in water vapor, cloud cover, and cloud optical depth which increase the downward longwave flux by 30 Wm(-2) by 2060 which then increases the surface air temperature. C1 Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08901 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Miller, JR (reprint author), Rutgers State Univ, Inst Marine & Coastal Sci, 71 Dudley Rd, New Brunswick, NJ 08901 USA. EM miller@marine.rutgers.edu NR 23 TC 3 Z9 3 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 8 PY 2007 VL 34 IS 23 AR L23707 DI 10.1029/2007GL031826 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 239NL UT WOS:000251524900006 ER PT J AU Balis, D Koukouli, ME Brinksma, EJ Kroon, M Veefkind, JP Labow, G McPeters, RD AF Balis, D. Koukouli, M. E. Brinksma, E. J. Kroon, M. Veefkind, J. P. Labow, G. McPeters, R. D. TI Validation of Ozone Monitoring Instrument total ozone column measurements using Brewer and Dobson spectrophotometer ground-based observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ABSORPTION-COEFFICIENTS; NETWORK; TOMS; GOME AB [1] In this paper we present validation results of the total ozone column data products of the Ozone Monitoring Instrument (OMI) on board the NASA EOS-AURA satellite through comparisons with ground-based observations by Dobson and Brewer spectrophotometer instruments. Quality-controlled and archived total ozone column data from these ground-based instruments located at stations worldwide have been used to validate more than 2 a of total ozone column observations from OMI. There are two operationally available satellite total ozone column data products, based on the OMI-TOMS and the OMI-DOAS retrieval algorithms, respectively. Validation with ground-based data focused on global comparisons and seasonal dependence and the possible dependence on latitude and solar zenith angle. Our results show a globally averaged agreement of better than 1% for OMI-TOMS data and better than 2% for OMI-DOAS data with the ground-based observations. The OMI-TOMS data product is shown to be of high overall quality with no significant dependence on solar zenith angle or latitude. The OMI-DOAS data product shows no significant dependence on latitude except for the high latitudes of the Southern Hemisphere where it systematically overestimates the total ozone value. In addition a significant dependence on solar zenith angle is found between OMI-DOAS and ground-based data. Comparisons of satellite and ground-based data tend to show a marginal seasonal dependence even though it remains unclear whether this dependence originates from the ground-based or spaceborne observations. C1 Aristotle Univ Thessaloniki, Dept Phys, Lab Atmospher Phys, GR-54124 Thessaloniki, Greece. Royal Netherlands Meteorol Inst, NL-3730 AE De Bilt, Netherlands. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Balis, D (reprint author), Aristotle Univ Thessaloniki, Dept Phys, Lab Atmospher Phys, Box 149, GR-54124 Thessaloniki, Greece. EM balis@auth.gr RI McPeters, Richard/G-4955-2013; Koukouli, MariLiza/A-2249-2015; OI McPeters, Richard/0000-0002-8926-8462; Koukouli, MariLiza/0000-0002-7509-4027; Balis, Dimitris/0000-0003-1161-7746 NR 25 TC 81 Z9 87 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 8 PY 2007 VL 112 IS D24 AR D24S46 DI 10.1029/2007JD008796 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 239OB UT WOS:000251526500001 ER PT J AU Pawson, S Stajner, I Kawa, SR Hayashi, H Tan, WW Nielsen, JE Zhu, Z Chang, LP Livesey, NJ AF Pawson, Steven Stajner, Ivanka Kawa, S. Randolph Hayashi, Hiroo Tan, Wei-Wu Nielsen, J. Eric Zhu, Zhengxin Chang, Lang-Ping Livesey, Nathaniel J. TI Stratospheric transport using 6-h-averaged winds from a data assimilation system SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPICAL TROPOPAUSE TEMPERATURES; GENERAL-CIRCULATION MODEL; OZONE DATA; 3-DIMENSIONAL SIMULATIONS; GLOBAL CHEMISTRY; AGE SPECTRA; WATER-VAPOR; ART.; TRAJECTORIES; SATELLITE AB [1] Stratospheric transport calculated using assimilated winds has been shown to be too fast in many cases, because of excessive mixing and an overstrong residual circulation. It is shown that the use of 6-h-averaged wind fields instead of instantaneous analyses can substantially reduce this problem for NASA's Goddard Earth Observing System version 4 (GEOS- 4) sequential data assimilation system. Two examples are used to illustrate impacts in an off-line chemistry transport model. An age-of-air computation shows that the stratosphere becomes substantially older when time-averaged winds are used, yet still not as old as that determined from observations. An ozone assimilation experiment reveals improvements in the spatial structure of assimilated ozone, better agreement with independent observations, and a 40-60% reduction in observation-minus-forecast residuals. The averaged meteorological fields have also been incorporated in the on-line transport computations: This is equivalent to using a 6-h square-wave filter at the analysis times. Sub-6-h noise in the system is substantially reduced with this approach. Two additional examples of transport are shown. A simulation of 2004-2005 shows that the descent of N2O in the Arctic polar vortex is represented more accurately than in previous studies. A tape recorder signal is evident in the tropical moisture; it ascends about 30% faster than that in the real atmosphere. In summary, the use of 6-h-averaged winds substantially improves the transport characteristics of the assimilated data, although the circulation remains too fast. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Sci Applicat Int Corp, Beltsville, MD USA. NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD USA. Sci Syst & Applicat Inc, Lanham, MD USA. Jet Propuls Lab, Pasadena, CA USA. RP Pawson, S (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. RI Kawa, Stephan/E-9040-2012; Stajner, Ivanka/B-5228-2009; Pawson, Steven/I-1865-2014 OI Stajner, Ivanka/0000-0001-6103-3939; Pawson, Steven/0000-0003-0200-717X NR 45 TC 23 Z9 23 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 8 PY 2007 VL 112 IS D23 AR D23103 DI 10.1029/2006JD007673 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 239NS UT WOS:000251525600001 ER PT J AU D'Sa, EJ Miller, RL Mckee, BA AF D'Sa, Eurico J. Miller, Richard L. Mckee, Brent A. TI Suspended particulate matter dynamics in coastal waters from ocean color: Application to the northern Gulf of Mexico SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BIOOPTICAL PROPERTIES; MISSISSIPPI RIVER; COEFFICIENTS; ABSORPTION; LOUISIANA; SEAWIFS; USA AB [1] Suspended particulate matter (SPM) plays an important role in primary production, pollutant transport, and other biogeochemical processes in coastal marine environments. We present an empirical two-band ocean color remote sensing reflectance algorithm (R(rs)670/R(rs)555) for SPM concentrations developed using field measurements obtained in coastal waters influenced by the Mississippi River in 2000, 2002, and 2004. The ratio algorithm was also found to be highly correlated to backscattering coefficient (b(bp)(555), r(2) = 0.96), the backscattering ratio (bbp(555)/b(p)(555), r(2) = 0.82) and the spectral backscattering slope (g, r(2) = 0.72) in March 2002, a period with large hydrographic variability in the study area. Strong correlations between water column b(bp)(555), SPM and nonalgal absorption anap(443) suggest the dominant influence of nonalgal particles on bbp. SeaWiFS derived SPM and g distributions indicated event-based variability linked to energetic disturbances such as frontal passages, resuspension, and river discharge that with b(bp)/b(p) could reveal refractive index and particle size characteristics in the coastal environment. C1 Louisiana State Univ, Inst Coastal Studies, Dept Oceanog & Coastal Sci, Baton Rouge, LA 70803 USA. NASA, Stennis Space Ctr, Div Sci & Technol, Mississippi State, MS USA. Univ N Carolina, Dept Marine Sci, Chapel Hill, NC USA. RP D'Sa, EJ (reprint author), Louisiana State Univ, Inst Coastal Studies, Dept Oceanog & Coastal Sci, Baton Rouge, LA 70803 USA. NR 14 TC 45 Z9 46 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 7 PY 2007 VL 34 IS 23 AR L23611 DI 10.1029/2007GL031192 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 239NK UT WOS:000251524800002 ER PT J AU Smith, T Thompson, DR Wettergreen, DS Cabrol, NA Warren-Rhodes, KA Weinstein, SJ AF Smith, Trey Thompson, David R. Wettergreen, David S. Cabrol, Nathalie A. Warren-Rhodes, Kimberley A. Weinstein, Shmuel J. TI Life in the Atacama: Science autonomy for improving data quality SO JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES LA English DT Article AB [1] "Science autonomy'' refers to exploration robotics technologies involving onboard science analysis of collected data. These techniques enable a rover to make adaptive decisions about which measurements to collect and transmit. Science autonomy can compensate for limited communications bandwidth by ensuring that planetary scientists receive those images and spectra that best meet mission goals. Here, we present the results of autonomous science experiments performed in the Atacama Desert of Chile during the Life in the Atacama (LITA) rover field campaign. We aim to provide an overview of autonomous science principles and examine their integration into the LITA operations strategy. We present experiments in four specific autonomous science domains: (1) autonomously responding to evidence of life with more detailed measurements; (2) rock detection for site profiling and selective data return; (3) tactical replanning to efficiently map the distribution of life; (4) detecting novel images and geologic unit boundaries in image sequences. In each of these domains we demonstrate improvements in the quality of returned data through autonomous analysis of imagery. C1 Carnegie Mellon Univ, Inst Robot, Pittsburgh, PA 15213 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Carnegie Mellon Univ, Mol Biosensor & Imaging Ctr, Pittsburgh, PA 15213 USA. RP Smith, T (reprint author), Carnegie Mellon Univ, Inst Robot, 5000 Forbes Ave, Pittsburgh, PA 15213 USA. NR 43 TC 10 Z9 10 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-BIOGEO JI J. Geophys. Res.-Biogeosci. PD DEC 7 PY 2007 VL 112 IS G4 AR G04S03 DI 10.1029/2006JG000315 PG 23 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 239OF UT WOS:000251526900001 ER PT J AU Stevenson, TO Mercer, KB Cox, EA Szewczyk, NJ Conley, CA Hardin, JD Benian, GM AF Stevenson, Tesheka O. Mercer, Kristina B. Cox, Elisabeth A. Szewczyk, Nathaniel J. Conley, Catharine A. Hardin, Jeffrey D. Benian, Guy M. TI unc-94 encodes a tropomodulin in Caenorhabditis elegans SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE striated muscle; myofibrils; thin filaments; tropomodulin; C. elegans ID BODY-WALL MUSCLE; C-ELEGANS; POINTED ENDS; THIN-FILAMENTS; CRYSTAL-STRUCTURE; ACTIN-FILAMENTS; STRIATED-MUSCLE; GENE-PRODUCT; PROTEIN; LOCALIZATION AB unc-94 is one of about 40 genes in Caenorhabditis elegans that, when mutant, displays an abnormal muscle phenotype. Two mutant alleles of unc-94, su177 and sf20, show reduced motility and brood size and disorganization of muscle structure. In unc-94 mutants, immunofluorescence microscopy shows that a number of known sarcomeric proteins are abnormal, but the most dramatic effect is in the localization of F-actin, with some abnormally accumulated near muscle cell-to-cell boundaries. Electron microscopy shows that unc-94(sf20) mutants have large accumulations of thin filaments near the boundaries of adjacent muscle cells. Multiple lines of evidence prove that unc-94 encodes a tropomodulin, a conserved protein known from other systems to bind to both actin and tropomyosin at the pointed ends of actin thin filaments. su177 is a splice site mutation in intron 1, which is specific to one of the two unc-94 isoforms, isoform a; sf20 has a stop codon in exon 5, which is shared by both isoform a and isoform b. The use of promoter-green fluorescent protein constructs in transgenic animals revealed that unc-94a is expressed in body wall, vulval and uterine muscles, whereas unc-94b is expressed in pharyngeal, anal depressor, vulval and uterine muscles and in spermatheca and intestinal epithelial cells. By Western blot, anti-UNC-94 antibodies detect polypeptides of expected size from wild type, wild-type-sized proteins of reduced abundance from unc-94(su177), and no detectable unc-94 products from unc-94(sf20). Using these same antibodies, UNC-94 localizes as two closely spaced parallel lines flanking the M-lines, consistent with localization to the pointed ends of thin filaments. In addition, UNC-94 is localized near muscle cell-to-cell boundaries. (C) 2007 Elsevier Ltd. All rights reserved. C1 [Stevenson, Tesheka O.; Mercer, Kristina B.; Benian, Guy M.] Emory Univ, Dept Pathol, Atlanta, GA 30322 USA. [Stevenson, Tesheka O.] Emory Univ, Grad Div Biol & Biomed Sci, Atlanta, GA 30322 USA. [Cox, Elisabeth A.; Hardin, Jeffrey D.] Univ Wisconsin, Dept Zool, Madison, WI 53706 USA. [Szewczyk, Nathaniel J.; Conley, Catharine A.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Szewczyk, Nathaniel J.] Univ Pittsburgh, Dept Biol Sci, Pittsburgh, PA 15260 USA. RP Benian, GM (reprint author), Emory Univ, Dept Pathol, Atlanta, GA 30322 USA. EM pathgb@emory.edu OI Paulson, Elisabeth/0000-0002-5255-078X; Szewczyk, Nathaniel/0000-0003-4425-9746 FU NIAMS NIH HHS [R01 AR052133, AR052133, R01 AR054342-01A1, R01 AR052133-01A1S1, R01 AR052133-02]; NIGMS NIH HHS [R01 GM058038, T32 GM008490, GM58038] NR 60 TC 13 Z9 13 U1 0 U2 2 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD DEC 7 PY 2007 VL 374 IS 4 BP 936 EP 950 DI 10.1016/j.jmb.2007.10.005 PG 15 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 242CA UT WOS:000251700900009 PM 17976644 ER PT J AU Cirtain, JW Golub, L Lundquist, L van Ballegooijen, A Savcheva, A Shimojo, M DeLuca, E Tsuneta, S Sakao, T Reeves, K Weber, M Kano, R Narukage, N Shibasaki, K AF Cirtain, J. W. Golub, L. Lundquist, L. van Ballegooijen, A. Savcheva, A. Shimojo, M. DeLuca, E. Tsuneta, S. Sakao, T. Reeves, K. Weber, M. Kano, R. Narukage, N. Shibasaki, K. TI Evidence for Alfven waves in solar x-ray jets SO SCIENCE LA English DT Article ID MAGNETOHYDRODYNAMIC TURBULENCE; WIND; TELESCOPE; DYNAMICS AB Coronal magnetic fields are dynamic, and field lines may misalign, reassemble, and release energy by means of magnetic reconnection. Giant releases may generate solar flares and coronal mass ejections and, on a smaller scale, produce x-ray jets. Hinode observations of polar coronal holes reveal that x-ray jets have two distinct velocities: one near the Alfven speed (similar to 800 kilometers per second) and another near the sound speed ( 200 kilometers per second). Many more jets were seen than have been reported previously; we detected an average of 10 events per hour up to these speeds, whereas previous observations documented only a handful per day with lower average speeds of 200 kilometers per second. The x-ray jets are about 2 x 10(3) to 2 x 10(4) kilometers wide and 1 x 10(5) kilometers long and last from 100 to 2500 seconds. The large number of events, coupled with the high velocities of the apparent outflows, indicates that the jets may contribute to the high-speed solar wind. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Nobeyama Solar Radio Observ, Nagano 3841305, Japan. Natl Astron Observ Japan, Tokyo 1818588, Japan. Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. RP Cirtain, JW (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM Jonathan.W.Cirtain@nasa.gov RI Reeves, Katharine/P-9163-2014; DeLuca, Edward/L-7534-2013; Shimojo, Masumi/J-2605-2016 OI DeLuca, Edward/0000-0001-7416-2895; Shimojo, Masumi/0000-0002-2350-3749 NR 14 TC 249 Z9 251 U1 1 U2 15 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 7 PY 2007 VL 318 IS 5856 BP 1580 EP 1582 DI 10.1126/science.1147050 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 238BG UT WOS:000251421700032 PM 18063786 ER PT J AU O'Keeffe, J Cozmuta, I Bose, D Stolc, V AF O'Keeffe, James Cozmuta, Ioana Bose, Deepak Stolc, Viktor TI A predictive MD-Nernst-Planck model for transport in alpha-hemolysin: Modeling anisotropic ion currents SO CHEMICAL PHYSICS LA English DT Article DE ion channels; Poisson-Nernst-Planck; alpha-hemolysin; conductance; ion currents ID MOLECULAR-DYNAMICS; DIELECTRIC-CONSTANTS; BIOLOGICAL CHANNEL; POTASSIUM CHANNEL; POISSON-BOLTZMANN; ESCHERICHIA-COLI; PERMEATION; CONDUCTANCE; PROTEINS; SIMULATIONS AB A multiscale simulation approach, combining molecular dynamics (MD) and Poisson-Nernst-Planck (PNT) models is used to predict voltage-driven KCI current flow through an alpha-hemolysin channel. I-V characteristics are calculated for salt concentrations ranging from 50 mM to 3 M. The results show that the fixed charge distribution in the pore walls acts like a macrodipole and introduces a diffusion current component that is responsible for the well-established anisotropic current response. We show that for KCI concentrations in the biological range (50-100 mM), where the Debye length is calculated to be similar to 4 A, ion currents are dominated by the diffusion component. Conversely, for KCI concentrations in excess of 1 M ion currents approach an isotropic, surface chemistry invariant limit. We calculate 0.1 M I-V characteristics for a range of protein dielectric constant epsilon(p) and show that epsilon(P) similar to 21, is appropriate to account for protein relaxation and self-energy polarization contributions, and is necessary to avoid overestimating the ion current. We show that a generalize form of the Goldman-Hodgkin-Katz (GHK) current equation, using the calculated channel voltage profile captures the current rectifying nature of the alpha-hemolysin channel. Published by Elsevier B.V. C1 [O'Keeffe, James; Cozmuta, Ioana; Bose, Deepak; Stolc, Viktor] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP O'Keeffe, J (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM jokeeffe@mail.arc.nasa.gov NR 32 TC 6 Z9 6 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD DEC 6 PY 2007 VL 342 IS 1-3 BP 25 EP 32 DI 10.1016/j.chemphys.2007.09.013 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 244HR UT WOS:000251857500003 ER PT J AU Mlynczak, MG Martin-Torres, FJ Marshall, BT Thompson, RE Williams, J Turpin, T Kratz, DP Russell, JM Woods, T Gordley, LL AF Mlynczak, Martin G. Martin-Torres, F. Javier Marshall, B. Thomas Thompson, R. Earl Williams, Joshua Turpin, Timothy Kratz, David P. Russell, James M., III Woods, Tom Gordley, Larry L. TI Evidence for a solar cycle influence on the infrared energy budget and radiative cooling of the thermosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NITRIC-OXIDE; EMISSION; MISSION AB We present direct observational evidence for solar cycle influence on the infrared energy budget and radiative cooling of the thermosphere. By analyzing nearly five years of data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, we show that the annual mean infrared power radiated by the nitric oxide (NO) molecule at 5.3 mu m has decreased by a factor of 2.9. This decrease is correlated (r = 0.96) with the decrease in the annual mean F10.7 solar index. Despite the sharp decrease in radiated power (which is equivalent to a decrease in the vertical integrated radiative cooling rate), the variability of the power as given in the standard deviation of the annual means remains approximately constant. A simple relationship is shown to exist between the infrared power radiated by NO and the F10.7 index, thus providing a fundamental relationship between solar activity and the thermospheric cooling rate for use in thermospheric models. The change in NO radiated power is also consistent with changes in absorbed ultraviolet radiation over the same time period. Computations of radiated power using an empirical model show much less variability than observed by SABER. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. G&A Tech Software, Newport News, VA 23606 USA. Hampton Univ, Analyt Serv & Mat Inc, Hampton, VA 23666 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23666 USA. Utah State Univ, Dept Elect & Comp Engn, Logan, UT 84322 USA. Atmospher & Space Phys Lab, Boulder, CO 80303 USA. RP Mlynczak, MG (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA. EM m.g.mlynczak@nasa.gov RI Mlynczak, Martin/K-3396-2012; Martin-Torres, Francisco Javier/G-6329-2015 OI Martin-Torres, Francisco Javier/0000-0001-6479-2236 NR 13 TC 22 Z9 22 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 6 PY 2007 VL 112 IS A12 AR A12302 DI 10.1029/2006JA012194 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 239OW UT WOS:000251528600001 ER PT J AU Nikolaev, P Gorelik, O Allada, RK Sosa, E Arepalli, S Yowell, L AF Nikolaev, Pavel Gorelik, Olga Allada, Rama Kumar Sosa, Edward Arepalli, Sivaram Yowell, Leonard TI Soft-bake purification of single-walled carbon nanotubes produced by pulsed laser vaporizationt SO JOURNAL OF PHYSICAL CHEMISTRY C LA English DT Article ID GROWTH; SPECTROSCOPY; ABLATION; PLUME AB Metal impurities within as-produced single-walled carbon nanotubes (SWCNTs) are generally coated with thick shells of graphitic carbon, which prevent the. acid treatments commonly used in SWCNT purification from attacking the metals. The purpose of this study was to determine a more effective and efficient means for the removal of metal impurities from SWCNTs produced by pulsed laser vaporization (PLV). The method investigated was a modified version of a soft-bake purification procedure developed at Rice University, and in the current work, the soft-bake temperature suitable for PLV-produced SWCNTs was determined, and several samples were purified. The quality of material was determined using the standard protocol developed at NASA Johnson Space Center (JSC), and data was collected for several samples in order to determine the consistency and reproducibility of the purification yield and purity. The properties and quality of soft-bake purified material were compared with those of several equivalent materials purified by the JSC standard purification method. It is found that this modified procedure resulted in better purity of SWCNTs, while reducing the purification time by two-thirds. C1 ERC Incorporated, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Nikolaev, P (reprint author), ERC Incorporated, Houston, TX 77058 USA. EM pasha.nikolaev-1@nasa.gov RI Arepalli, Sivaram/A-5372-2010; Nikolaev, Pavel/B-9960-2009 NR 16 TC 7 Z9 7 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1932-7447 J9 J PHYS CHEM C JI J. Phys. Chem. C PD DEC 6 PY 2007 VL 111 IS 48 BP 17678 EP 17683 DI 10.1021/jp070149y PG 6 WC Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 236GV UT WOS:000251291900003 ER PT J AU Bronikowski, MJ AF Bronikowski, Michael J. TI Longer nanotubes at lower temperatures: The influence of effective activation energies on carbon nanotube growth by thermal chemical vapor deposition SO JOURNAL OF PHYSICAL CHEMISTRY C LA English DT Article ID CATALYTIC GROWTH; DEPENDENT GROWTH; BUNDLE ARRAYS; MECHANISM; DIFFUSION; ACETYLENE; SURFACES; KINETICS; SCALE; FILM AB Growth of carbon nanotubes (CNTs) by metal-catalyzed thermal chemical vapor deposition (CVD) upon flat silicon substrates is studied as a function of growth temperature. It is found that the CNT growth rate at a given temperature is constant for a certain amount of growth time, after which growth ceases; the product of the growth rate and the growth time gives the ultimate length of the CNTs. Both the growth rate and the growth time are found to depend on the CVD temperature, and this dependence is such that the ultimate CNT length increases as temperature decreases; that is, longer CNTs can be grown at lower temperatures than at higher temperatures. This surprising and counter-intuitive result reflects the interaction of competing factors affecting the CNT growth: the rate at which carbon is incorporated into growing CNTs versus the rate at which catalytic metal particles become inactive. Both of these rates are found to have an Arrhenius form of temperature dependence, with activation energies of 2.0 and 3.4 eV, respectively, when an Al2O3 diffusion barrier layer is used. These energies are interpreted as "effective" activation barriers arising from activation energy contributions from multiple chemical processes. CNT bundles as long as one millimeter have been grown at a temperature of 600 degrees C. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bronikowski, MJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Michael.J.Bronikowski@jpl.nasa.gov NR 42 TC 30 Z9 30 U1 3 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1932-7447 J9 J PHYS CHEM C JI J. Phys. Chem. C PD DEC 6 PY 2007 VL 111 IS 48 BP 17705 EP 17712 DI 10.1021/jp071079y PG 8 WC Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 236GV UT WOS:000251291900007 ER PT J AU Biris, AS Schmitt, TC Little, RB Li, Z Xu, Y Biris, AR Lupu, D Dervishi, E Trigwell, S Miller, DW Rahman, Z AF Biris, Alexandru S. Schmitt, Thomas C. Little, Reginald B. Li, Zhongrui Xu, Yang Biris, Alexandru R. Lupu, Dan Dervishi, Enkeleda Trigwell, Steve Miller, Dwight W. Rahman, Zia TI Influence of the RF excitation of the catalyst system on the morphology of multiwalled carbon nanotubes (Retracted article. See vol. 116, pg. 18571, 2012) SO JOURNAL OF PHYSICAL CHEMISTRY C LA English DT Article; Retracted Publication ID GROWTH; CCVD; DECOMPOSITION; ACETYLENE; HYDROGEN; SUPPORT AB Multiwalled carbon nanotubes were synthesized by catalytic chemical vapor deposition using two different methods of heating. By one method, an external resistive tube furnace was used, whereas the other method involved heating with radio frequency excitation by induction coil. A comprehensive comparison was made between these two methods with regards to feed gas utilization, nanotube growth efficiency, nanotube product characterization and morphology, and the formation of amorphous carbon and gaseous byproducts. The carbon nanotubes synthesized using radio frequency excitation exhibited smaller outer diameters, fewer carbon layers, less amorphous carbon, and superior crystalline properties than those produced by external tube furnace. The radio frequency process resulted in more rapid and sustained growth rates of the nanotubes and more efficient use of the carbon source. The reason for these enhanced effects by inductive heating may be due not only to the internally produced thermodynamic heat flow characteristics but perhaps also to induced electron currents generated within the magnetic and metallic catalytic clusters due to RF. C1 Univ Arkansas, Nanotechnol Ctr, Little Rock, AR 72204 USA. Univ Arkansas, Dept Appl Sci, Little Rock, AR 72204 USA. US FDA, Natl Ctr Toxicol Res, Jefferson, AR 72079 USA. Elizabeth City State Univ, Dept Chem, Elizabeth City, NC 27909 USA. Natl Inst Res & Dev Isotop & Mol Technol, R-400293 Cluj Napoca, Romania. NASA, Electrostat & Surface Phys Lab, Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. Univ Cent Florida, Adv Mat Proc & Anal Ctr, Orlando, FL 32826 USA. RP Biris, AS (reprint author), Univ Arkansas, Nanotechnol Ctr, Little Rock, AR 72204 USA. EM asbiris@ualr.edu RI Biris, Alexandru/A-8507-2010; Lupu, Dan/C-3346-2009; Dervishi, Enkeleda/B-2239-2010; Biris, Alexandru /C-4517-2011 NR 22 TC 18 Z9 18 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1932-7447 J9 J PHYS CHEM C JI J. Phys. Chem. C PD DEC 6 PY 2007 VL 111 IS 48 BP 17970 EP 17975 DI 10.1021/jp0740346 PG 6 WC Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 236GV UT WOS:000251291900046 ER PT J AU Darcy, E AF Darcy, Eric TI Screening Li-ion batteries for internal shorts SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 13th International Meeting on Lithium Batteries CY JUN 18-23, 2006 CL Biarritz, FRANCE SP CNRS DE Li-ion; internal short; screening AB A Li-ion polymer pouch cell battery design for a spacesuit developed an internal short during ground storage. A detailed failure investigation found that native contamination was the most probable root cause as the failure mechanism was successfully replicated. Lessons learned are applicable to the implementation of most Li-ion cell designs for critical applications. Published by Elsevier B.V. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Darcy, E (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM eric.c.darcy@nasa.gov NR 1 TC 8 Z9 8 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD DEC 6 PY 2007 VL 174 IS 2 BP 575 EP 578 DI 10.1016/j.jpowsour.2007.06.245 PG 4 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 246PX UT WOS:000252020500040 ER PT J AU Talbot, R Mao, H Scheuer, E Dibb, J Avery, M AF Talbot, R. Mao, H. Scheuer, E. Dibb, J. Avery, M. TI Total depletion of Hg degrees in the upper troposphere-lower stratosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERIC MERCURY; REACTIVE NITROGEN; AEROSOLS; MISSION; BUDGET; OZONE AB Our current understanding of atmospheric mercury lacks fundamental details. Gas phase elemental mercury (Hg degrees) was measured aboard the NASA DC-8 research aircraft during the Intercontinental Chemical Transport Experiment-Phase B (INTEX- B) conducted in spring 2006 over the North Pacific. Our data confirm efficient chemical cycling of Hg degrees in the tropopause region and show that it is strongly anti-correlated with O-3 there, yielding a tropospheric-stratospheric mixing curve of similar to-0.20 ppqv Hg degrees/ppbv O-3. In addition, we found frequent total depletion of Hg degrees in upper tropospheric (8-12 km) air masses impacted by stratospheric influence. When O-3 mixing ratios were > 300 ppbv, Hg degrees was rarely detected. It appears that in the tropopause and stratosphere Hg degrees is oxidized on the order of days followed by heterogeneous transformation to particulate mercury. These processes constitute an effective chemical sink for Hg degrees at the top of the troposphere, which may recycle mercury back to the gas phase as stratospheric aerosols are eventually dispersed into the troposphere. C1 Univ New Hampshire, Climate Change Res Ctr, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. NASA, Langley Res Ctr, Chem Dynam Branch, Hampton, VA 23681 USA. RP Talbot, R (reprint author), Univ New Hampshire, Climate Change Res Ctr, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. EM robert.talbot@unh.edu NR 25 TC 38 Z9 38 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 5 PY 2007 VL 34 IS 23 AR L23804 DI 10.1029/2007GL031366 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 239NI UT WOS:000251524600006 ER PT J AU Lambert, A Read, WG Livesey, NJ Santee, ML Manney, GL Froidevaux, L Wu, DL Schwartz, MJ Pumphrey, HC Jimenez, C Nedoluha, GE Cofield, RE Cuddy, DT Daffer, WH Drouin, BJ Fuller, RA Jarnot, RF Knosp, BW Pickett, HM Perun, VS Snyder, WV Stek, PC Thurstans, RP Wagner, PA Waters, JW Jucks, KW Toon, GC Stachnik, RA Bernath, PF Boone, CD Walker, KA Urban, J Murtagh, D Elkins, JW Atlas, E AF Lambert, A. Read, W. G. Livesey, N. J. Santee, M. L. Manney, G. L. Froidevaux, L. Wu, D. L. Schwartz, M. J. Pumphrey, H. C. Jimenez, C. Nedoluha, G. E. Cofield, R. E. Cuddy, D. T. Daffer, W. H. Drouin, B. J. Fuller, R. A. Jarnot, R. F. Knosp, B. W. Pickett, H. M. Perun, V. S. Snyder, W. V. Stek, P. C. Thurstans, R. P. Wagner, P. A. Waters, J. W. Jucks, K. W. Toon, G. C. Stachnik, R. A. Bernath, P. F. Boone, C. D. Walker, K. A. Urban, J. Murtagh, D. Elkins, J. W. Atlas, E. TI Validation of the Aura Microwave Limb Sounder middle atmosphere water vapor and nitrous oxide measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HALOGEN OCCULTATION EXPERIMENT; EOS MLS; SPECTROMETER; RETRIEVAL; SYSTEM; STRATOSPHERE; INSTRUMENTS; CALIBRATION; SATELLITE; PROFILES C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. New Mexico Inst Min & Technol, Dept Phys, Socorro, NM 87801 USA. Univ Edinburgh, Sch Geosci, Edinburgh, Midlothian, Scotland. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. Chalmers, Dept Radio & Space Sci, S-41296 Gothenburg, Sweden. NOAA, Global Monitoring Div, Earth Syst Res Lab, Boulder, CO USA. Univ Miami, Div Marine & Atmospher Chem, Coral Gables, FL 33124 USA. RP Lambert, A (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RI Bernath, Peter/B-6567-2012; Urban, Jo/F-9172-2010; Atlas, Elliot/J-8171-2015; Schwartz, Michael/F-5172-2016; Wu, Dong/D-5375-2012; Murtagh, Donal/F-8694-2011 OI Bernath, Peter/0000-0002-1255-396X; Urban, Jo/0000-0001-7026-793X; Schwartz, Michael/0000-0001-6169-5094; Murtagh, Donal/0000-0003-1539-3559 NR 50 TC 154 Z9 154 U1 1 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 5 PY 2007 VL 112 IS D24 AR D24S36 DI 10.1029/2007JD008724 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 239OA UT WOS:000251526400001 ER PT J AU Niemann, DL Ribaya, BP Gunther, N Rahman, M Leung, J Nguyen, CV AF Niemann, Darrell L. Ribaya, Bryan P. Gunther, Norman Rahman, Mahmudur Leung, Joseph Nguyen, Cattien V. TI Effects of cathode structure on the field emission properties of individual multi-walled carbon nanotube emitters SO NANOTECHNOLOGY LA English DT Article ID ELECTRON-EMISSION; ENHANCEMENT; PROBE; FILMS; TIP AB We report the effect of cathode structure on the field emission properties of individual carbon nanotubes. Experimental field emission data are obtained for two well-defined cathode structures: a multi-walled carbon nanotube (MWNT) attached to an etched Ni metal wire and a MWNT attached to a flat Ni-coated Si microstructure. We observed different macroscopic turn-on fields of 1.6 and 2.5 V mu m(-1), respectively, for the aforementioned experimental structures. This effect is investigated by detailed finite element analysis. We demonstrate that the geometry of the cathode structures significantly affects the microscopic tip field, leading to different turn-on voltages and field distributions for such individual MWNT emitters. Simulations show that changing the support geometry from a hemispherically capped shank to a cylindrical shank produces an increase in the macroscopic threshold field of 0.91 V mu m(-1). This effect is further investigated by varying the support radius from 0.5 to 30 mu m for a cylindrically shaped support structure. The results show that such a variation in the radius of the support structure produces an increase in the macroscopic turn on field from 0.72 to 5.89 V mu m(-1). We also report quantitative evidence for the nonlinear relationship between the field enhancement factor as a function of support structure radius for nanostructures of three different aspect ratios. C1 Santa Clara Univ, Dept Elect Engn, Electron Devices Lab, Santa Clara, CA 95053 USA. NASA, Ames Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Rahman, M (reprint author), Santa Clara Univ, Dept Elect Engn, Electron Devices Lab, Santa Clara, CA 95053 USA. EM mrahman@scu.edu; cvnguyen@mail.arc.nasa.gov NR 23 TC 16 Z9 16 U1 1 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD DEC 5 PY 2007 VL 18 IS 48 AR 485702 DI 10.1088/0957-4484/18/48/485702 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 228JG UT WOS:000250725600022 ER PT J AU Palinkas, LA Reedy, KR Shepanek, M Smith, M Anghel, M Steel, GD Reeves, D Case, HS Van Do, N Reed, HL AF Palinkas, Lawrence A. Reedy, Kathleen R. Shepanek, Marc Smith, Mark Anghel, Mihai Steel, Gary D. Reeves, Dennis Case, H. Samuel Van Do, Nhan Reed, H. Lester TI Environmental influences on hypothalamic-pituitary-thyroid function and behavior in Antarctica SO PHYSIOLOGY & BEHAVIOR LA English DT Article DE Antarctica; cold; altitude; mood; cognition; human; thermoregulation; thyroid hormones ID SEASONAL AFFECTIVE-DISORDER; GENERAL COLD ADAPTATION; L-THYROXINE TREATMENT; SUBCLINICAL HYPOTHYROIDISM; COGNITIVE PERFORMANCE; STIMULATING HORMONE; HIGH-ALTITUDE; RESIDENCE; TRIIODOTHYRONINE; HUMANS AB We examined the physiological and psychological status of men and women who spent the summer (n=100) and/or winter (n=85) seasons in Antarctica at McMurdo (latitude 78.48 S, elevation 12 in) and South Pole (latitude 90 S, elevation 3880 in) stations to determine whether there were any significant differences by severity of the stations' physical environment. Physiological measures (body mass index, blood pressure, heart rate, tympanic temperature), serum measures of thyroid hormones, cortisol, and lipids and plasma catecholamines were obtained at predeployment (Sep-Oct) and the beginning of the summer (November) and winter (Mar-Apr) seasons. Cognitive performance and mood were assessed using the Automatic Neuropsychological Assessment Metric - Isolated and Confined Environments (ANAM-ICE), a computerized test battery. South Pole residents had a lower body mass index (p<0.05) and body temperature (p<0.01) and higher levels of plasma norepinephrine (p<0.05) in summer and winter than McMurdo residents. Upon deployment from the United States and during the summer, South Pole residents experienced significantly higher thyroid hormone values (free and total T-3 and T-4) (p<0.01) than McMurdo residents; in summer they also experienced lower levels of triglycerides (p<0.01) cortisol (p<0.05) and LDL (p<0.05). In winter, South Pole residents also experienced a 39% decrease in serum TSH compared with a 31.9% increase in McMurdo (p<0.05). South Pole residents also were significantly more accurate (p<0.05) and efficient (p<0.01) in performance of complex cognitive tasks in summer and winter. Higher thyroid hormone levels, combined with lower BMI and body temperature, may reflect increased metabolic and physiological responses to colder temperatures and/or higher altitude at South Pole with no apparent adverse effect on mood and cognition. (C) 2007 Elsevier Inc. All rights reserved. C1 [Palinkas, Lawrence A.] Univ So Calif, Sch Social Work, Los Angeles, CA 90089 USA. [Reedy, Kathleen R.] US FDA, Silver Spring, MD 20993 USA. [Shepanek, Marc] NASA, Washington, DC 20546 USA. [Smith, Mark] George Washington Univ, Dept Psychiat, Washington, DC 20037 USA. [Anghel, Mihai] Univ Calif San Diego, Dept Family & Prevent Med, La Jolla, CA 92093 USA. [Steel, Gary D.] Lincoln Univ, Christchurch, New Zealand. [Reeves, Dennis] Clinvest Inc, Springfield, MO 65807 USA. [Case, H. Samuel] McDaniel Coll, Dept Exercise Sci & Phys Educ, Westminster, MD 21157 USA. [Van Do, Nhan] Madigan Army Med Ctr, Dept Med, Endocrine Serv, Tacoma, WA 98431 USA. [Reed, H. Lester] MultiCare Hlth Syst, Tacoma, WA 98415 USA. RP Palinkas, LA (reprint author), Univ So Calif, Sch Social Work, Los Angeles, CA 90089 USA. EM palinkas@usc.edu NR 45 TC 8 Z9 9 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0031-9384 J9 PHYSIOL BEHAV JI Physiol. Behav. PD DEC 5 PY 2007 VL 92 IS 5 BP 790 EP 799 DI 10.1016/j.physbeh.2007.06.008 PG 10 WC Psychology, Biological; Behavioral Sciences SC Psychology; Behavioral Sciences GA 242BB UT WOS:000251698400002 PM 17628620 ER PT J AU Landis, GA Mellott, KC AF Landis, Geoffrey A. Mellott, Kenneth C. TI Venus surface power and cooling systems SO ACTA ASTRONAUTICA LA English DT Article AB A mission to the surface of Venus would have high scientific value, but most electronic devices and sensors cannot operate at the 450 degrees C ambient surface temperature of Venus. Power and cooling systems were analyzed for Venus surface operation. A radioisotope power and cooling system was designed to provide electrical power for a probe operating on the surface of Venus. For a mission duration of substantial length, the use of thermal mass to maintain an operable temperature range is likely impractical, and active refrigeration may be required to keep components at a temperature below ambient. Due to the high thermal convection of the high-density atmosphere, the heat rejection temperature was assumed to be at a 500 degrees C radiator temperature, 50 degrees C above ambient. The radioisotope Stirling power converter designed produces a thermodynamic power output capacity of 478.1 W, with a cooling power of 100 W. The overall efficiency is calculated to be 23.36%. The mass of the power converter is estimated at approximately 21.6kg. Published by Elsevier Ltd. C1 NASA, John Glenn Res Ctr, Cleveland, OH 44135 USA. RP Landis, GA (reprint author), NASA, John Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM geoffrey.a.landis@nasa.gov NR 25 TC 5 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD DEC PY 2007 VL 61 IS 11-12 BP 995 EP 1001 DI 10.1016/j.actaastro.2006.12.031 PG 7 WC Engineering, Aerospace SC Engineering GA 238RW UT WOS:000251466300004 ER PT J AU Prior, M Dunham, L AF Prior, Michael Dunham, Larry TI System design and performance of the two-gyro science mode for the Hubble Space Telescope SO ACTA ASTRONAUTICA LA English DT Article AB For 15 years, the science mission of the Hubble Space Telescope (HST) required using three of the six on-board rate gyros for attitude control. Failed gyros were eventually replaced through Space Shuttle Servicing Missions. To ensure the maximum science mission life, a two-gyro science (TGS) mode has been designed and implemented with performance comparable to three-gyro operations. The excellent performance has enabled a transition to operations with 2 gyros (by intentionally turning off a running gyro to save it for later use), and allows for an even greater science mission extension. Predictions show the gain in mission life approaching two years. In TGS mode, the rate information formerly provided by the third gyro is provided by another sensor. There are three submodes, each defined by the sensor used to provide the missing rate information (magnetometers, star trackers. and fine guidance sensors). Although each sensor has limitations, when used sequentially they provide the means to transition from relatively large, post-maneuver attitude errors of up to 10 degrees, to the arcsecond errors needed to transition to fine pointing required for science observing. Only small reductions in science productivity exist in TGS mode primarily due to more difficult tar-et scheduling necessary to satisfy constraints imposed by the use of the star trackers. Scientists see no degradation in image quality due to the very low jitters levels that are nearly equivalent to three-gyro mode. Published by Elsevier Ltd. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Vantage Syst Inc, Lanham, MD USA. RP Prior, M (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM mprior@hst.nasa.gov; ldunlham@hst.nasa.gov NR 0 TC 2 Z9 2 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD DEC PY 2007 VL 61 IS 11-12 BP 1010 EP 1018 DI 10.1016/j.actaastro.2006.12.027 PG 9 WC Engineering, Aerospace SC Engineering GA 238RW UT WOS:000251466300006 ER PT J AU Dyke, RE Hrinda, GA AF Dyke, R. Eric Hrinda, Glenn A. TI Aeroshell design techniques for aerocapture entry vehicles SO ACTA ASTRONAUTICA LA English DT Article AB A major goal of NASAs In-Space Propulsion Program is to shorten trip times for scientific planetary missions. To meet this challenge arrival speeds will increase, requiring significant braking for orbit insertion, and thus increased deceleration propellant mass that may exceed launch lift capabilities. A technology called aerocapture has been developed to expand the mission potential of exploratory probes destined for planets with suitable atmospheres. Aerocapture inserts a probe into planetary orbit via a single pass through the atmosphere using the probe's aeroshell drag to reduce velocity. The benefit of an aerocapture maneuver is a large reduction in propellant mass that may result in smaller, less costly missions and reduced mission cruise times. The methodology used to design rigid aerocapture aeroshells will be presented with an emphasis on a new systems tool under development. Current methods for fast, efficient evaluations of structural systems for exploratory vehicles to planets and moons within our solar system have been under development within NASA having limited success. Many systems tools that have been attempted applied structural mass estimation techniques based on historical data and curve fitting techniques that are difficult and cumbersome to apply to new vehicle concepts and missions. The resulting vehicle aeroshell mass may be incorrectly estimated or have high margins included to account for uncertainty. This new tool will reduce the guesswork previously found in conceptual aeroshell mass estimations. Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Swales Aerosp, Hampton, VA 23665 USA. RP Dyke, RE (reprint author), NASA, Langley Res Ctr, Swales Aerosp, Hampton, VA 23665 USA. EM r.e.dyke@larc.nasa.gov; g.a.hrinda@larc.nasa.gov NR 22 TC 1 Z9 1 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD DEC PY 2007 VL 61 IS 11-12 BP 1029 EP 1042 DI 10.1016/j.actaastro.2006.12.037 PG 14 WC Engineering, Aerospace SC Engineering GA 238RW UT WOS:000251466300008 ER PT J AU Pater, RH Curto, PA AF Pater, Ruth H. Curto, Paul A. TI Advanced materials for space applications SO ACTA ASTRONAUTICA LA English DT Article AB Since NASA was created in 1958, over 6400 patents have been issued to the agency-nearly one in a thousand of all patents ever issued in the United States. A large number of these inventions have focused on new materials that have made space travel and exploration of the moon, Mars, and the outer planets possible. In the last few years, the materials developed by NASA Langley Research Center embody breakthroughs in performance and properties that will enable great achievements in space. The examples discussed below offer significant advantages for use in small satellites, i.e., those with payloads under a metric ton. These include patented products such as LaRC SI, LaRC RP 46, LaRC RP 50, PETI-5, TEEK, PETI-330, LaRC CP, TOR-LM and LaRC LCR (patent pending). These and other new advances in nanotechnology engineering, self-assembling nanostructures and multifunctional aerospace materials are presented and discussed below, and applications with significant technological and commercial advantages are proposed. Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA Headquarters, Washington, DC 20546 USA. RP Pater, RH (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM Ruth.H.Pater@nasa.gov; pcurto@hq.nasa.gov NR 2 TC 18 Z9 20 U1 3 U2 19 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD DEC PY 2007 VL 61 IS 11-12 BP 1121 EP 1129 DI 10.1016/j.actaastro.2007.06.002 PG 9 WC Engineering, Aerospace SC Engineering GA 238RW UT WOS:000251466300018 ER PT J AU Jonsson, A Morris, RA Pedersen, L AF Jonsson, Ari Morris, Robert A. Pedersen, Liam TI Autonomy in space current capabilities and future challenges SO AI MAGAZINE LA English DT Article AB This article provides an overview of the nature and role of autonomy for space exploration, with a bias in focus towards describing the relevance of AI technologies. It explores the range of autonomous behavior that is relevant and useful in space exploration and illustrates the range of possible behaviors by presenting four case studies in space-exploration systems, each differing from the others in the degree of autonomy exemplified. Three core requirements are defined for autonomous space systems, and the architectures for integrating capabilities into an autonomous system are described. The article concludes with a discussion of the challenges that are faced currently in developing and deploying autonomy technologies for space. C1 [Jonsson, Ari] Reykjavik Univ, Sch Comp Sci, Reykjavik, Iceland. [Morris, Robert A.] NASA, Ames Res Ctr, Intelligent Syst Div, Washington, DC 20546 USA. [Pedersen, Liam] NASA, Ames Res Ctr, Washington, DC 20546 USA. RP Jonsson, A (reprint author), Reykjavik Univ, Sch Comp Sci, Reykjavik, Iceland. EM pedersen@email.arc.nasa.gov NR 33 TC 5 Z9 5 U1 0 U2 0 PU AMER ASSOC ARTIFICIAL INTELL PI MENLO PK PA 445 BURGESS DRIVE, MENLO PK, CA 94025-3496 USA SN 0738-4602 J9 AI MAG JI AI Mag. PD WIN PY 2007 VL 28 IS 4 BP 27 EP 42 PG 16 WC Computer Science, Artificial Intelligence SC Computer Science GA 244DS UT WOS:000251846800002 ER PT J AU Gupta, KK Bacw, C AF Gupta, K. K. Bacw, C. TI Systems identification approach for a computational-fluid-dynamics-based aeroelastic analysis SO AIAA JOURNAL LA English DT Article AB This paper presents a novel state-space model-based syst ems identification method for accurate and efficient simulation of the aeroelastic phenomenon of flight vehicles, among others. Both structural and fluid discretization are achieved by the common finite element method, their interactions being modeled by the transpiration boundary condition technique. The computational fluid dynamics analysis is valid for either inviscid or viscous flow, and structural deformation is assumed to be small in nature. A number of example problems are solved by the systems identification procedure, developed herein, and such results are compared with that obtained by the direct time-marched analysis method reported earlier. The examples include a cantilever wing with a NACA 0012 airfoil, the Hyper X launch vehicle, and the F/A-18 AAW aircraft. These analysis results show a considerable improvement in central processing unit solution time for the new systems identification procedure over the usual time-marched solution. C1 [Gupta, K. K.; Bacw, C.] NASA, Dryden Flight Res Ctr, Analyt Serv& Mat Inc, Edwards AFB, CA 93523 USA. RP Gupta, KK (reprint author), NASA, Dryden Flight Res Ctr, Analyt Serv& Mat Inc, Edwards AFB, CA 93523 USA. NR 21 TC 8 Z9 9 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 2007 VL 45 IS 12 BP 2820 EP 2827 DI 10.2514/1.28647 PG 8 WC Engineering, Aerospace SC Engineering GA 258CL UT WOS:000252845900002 ER PT J AU Patnaik, SN Pai, SS Hopkins, DA AF Patnaik, Surya N. Pai, Shantaram S. Hopkins, Dale A. TI Compatibility condition in theory of solid mechanics (elasticity, structures, and design optimization) SO ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING LA English DT Review ID INTEGRATED FORCE METHOD; FINITE-ELEMENT ANALYSIS; DISPLACEMENT CONSTRAINTS; STRESS; FORMULATION; FREQUENCY AB The strain formulation in elasticity and the compatibility condition in structural mechanics have neither been understood nor have they been utilized. This shortcoming prevented the formulation of a direct method to calculate stress and strain, which are currently obtained indirectly by differentiating the displacement. We have researched and understood the compatibility condition for linear problems in elasticity and in finite element structural analysis. This has lead to the completion of the "method of force" with stress (or stress resultant) as the primary unknown. The method in elasticity is referred to as the completed Beltrami-Michell formulation (CBMF), and it is the integrated force method (IFM) in the finite element analysis. The dual integrated force method (IFMD) with displacement as the primary unknown had been formulated. Both the IFM and IFMD produce identical responses. The IFMD can utilize the equation solver of the traditional stiffness method. The variational derivation of the CBMF produced the existing sets of elasticity equations along with the new boundary compatibility conditions, which were missed since the time of Saint-Venant, who formulated the field equations about 1860. The CBMF, which can be used to solve stress, displacement, and mixed boundary value problems, has eliminated the restriction of the classical method that was applicable only to stress boundary value problem. The IFM in structures produced high-fidelity response even with a modest finite element model. Because structural design is stress driven, the IFM has influenced it considerably. A fully utilized design method for strength and stiffness limitation was developed via the IFM analysis tool. The method has identified the singularity condition in structural optimization and furnished a strategy that alleviated the limitation and reduced substantially the computation time to reach the optimum solution. The CBMF and IFM tensorial approaches are robust formulations because both methods simultaneously emphasize the equilibrium equation and the compatibility condition. The vectorial displacement method emphasized the equilibrium, while the compatibility condition became the basis of the scalar stress-function approach. The tensorial approach can be transformed to obtain the vector and the scalar methods, but the reverse course cannot be followed. The tensorial approach outperformed other methods as expected. This paper introduces the new concepts in elasticity, in finite element analysis, and in design optimization with numerical illustrations. C1 Ohio Aerosp Inst, Brookpark, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Patnaik, SN (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Brookpark, OH 44142 USA. EM Surya.N.Patnaik@nasa.gov NR 55 TC 1 Z9 1 U1 1 U2 7 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1134-3060 J9 ARCH COMPUT METHOD E JI Arch. Comput. Method Eng. PD DEC PY 2007 VL 14 IS 4 BP 431 EP 457 DI 10.1007/s11831-007-9011-9 PG 27 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Computer Science; Engineering; Mathematics GA 223LX UT WOS:000250373100003 ER PT J AU Hoehler, TM Amend, JP Shock, EL AF Hoehler, Tori M. Amend, Jan P. Shock, Everett L. TI Introduction - A "Follow the energy" approach for astrobiology SO ASTROBIOLOGY LA English DT Editorial Material ID WATER C1 [Hoehler, Tori M.] NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA 94035 USA. [Amend, Jan P.] Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. [Shock, Everett L.] Arizona State Univ, Dept Chem & Biochem, Tempe, AZ 85287 USA. [Shock, Everett L.] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. RP Hoehler, TM (reprint author), NASA, Ames Res Ctr, Exobiol Branch, Mail Stop 239-4, Moffett Field, CA 94035 USA. EM tori.m.hoehler@nasa.gov NR 24 TC 24 Z9 25 U1 2 U2 34 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD DEC PY 2007 VL 7 IS 6 BP 819 EP 823 DI 10.1089/ast.2007.0207 PG 5 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 249YX UT WOS:000252268300001 PM 18069913 ER PT J AU Hoehler, TM AF Hoehler, Tori M. TI An energy balance concept for habitability SO ASTROBIOLOGY LA English DT Article DE habitability; bioenergetics ID ANOXIC MARINE SEDIMENT; MAINTENANCE ENERGY; NITROGEN-FIXATION; TEMPERATURE; GROWTH; LIFE; REQUIREMENTS; SURVIVAL; ARCHAEA; PH AB Habitability can be formulated as a balance between the biological demand for energy and the corresponding potential for meeting that demand by transduction of energy from the environment into biological process. The biological demand for energy is manifest in two requirements, analogous to the voltage and power requirements of an electrical device, which must both be met if life is to be supported. These requirements exhibit discrete (non-zero) minima whose magnitude is set by the biochemistry in question, and they are increased in quantifiable fashion by (i) deviations from biochemically optimal physical and chemical conditions and (ii) energy-expending solutions to problems of resource limitation. The possible rate of energy transduction is constrained by (i) the availability of usable free energy sources in the environment, (ii) limitations on transport of those sources into the cell, (iii) upper limits on the rate at which energy can be stored, transported, and subsequently liberated by biochemical mechanisms (e. g., enzyme saturation effects), and (iv) upper limits imposed by an inability to use "power" and "voltage" at levels that cause material breakdown. A system is habitable when the realized rate of energy transduction equals or exceeds the biological demand for energy. For systems in which water availability is considered a key aspect of habitability (e. g., Mars), the energy balance construct imposes additional, quantitative constraints that may help to prioritize targets in search-for-life missions. Because the biological need for energy is universal, the energy balance construct also helps to constrain habitability in systems (e. g., those envisioned to use solvents other than water) for which little constraint currently exists. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hoehler, TM (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM tori.m.hoehler@nasa.gov NR 44 TC 26 Z9 28 U1 2 U2 27 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD DEC PY 2007 VL 7 IS 6 BP 824 EP 838 DI 10.1089/ast.2006.0095 PG 15 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 249YX UT WOS:000252268300002 PM 18163865 ER PT J AU Vance, S Harnmeijer, J Kimura, J Hussmann, H Demartin, B Brown, JM AF Vance, Steve Harnmeijer, Jelte Kimura, Jun Hussmann, Hauke Demartin, Brian Brown, J. Michael TI Hydrothermal systems in small ocean planets SO ASTROBIOLOGY LA English DT Article DE energy; hydrothermal systems; ocean planets; rock mechanics; tides ID MID-ATLANTIC RIDGE; ULTRAMAFIC ROCKS; VENT FLUIDS; HEAT-FLOW; EXPERIMENTAL CONSTRAINTS; INTERNAL STRUCTURE; TIDAL DISSIPATION; SUBSURFACE OCEANS; UPPER-MANTLE; KUIPER-BELT AB We examine means for driving hydrothermal activity in extraterrestrial oceans on planets and satellites of less than one Earth mass, with implications for sustaining a low level of biological activity over geological timescales. Assuming ocean planets have olivine-dominated lithospheres, a model for cooling-induced thermal cracking shows how variation in planet size and internal thermal energy may drive variation in the dominant type of hydrothermal system-for example, high or low temperature system or chemically driven system. As radiogenic heating diminishes over time, progressive exposure of new rock continues to the current epoch. Where fluid-rock interactions propagate slowly into a deep brittle layer, thermal energy from serpentinization may be the primary cause of hydrothermal activity in small ocean planets. We show that the time-varying hydrostatic head of a tidally forced ice shell may drive hydrothermal fluid flow through the seafloor, which can generate moderate but potentially important heat through viscous interaction with the matrix of porous seafloor rock. Considering all presently known potential ocean planets-Mars, a number of icy satellites, Pluto, and other trans-neptunian objects-and applying Earth-like material properties and cooling rates, we find depths of circulation are more than an order of magnitude greater than in Earth. In Europa and Enceladus, tidal flexing may drive hydrothermal circulation and, in Europa, may generate heat on the same order as present-day radiogenic heat flux at Earth's surface. In all objects, progressive serpentinization generates heat on a globally averaged basis at a fraction of a percent of present-day radiogenic heating and hydrogen is produced at rates between 109 and 1010 molecules cm (-2) s (-1). C1 [Vance, Steve; Harnmeijer, Jelte; Brown, J. Michael] Univ Washington, Dept Earth & Space Sci, Astrobiol Program, Seattle, WA 98195 USA. [Kimura, Jun] Univ Tokyo, Earthquake Res Inst, Tokyo 113, Japan. [Hussmann, Hauke] DLR, Inst Planetary Res, Berlin, Germany. [Demartin, Brian] Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. RP Vance, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM svance@ess.washington.edu RI Kimura, Jun/D-6050-2013 OI Kimura, Jun/0000-0002-5825-0454 NR 97 TC 53 Z9 54 U1 12 U2 50 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD DEC PY 2007 VL 7 IS 6 BP 987 EP 1005 DI 10.1089/ast.2007.0075 PG 19 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 249YX UT WOS:000252268300011 PM 18163874 ER PT J AU Hand, KP Carlson, RW Chyba, CF AF Hand, Kevin P. Carlson, Robert W. Chyba, Christopher F. TI Energy, chemical disequilibrium, and geological constraints on Europa SO ASTROBIOLOGY LA English DT Article DE Europa; radiolysis; oxygen; habitability; planetary science ID PROTON IRRADIATED H2O+CO2; ICY GALILEAN SATELLITES; CARBONIC-ACID; HYDROTHERMAL SYSTEMS; OPTICAL-PROPERTIES; OXYGEN; OCEAN; LIFE; ENCELADUS; SHELL AB Europa is a prime target for astrobiology. The presence of a global subsurface liquid water ocean and a composition likely to contain a suite of biogenic elements make it a compelling world in the search for a second origin of life. Critical to these factors, however, may be the availability of energy for biological processes on Europa. We have examined the production and availability of oxidants and carbon-containing reductants on Europa to better understand the habitability of the subsurface ocean. Data from the Galileo Near-Infrared Mapping Spectrometer were used to constrain the surface abundance of CO2 to 0.036% by number relative to water. Laboratory results indicate that radiolytically processed CO2-rich ices yield CO and H2CO3; the reductants H2CO, CH3OH, and CH4 are at most minor species. We analyzed chemical sources and sinks and concluded that the radiolytically processed surface of Europa could serve to maintain an oxidized ocean even if the surface oxidants (O-2, H2O2, CO2, SO2, and SO42-) are delivered only once every similar to 0.5 Gyr. If delivery periods are comparable to the observed surface age (30-70 Myr), then Europa's ocean could reach O-2 concentrations comparable to those found in terrestrial surface waters, even if similar to 10(9) moles yr(-1) of hydrothermally delivered reductants consume most of the oxidant flux. Such an ocean would be energetically hospitable for terrestrial marine macrofauna. The availability of reductants could be the limiting factor for biologically useful chemical energy on Europa. C1 [Hand, Kevin P.] Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. [Carlson, Robert W.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. [Chyba, Christopher F.] Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. RP Hand, KP (reprint author), Princeton Univ, Dept Astrophys Sci, Peyton Hall, Princeton, NJ 08544 USA. EM khand@stanford.edu NR 72 TC 46 Z9 48 U1 5 U2 37 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD DEC PY 2007 VL 7 IS 6 BP 1006 EP 1022 DI 10.1089/ast.2007.0156 PG 17 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 249YX UT WOS:000252268300012 PM 18163875 ER PT J AU Sahai, R Morris, M Contreras, CS Claussen, M AF Sahai, Raghvendra Morris, Mark Sanchez Contreras, Carmen Claussen, Mark TI Preplanetary nebulae: A Hubble Space Telescope imaging survey and a new morphological classification system SO ASTRONOMICAL JOURNAL LA English DT Article DE circumstellar matter; planetary nebulae : general; stars : AGB and post-AGB; stars : mass loss ID YOUNG PLANETARY-NEBULAE; BIPOLAR PROTOPLANETARY NEBULA; ASYMPTOTIC-GIANT-BRANCH; WATER-MASER EMISSION; OH-1612 MHZ SURVEY; POST-AGB STARS; CIRCUMSTELLAR ENVELOPES; IRAS 19475+3119; OH/IR STARS; H-2 LINE AB Using the Hubble Space Telescope (HST), we have carried out a survey of candidate preplanetary nebulae (PPNs). We report here our discoveries of objects having well-resolved geometric structures, and we use the large sample of PPNs now imaged with HST (including previously studied objects in this class) to devise a comprehensive morphological classification system for this category of objects. The wide variety of aspherical morphologies which we have found for PPNs are qualitatively similar to those found for young planetary nebulae (PNs) in previous surveys. We also find prominent halos surrounding the central aspherical shapes in many of our objects; these are direct signatures of the undisturbed circumstellar envelopes of the progenitor AGB stars. Although the majority of these have surface brightness distributions consistent with a constant mass-loss rate with a constant expansion velocity, there are also examples of objects with varying mass-loss rates. As in our surveys of young PNs, we find no round PPNs. The similarities in morphologies between our survey objects and young PNs supports the view that the former are the progenitors of aspherical PNs. This suggests that the primary shaping of a PN does not occur during the PN phase via the fast radiative wind of the hot central star, but significantly earlier in its evolution. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Inst Estruct Mat, Dept Astrofis Mol & Infraroja, E-28006 Madrid, Spain. Natl Radio Astron Observ, Socorro, NM 87801 USA. RP Sahai, R (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RI Sanchez-Contreras, Carmen/N-3718-2015 OI Sanchez-Contreras, Carmen/0000-0002-6341-592X NR 87 TC 104 Z9 104 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD DEC PY 2007 VL 134 IS 6 BP 2200 EP 2225 DI 10.1086/522944 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235MF UT WOS:000251237600010 ER PT J AU Reipurth, B Guimaraes, MM Connelley, MS Bally, J AF Reipurth, Bo Guimaraes, Marcelo M. Connelley, Michael S. Bally, John TI Visual binaries in the Orion Nebula Cluster SO ASTRONOMICAL JOURNAL LA English DT Article DE binaries : visual; open clusters and associations : individual (Orion Nebula Cluster); stars : low-mass, brown dwarfs; stars : pre-main-sequence; techniques : high angular resolution ID STAR-FORMING REGIONS; MAIN-SEQUENCE STARS; SOLAR-TYPE STARS; LOW-MASS STARS; TRAPEZIUM-CLUSTER; BROWN DWARFS; SPACE-TELESCOPE; WIDE BINARIES; EVOLUTIONARY MODELS; MULTIPLICITY SURVEY AB We have carried out a major survey for visual binaries toward the Orion Nebula Cluster, using images obtained with the Advanced Camera for Surveys on the Hubble Space Telescope through an H alpha filter. From 1051 stars more than 6000 from theta(1) Ori C, we have selected 781 that fulfill the criteria for membership in the Orion Nebula Cluster. Among these, we find 78 multiple systems (75 binaries and 3 triples), of which 55 are new discoveries, in the range from 0.1" to 1.5". We perform a statistical study of the 72 binaries and 3 triples that have separations in the limited range 0.15" to 1.5", within which we need no incompleteness correction. An analysis of the stellar density in our images suggests that of these binaries, nine are line-of-sight associations. When corrected for this, we find a binary fraction of 8.8% +/- 1.1% within the limited separation range from 67.5 to 675 AU ( counting the three triples as six binaries). The field binary fraction in the same range from Duquennoy & Mayor is a factor of 1.5 higher. Within the range 150-675 AU that overlaps the study of binaries in T Tauri associations by Reipurth & Zinnecker, we find that the associations have a factor of 2.2 more binaries than the Orion Nebula Cluster, in approximate agreement with earlier results based on data from the inner Trapezium region with small-number statistics. The binary separation distribution function of the Orion Nebula Cluster shows unusual structure, with a sudden steep decrease in the number of binaries as the separation increases beyond 0.5", corresponding to 225AU. We have measured the ratio of binaries wider than 0.5" to binaries closer than 0.5" as a function of distance from the Trapezium, and we find that this ratio is significantly depressed in the inner region of the Orion Nebula Cluster. The deficit of binaries with larger separations in the central part of the cluster is likely due to dissolution or orbital change of the wider binaries during their passage through the potential well of the inner cluster region. All of our primaries appear to be T Tauri stars, with the exception of one Herbig Ae/Be star, and there are indications that a substantial number of secondaries could be brown dwarfs. C1 Univ Hawaii, Astron Inst, Hilo, HI 96720 USA. Univ Fed Minas Gerais, Dept Fis, BR-30123970 Belo Horizonte, MG, Brazil. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Colorado, CASA, Boulder, CO 80309 USA. RP Reipurth, B (reprint author), Univ Hawaii, Astron Inst, 640 N Aohoku Place, Hilo, HI 96720 USA. EM reipurth@ifa.hawaii.edu RI Guimaraes, Marcelo/H-5897-2012; OI Guimaraes, Marcelo/0000-0002-0517-4507; BALLY, JOHN/0000-0001-8135-6612 NR 69 TC 62 Z9 62 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 2007 VL 134 IS 6 BP 2272 EP 2285 DI 10.1086/523596 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235MF UT WOS:000251237600014 ER PT J AU Jess, DB McAteer, RTJ Mathioudakis, M Keenan, FP Andic, A Bloomfield, DS AF Jess, D. B. McAteer, R. T. J. Mathioudakis, M. Keenan, F. P. Andic, A. Bloomfield, D. S. TI Twisting flux tubes as a cause of micro-flaring activity SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE waves; Sun : activity; Sun : evolution; Sun : flares; Sun : oscillations; Sun : photosphere ID CORONAL LOOP OSCILLATIONS; SOLAR ATMOSPHERE; WAVELET ANALYSIS; H-ALPHA; CHROMOSPHERE; NETWORK; SUN AB High-cadence optical observations of an H-alpha blue-wing bright point near solar AR NOAA 10794 are presented. The data were obtained with the Dunn Solar Telescope at the National Solar Observatory/Sacramento Peak using a newly developed camera system, the RAPID DUAL IMAGER. Wavelet analysis is undertaken to search for intensity-related oscillatory signatures, and periodicities ranging from 15 to 370 s are found with significance levels exceeding 95%. During two separate microflaring events, oscillation sites surrounding the bright point are observed to twist. We relate the twisting of the oscillation sites to the twisting of physical flux tubes, thus giving rise to reconnection phenomena. We derive an average twist velocity of 8.1 km s(-1) and detect a peak in the emitted flux between twist angles of 180 degrees and 230 degrees. C1 Queens Univ Belfast, Astrophys Res Ctr, Sch Math & Phys, Belfast BT7 1NN, Antrim, North Ireland. NASA, Goddard Space Flight Ctr, Solar Phys Lab, Greenbelt, MD 20771 USA. Max Planck Inst Sonnensystemforschung, D-37191 Katlenburg Duhm, Germany. RP Jess, DB (reprint author), Queens Univ Belfast, Astrophys Res Ctr, Sch Math & Phys, Belfast BT7 1NN, Antrim, North Ireland. EM djess01@qub.ac.uk RI McAteer, R. T. James/D-3736-2011; Bloomfield, Shaun/G-5809-2011; OI Bloomfield, Shaun/0000-0002-4183-9895; Jess, David/0000-0002-9155-8039; Andic, Aleksandra/0000-0002-6428-6162 NR 28 TC 15 Z9 15 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2007 VL 476 IS 2 BP 971 EP 977 DI 10.1051/0004-6361:20077916 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 236EE UT WOS:000251285000028 ER PT J AU Goad, MR Tyler, LG Beardmore, AP Evans, PA Rosen, SR Osborne, JP Starling, RLC Marshall, FE Yershov, V Burrows, DN Gehrels, N Roming, PWA Moretti, A Capalbi, M Hill, JE Kennea, J Koch, S Berk, DV AF Goad, M. R. Tyler, L. G. Beardmore, A. P. Evans, P. A. Rosen, S. R. Osborne, J. P. Starling, R. L. C. Marshall, F. E. Yershov, V. Burrows, D. N. Gehrels, N. Roming, P. W. A. Moretti, A. Capalbi, M. Hill, J. E. Kennea, J. Koch, S. Berk, D. Vanden TI Accurate early positions for Swift GRBs: enhancing X-ray positions with UVOT astrometry SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma ray : bursts; astrometry ID ALERT TELESCOPE BAT; MIDEX MISSION; AFTERGLOWS AB The Swift Gamma Ray Burst satellite routinely provides prompt positions for GRBs and their afterglows on timescales of a few hundred seconds. However, with a pointing accuracy of only a few arcminutes, and a systematic uncertainty on the star-tracker solutions to the World Coordinate System of 3-4 arcsec, the precision of the early XRT positions is limited to 3-4 arcsec at best. This is significant because operationally, the XRT detects >95% of all GRBs, while the UVOT detects only the optically brightest bursts, similar to 30% of all bursts detected by BAT; thus early and accurate XRT positions are important because for the majority of bursts they provide the best available information for the initial ground-based follow-up campaigns. Here we describe an autonomous way of producing more accurate prompt XRT positions for GRBs and their afterglows, based on UVOT astrometry and a detailed mapping between the XRT and UVOT detectors. The latter significantly reduces the dominant systematic error - the star-tracker solution to the World Coordinate System. This technique, which is limited to times when there is significant overlap between UVOT and XRT PC-mode data, provides a factor of 2 improvement in the localisation of XRT refined positions on timescales of less than a few hours. Furthermore, the accuracy achieved is superior to astrometrically corrected XRT PC mode images at early times ( for up to 24 h), for the majority of bursts, and is comparable to the accuracy achieved by astrometrically corrected X-ray positions based on deep XRT PC-mode imaging at later times. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. UCL, Mullard Space Sci Lab, Dept Space & Climate Phys, Dorking RH5 6NT, Surrey, England. Penn State Univ, University Pk, PA 16802 USA. Osserv Astron Brera, INAF, I-23807 Merate, Italy. ASI Sci Data Ctr, I-00044 Frascati, Italy. Univ Space Res Assoc, Columbia, MD 21044 USA. RP Goad, MR (reprint author), Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. EM mrg@star.le.ac.uk RI Gehrels, Neil/D-2971-2012; OI moretti, alberto/0000-0002-9770-0315 NR 17 TC 54 Z9 54 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2007 VL 476 IS 3 BP 1401 EP 1409 DI 10.1051/0004-6361:20078436 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 239GT UT WOS:000251507500033 ER PT J AU Beckmann, V Barthelmy, SD Courvoisier, TJL Gehrels, N Soldi, S Tueller, J Wendt, G AF Beckmann, V. Barthelmy, S. D. Courvoisier, T. J. -L. Gehrels, N. Soldi, S. Tueller, J. Wendt, G. TI Hard X-ray variability of active galactic nuclei SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : active; galaxies : Seyfert; X-rays : galaxies; surveys ID XMM-NEWTON OBSERVATIONS; SEYFERT-1 GALAXIES; TIME VARIABILITY; AGN VARIABILITY; COMPLETE SAMPLE; BL LACERTAE; HOLE; SPECTROSCOPY; ABSORPTION; EMISSION AB Aims. Active Galactic Nuclei are known to be variable throughout the electromagnetic spectrum. An energy domain poorly studied in this respect is the hard X- ray range above 20 keV. Methods. The first 9 months of the Swift/ BAT all-sky survey are used to study the 14-195 keV variability of the 44 brightest AGN. The sources have been selected due to their detection significance of > 10 sigma. We tested the variability using a maximum likelihood estimator and by analysing the structure function. Results. Probing different time scales, it appears that the absorbed AGN are more variable than the unabsorbed ones. The same applies for the comparison of Seyfert 2 and Seyfert 1 objects. As expected the blazars show stronger variability. 15% of the non- blazar AGN show variability of > 20% compared to the average flux on time scales of 20 days, and 30% show at least 10% flux variation. All the non- blazar AGN which show strong variability are low-luminosity objects with L(14-195 keV) < 10(44) erg s(-1) Conclusions. Concerning the variability pattern, there is a tendency of unabsorbed or type 1 galaxies being less variable than the absorbed or type 2 objects at hardest X- rays. A more solid anti-correlation is found between variability and luminosity, which has been previously observed in soft X- rays, in the UV, and in the optical domain. C1 INTEGRAL Sci Data Ctr, CH-1290 Versoix, Switzerland. Univ Geneva, CH-1290 Sauverny, Switzerland. Univ Maryland Baltimore Cty, CSST, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. RP Beckmann, V (reprint author), INTEGRAL Sci Data Ctr, Chemin Decogia 16, CH-1290 Versoix, Switzerland. EM Volker.Beckmann@obs.unige.ch RI Barthelmy, Scott/D-2943-2012; Gehrels, Neil/D-2971-2012; Tueller, Jack/D-5334-2012 NR 52 TC 22 Z9 22 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2007 VL 475 IS 3 BP 827 EP 835 DI 10.1051/0004-6361:20078355 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231KO UT WOS:000250945900007 ER PT J AU Absil, O du Foresto, VC Barillot, M Swain, MR AF Absil, O. du Foresto, V. Coude Barillot, M. Swain, M. R. TI Nulling interferometry: performance comparison between Antarctica and other ground-based sites SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE atmospheric effects; instrumentation : high angular resolution; techniques : interferometric; circumstellar matter ID MAIN-SEQUENCE STARS; SOUTH-POLE; DOME-C; WATER-VAPOR; PLATEAU; FLUCTUATIONS; ATMOSPHERE; TURBULENCE; PLANETS; GENIE AB Context. Detecting the presence of circumstellar dust around nearby solar-type main sequence stars is an important pre-requisite for the design of future life-finding space missions such as ESA's Darwin or NASA's Terrestrial Planet Finder (TPF). The high Antarctic plateau may provide appropriate conditions to perform such a survey from the ground. Aims. We investigate the performance of a nulling interferometer optimised for the detection of exozodiacal discs at Dome C, on the high Antarctic plateau, and compare it to the expected performance of similar instruments at temperate sites. Methods. Based on the currently available measurements of the atmospheric turbulence characteristics at Dome C, we adapt the GENIEsim software (Absil et al. 2006, A& A, 448, 787) to simulate the performance of a nulling interferometer on the high Antarctic plateau. To feed a realistic instrumental configuration into the simulator, we propose a conceptual design for ALADDIN, the Antarctic L-band Astrophysics Discovery Demonstrator for Interferometric Nulling. We assume that this instrument can be placed above the 30-m thick boundary layer, where most of the atmospheric turbulence originates. Results. We show that an optimised nulling interferometer operating on a pair of 1-m class telescopes located 30 m above the ground could achieve a better sensitivity than a similar instrument working with two 8-m class telescopes at a temperate site such as Cerro Paranal. The detection of circumstellar discs about 20 times as dense as our local zodiacal cloud seems within reach for typical Darwin/TPF targets in an integration time of a few hours. Moreover, the exceptional turbulence conditions significantly relax the requirements on real-time control loops, which has favourable consequences on the feasibility of the nulling instrument. Conclusions. The perspectives for high dynamic range, high angular resolution infrared astronomy on the high Antarctic plateau look very promising. C1 Univ Grenoble 1, LAOG, CNRS, F-38400 Grenoble, France. Univ Liege, Inst Astrophys & Geophys, B-4000 Liege, Belgium. Observ Paris, CNRS, LESIA, F-92195 Meudon, France. Thales Alenia Space, F-06156 Cannes La Bocca, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Absil, O (reprint author), Univ Grenoble 1, LAOG, CNRS, 414 Rue Piscine, F-38400 Grenoble, France. EM olivier.absil@obs.ujf-grenoble.fr OI Absil, Olivier/0000-0002-4006-6237 NR 35 TC 11 Z9 11 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2007 VL 475 IS 3 BP 1185 EP 1194 DI 10.1051/0004-6361:20077582 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231KO UT WOS:000250945900040 ER PT J AU Bland, PA Kearsley, AT Wozniakiewicz, PJ Burchell, MJ Gounelle, M Zolensky, ME Genge, MJ AF Bland, Phil A. Kearsley, Anton T. Wozniakiewicz, P. J. Burchell, M. J. Gounelle, M. Zolensky, M. E. Genge, Matt J. TI A comet in the lab SO ASTRONOMY & GEOPHYSICS LA English DT Article ID STARDUST; 81P/WILD-2; CHONDRITES; ORGUEIL AB The Stardust sample-return mission has provided researchers with a glimpse of conditions in the early solar system, in the form of cometary dust with a surprising range of compositions. Some grains arose in the hot inner solar system, others in the cooler outer reaches where comets accrete. There are also grains that formed before the Sun itself. In all, the samples so far have raised as many questions as they have answered, but together they suggest that the early solar system was probably a more complex place than had been supposed. C1 [Bland, Phil A.] Univ London Imperial Coll Sci Technol & Med, Dept Earth Sci & Engn, IARC, London SW7 2AZ, England. [Bland, Phil A.] Nat Hist Museum, IARC, Dept Mineral, London SW7 5BD, England. [Kearsley, Anton T.] IARC NMH, Lyon, France. [Wozniakiewicz, P. J.; Genge, Matt J.] IARC Imperial Coll, Lyon, France. [Wozniakiewicz, P. J.; Genge, Matt J.] Univ Kent, Ctr Astrophys & Planetary Sci, Canterbury, Kent, England. [Burchell, M. J.] Museum Natl Hist Nat, LEME, F-75231 Paris, France. [Gounelle, M.] NASA, Lyndon B Johnson Space Ctr, ARES, Houston, TX 77058 USA. RP Bland, PA (reprint author), Univ London Imperial Coll Sci Technol & Med, Dept Earth Sci & Engn, IARC, London SW7 2AZ, England. NR 24 TC 0 Z9 0 U1 1 U2 3 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1366-8781 J9 ASTRON GEOPHYS JI Astron. Geophys. PD DEC PY 2007 VL 48 IS 6 BP 27 EP 31 PG 5 WC Astronomy & Astrophysics; Geochemistry & Geophysics SC Astronomy & Astrophysics; Geochemistry & Geophysics GA 241GU UT WOS:000251645700021 ER PT J AU Atwood, WB Bagagli, R Baldini, L Bellazzini, R Barbiellini, G Belli, F Borden, T Brez, A Brigida, M Caliandro, GA Cecchi, C Cohen-Tanugi, J De Angelis, A Drell, P Favuzzi, C Fukazawa, Y Fusco, P Gargano, F Germani, S Giannitrapani, R Giglietto, N Giordano, F Himel, T Hirayama, M Johnson, RP Katagiri, H Kataoka, J Kawai, N Kroeger, W Kuss, M Latronico, L Longo, F Loparco, F Lubrano, P Massai, MM Mazziotta, MN Minuti, M Mizuno, T Morselli, A Nelson, D Nordby, M Ohsugi, T Omodei, N Ozaki, M Pepe, M Raino, S Rando, R Razzano, M Rich, D Sadrozinski, HFW Scolieri, G Sgro, C Spandre, G Spinelli, P Sugizaki, M Tajima, H Takahashi, H Takahashi, T Yoshida, S Young, C Ziegler, M AF Atwood, W. B. Bagagli, R. Baldini, L. Bellazzini, R. Barbiellini, G. Belli, F. Borden, T. Brez, A. Brigida, M. Caliandro, G. A. Cecchi, C. Cohen-Tanugi, J. De Angelis, A. Drell, P. Favuzzi, C. Fukazawa, Y. Fusco, P. Gargano, F. Germani, S. Giannitrapani, R. Giglietto, N. Giordano, F. Himel, T. Hirayama, M. Johnson, R. P. Katagiri, H. Kataoka, J. Kawai, N. Kroeger, W. Kuss, M. Latronico, L. Longo, F. Loparco, F. Lubrano, P. Massai, M. M. Mazziotta, M. N. Minuti, M. Mizuno, T. Morselli, A. Nelson, D. Nordby, M. Ohsugi, T. Omodei, N. Ozaki, M. Pepe, M. Raino, S. Rando, R. Razzano, M. Rich, D. Sadrozinski, H. F. -W. Scolieri, G. Sgro, C. Spandre, G. Spinelli, P. Sugizaki, M. Tajima, H. Takahashi, H. Takahashi, T. Yoshida, S. Young, C. Ziegler, M. TI Design and initial tests of the Tracker-converter of the Gamma-ray Large Area Space Telescope SO ASTROPARTICLE PHYSICS LA English DT Article DE gamma-ray; telescope; tracking ID SILICON TRACKER; READOUT ELECTRONICS; ENGINEERING MODEL; BEAM TEST; GLAST; DETECTOR AB The Tracker subsystem of the Large Area Telescope (LAT) science instrument of the Gamma-ray Large Area Space Telescope (GLAST) mission has been completed and tested. It is the central detector subsystem of the LAT and serves both to convert an incident gamma-ray into an electron-positron pair and to track the pair in order to measure the gamma-ray direction. It also provides the principal trigger for the LAT. The Tracker uses silicon strip detectors, read out by custom electronics, to detect charged particles. The detectors and electronics are packaged, along with tungsten converter foils, in 16 modular, high-precision carbon-composite structures. It is the largest silicon-strip detector system ever built for launch into space, and its aggressive design emphasizes very low power consumption, passive cooling, low noise, high efficiency, minimal dead area, and a structure that is highly transparent to charged particles. The test program has demonstrated that the system meets or surpasses all of its performance specifications as well as environmental requirements. It is now installed in the completed LAT, which is being prepared for launch in early 2008. (c) 2007 Elsevier B.V. All rights reserved. C1 [Atwood, W. B.; Johnson, R. P.; Sadrozinski, H. F. -W.; Ziegler, M.] Univ Calif Santa Cruz, Inst Particle Phys, Santa Cruz, CA 95064 USA. [Bagagli, R.; Baldini, L.; Bellazzini, R.; Brez, A.; Kuss, M.; Latronico, L.; Massai, M. M.; Minuti, M.; Razzano, M.; Sgro, C.; Spandre, G.] Univ Pisa, Inst Nazl Fis Nucl, Dipartimento Fis, I-56127 Pisa, Italy. [Barbiellini, G.; De Angelis, A.; Giannitrapani, R.; Longo, F.] Ist Nazl Fis Nucl, Sez Trieste, I-34012 Trieste, Italy. [Belli, F.; Morselli, A.] Ist Nazl Fis Nucl, Sez Roma Tor Vergata, I-00133 Rome, Italy. [Borden, T.; Cohen-Tanugi, J.; Drell, P.; Himel, T.; Kroeger, W.; Nelson, D.; Nordby, M.; Rich, D.; Sugizaki, M.; Tajima, H.; Young, C.] Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. [Caliandro, G. A.; Favuzzi, C.; Fusco, P.; Giglietto, N.; Giordano, F.; Loparco, F.; Mazziotta, M. N.; Raino, S.; Spinelli, P.] Univ Bari, Ist Nazl Fis Nucl, Dipartimento Fis, I-70126 Bari, Italy. [Cecchi, C.; Germani, S.; Lubrano, P.; Pepe, M.; Scolieri, G.] Univ Perugia, Ist Nazl Fis Nucl, Dipartimento Fis, I-06123 Perugia, Italy. [De Angelis, A.; Giannitrapani, R.] Univ Udine, I-33100 Udine, Italy. [Fukazawa, Y.; Katagiri, H.; Mizuno, T.; Ohsugi, T.; Takahashi, H.; Yoshida, S.] Hiroshima Univ, Higashihiroshima 7398526, Japan. [Hirayama, M.] NASA, Goddard Space Flight Ctr, CRESST, Astroparticle Phys Lab, Greenbelt, MD 20771 USA. [Hirayama, M.] Univ Maryland, Dept Phys, Baltimore, MD 21250 USA. [Kataoka, J.; Kawai, N.] Tokyo Inst Technol, Tokyo 1528551, Japan. [Ozaki, M.; Takahashi, T.] ISAS, JAX, Kanagawa 2298510, Japan. [Rando, R.] Univ Padua, Ist Nazl Fis Nucl, Dipartimento Fis, I-35131 Padua, Italy. [Sgro, C.] Scuola Normale Super Pisa, I-56126 Pisa, Italy. RP Johnson, RP (reprint author), Univ Calif Santa Cruz, Inst Particle Phys, 1156 High St, Santa Cruz, CA 95064 USA. EM rjohnson@scipp.ucsc.edu RI Sgro, Carmelo/K-3395-2016; De Angelis, Alessandro/B-5372-2009; Baldini, Luca/E-5396-2012; lubrano, pasquale/F-7269-2012; Morselli, Aldo/G-6769-2011; Kuss, Michael/H-8959-2012; giglietto, nicola/I-8951-2012; Ozaki, Masanobu/K-1165-2013; Rando, Riccardo/M-7179-2013; Loparco, Francesco/O-8847-2015; Gargano, Fabio/O-8934-2015; Mazziotta, Mario /O-8867-2015 OI SPINELLI, Paolo/0000-0001-6688-8864; De Angelis, Alessandro/0000-0002-3288-2517; Omodei, Nicola/0000-0002-5448-7577; Baldini, Luca/0000-0002-9785-7726; lubrano, pasquale/0000-0003-0221-4806; Morselli, Aldo/0000-0002-7704-9553; giglietto, nicola/0000-0002-9021-2888; Loparco, Francesco/0000-0002-1173-5673; Rando, Riccardo/0000-0001-6992-818X; Sgro', Carmelo/0000-0001-5676-6214; Gargano, Fabio/0000-0002-5055-6395; Mazziotta, Mario /0000-0001-9325-4672 NR 16 TC 26 Z9 26 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 J9 ASTROPART PHYS JI Astropart Phys. PD DEC PY 2007 VL 28 IS 4-5 BP 422 EP 434 DI 10.1016/j.astropartphys.2007.08.010 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 244AY UT WOS:000251839600005 ER PT J AU Braito, V Reeves, JN Dewangan, GC George, I Griffiths, RE Markowitz, A Nandra, K Porquet, D Ptak, A Turner, TJ Yaqoob, T Weaver, K AF Braito, V. Reeves, J. N. Dewangan, G. C. George, I. Griffiths, R. E. Markowitz, A. Nandra, K. Porquet, D. Ptak, A. Turner, T. J. Yaqoob, T. Weaver, K. TI Relativistic iron K emission and absorption in the seyfert 1.9 galaxy MCG-5-23-16 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (MCG-5-23-16); galaxies : Seyfert; X-rays : galaxies ID X-RAY-SPECTRUM; ACTIVE GALACTIC NUCLEI; XMM-NEWTON OBSERVATION; REFLECTION GRATING SPECTROMETER; DRIVEN DISK WINDS; BLACK-HOLE; COMPTON REFLECTION; BEPPOSAX OBSERVATIONS; LIKELIHOOD RATIO; ALPHA-EMISSION AB We present the results of the simultaneous deep XMM-Newton and Chandra observations of the bright Seyfert 1.9 galaxy MCG - 5-23-16, which is thought to have one of the best known examples of a relativistically broadened iron K alpha line. The time-averaged spectral analysis shows that the iron K-shell complex is best modeled with an unresolved narrow emission component (FWHM < 5000 km s(-1), EW similar to 60 eV) plus a broad component. This latter component has FWHM similar to 44,000 kms(-1) and EW similar to 50 eV. Its profile is well described by an emission line originating from an accretion disk viewed with an inclination angle similar to 40 degrees, with the emission arising from within a few tens of gravitational radii of the central black hole. The time-resolved spectral analysis of the XMM-Newton EPIC pn spectrum shows that both the narrow and broad components of the Fe K emission line appear to be constant in time within the errors. We detected a narrow sporadic absorption line at 7.7 keV, which appears to be variable on a timescale of 20 ks. If associated with Fe XXVI Ly alpha, this absorption is indicative of a possibly variable, high-ionization, high-velocity outflow. The variability of this absorption feature appears to rule out a local (z = 0) origin. The analysis of the XMM-Newton RGS spectrum reveals that the soft X-ray emission of MCG - 5-23-16 is likely dominated by several emission lines superimposed on an unabsorbed scattered power-law continuum. The lack of strong Fe L-shell emission, together with the detection of a strong forbidden line in the O VII triplet, is consistent with a scenario in which the soft X-ray emission lines are produced in a plasma photoionized by the nuclear emission. C1 NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Keele Univ, Sch Phys & Geog Sci, Keele ST5 5BG, Staffs, England. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. Imperial Coll London, Astrophys Grp, Blackett Lab, London SW72AW, England. CNRS, Astron Observ, UMR 7550, F-67000 Strasbourg, France. RP Braito, V (reprint author), NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Code 662, Greenbelt, MD 20771 USA. EM vale@milkyway.gsfc.nasa.gov RI Ptak, Andrew/D-3574-2012; OI Porquet, Delphine/0000-0001-9731-0352; Braito, Valentina/0000-0002-2629-4989 NR 73 TC 56 Z9 56 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2007 VL 670 IS 2 BP 978 EP 991 DI 10.1086/521916 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235ML UT WOS:000251238300007 ER PT J AU Simpson, JP Colgan, SWJ Cotera, AS Erickson, EF Hollenbach, DJ Kaufman, MJ Rubin, RH AF Simpson, Janet P. Colgan, Sean W. J. Cotera, Angela S. Erickson, Edwin F. Hollenbach, David J. Kaufman, Michael J. Rubin, Robert H. TI Spitzer IRS observations of the galactic center: Shocked gas in the radio arc bubble SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxy : center; HII regions; infrared : ISM; ISM : abundances; ISM : bubbles ID FINE-STRUCTURE LINES; H-II REGIONS; ELECTRON-IMPACT EXCITATION; EFFECTIVE COLLISION STRENGTHS; DIFFUSE INTERSTELLAR-MEDIUM; ELEMENTAL ABUNDANCE RATIOS; LARGE-MAGELLANIC-CLOUD; WOLF-RAYET BUBBLES; TRANSITION-PROBABILITIES; IRON PROJECT AB We present Spitzer IRS spectra ( R similar to 600, 10-38 mu m) of 38 positions in the Galactic center, all at the same Galactic longitude and spanning +/- 0.3 degrees in latitude. Our positions include the Arches Cluster, the Arched Filaments, regions near the Quintuplet Cluster, the "Bubble" lying along the same line of sight as the molecular cloud G0.11-0.11, and the diffuse interstellar gas along the line of sight at higher Galactic latitudes. From measurements of the [O IV], [Ne II], [Ne III], [Si II], [S III], [S IV], [Fe II], [Fe III], and H-2 S(0), S(1), and S(2) lines, we determine the gas excitation and ionic abundance ratios. The Ne/H and S/H abundance ratios are similar to 1.6 times that of the Orion Nebula. The main source of excitation is photoionization, with the Arches Cluster ionizing the Arched Filaments and the Quintuplet Cluster ionizing the gas nearby and at lower Galactic latitudes including the far side of the Bubble. In addition, strong shocks ionize gas to O+3 and destroy dust grains, releasing iron into the gas phase (Fe/H similar to 1.3 x 10(-6) in the Arched Filaments and Fe/H similar to 8.8 x 10(-6) in the Bubble). The shock effects are particularly noticeable in the center of the Bubble, but O+3 is present in all positions. We suggest that the shocks are due to the winds from the Quintuplet Cluster Wolf-Rayet stars. On the other hand, the H-2 line ratios can be explained with multicomponent models of warm molecular gas in photodissociation regions without the need for H-2 production in shocks. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA 94043 USA. San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. RP Simpson, JP (reprint author), NASA, Ames Res Ctr, Mail Stop 245-6,Moffet Field, Moffett Field, CA 94035 USA. RI Colgan, Sean/M-4742-2014 NR 111 TC 24 Z9 24 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2007 VL 670 IS 2 BP 1115 EP 1131 DI 10.1086/522295 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235ML UT WOS:000251238300018 ER PT J AU Akeson, RL Rice, WKM Boden, AF Sargent, AI Carpenter, JM Bryden, G AF Akeson, R. L. Rice, W. K. M. Boden, A. F. Sargent, A. I. Carpenter, J. M. Bryden, G. TI The circumbinary disk of HD 98800B: Evidence for disk warping SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : spectroscopic; circumstellar matter; stars : formation; stars : individual (HD 98800B) ID T-TAURI STARS; SPECTRAL ENERGY-DISTRIBUTIONS; MAIN-SEQUENCE STARS; CIRCUMSTELLAR DISK; DEBRIS DISKS; SPECTROSCOPIC BINARIES; SYSTEM HD-98800; ACCRETION; CONSTRAINTS; PLANETS AB The quadruple young stellar system HD 98800 consists of two spectroscopic binary pairs with a circumbinary disk around the B component. Recent work by Boden and collaborators using infrared interferometry and radial velocity data resulted in a determination of the physical orbit for HD 98800B. We use the resulting inclination of the binary and the measured extinction toward the B component stars to constrain the distribution of circumbinary material. Although a standard optically and geometrically thick disk model can reproduce the spectral energy distribution, it cannot account for the observed extinction if the binary and the disk are coplanar. We next constructed a dynamical model to investigate the influence of the A component, which is not in the Ba-Bb orbital plane, on the B disk. We find that these interactions have a substantial impact on the inclination of the B circumbinary disk with respect to the Ba-Bb orbital plane. The resulting warp would be sufficient to place material into the line of sight and the noncoplanar disk orientation may also cause the upper layers of the disk to intersect the line of sight if the disk is geometrically thick. These simulations also support that the dynamics of the Ba-Bb orbit clear the inner region to a radius of similar to 3 AU. We then discuss whether the somewhat unusual properties of the HD 98800B disk are consistent with material remnant from the star formation process or with more recent creation by collisions from larger bodies. C1 CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. Univ Edinburgh, Scottish Univ Phys Alliance, Astron Inst, Edinburgh EH9 3HJ, Midlothian, Scotland. CALTECH, Dept Astron, Pasadena, CA 91125 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91108 USA. RP Akeson, RL (reprint author), CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. RI Rice, Ken/H-5084-2011 OI Rice, Ken/0000-0002-6379-9185 NR 46 TC 19 Z9 19 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2007 VL 670 IS 2 BP 1240 EP 1246 DI 10.1086/522579 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235ML UT WOS:000251238300031 ER PT J AU Wisniewski, JP Bjorkman, KS Bjorkman, JE Clampin, M AF Wisniewski, John P. Bjorkman, Karen S. Bjorkman, Jon E. Clampin, Mark TI Discovery of a new dusty B[e] star in the small magellanic cloud SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; Magellanic Clouds; stars : individual (NGC 346 : KWBBe 200) stars : individual ([MA93] 1116); stars : emission-line, Be ID B SUPERGIANTS; SPACE-TELESCOPE; MILKY-WAY; P-CYGNI; WIND; LMC; ULTRAVIOLET; EXTINCTION; CANDIDATE; SMC AB We present new optical spectroscopic and archival Spitzer IRAC photometric observations of a B-type star in the SMC cluster NGC 346, NGC 346: KWBBe 200. We detect numerous Fe II, [O I], and [Fe II] lines, as well as strong P Cygni profile H I emission lines in its optical spectrum. The star's near-IR color and optical to IR spectral energy distribution clearly indicate the presence of an infrared excess, consistent with the presence of gas and warm, T similar to 800 K, circumstellar dust. Based on a crude estimate of the star's luminosity and the observed spectroscopic line profile morphologies, we find that the star is likely to be a B-type supergiant. We suggest that NGC 346: KWBBe 200 is a newly discovered B[e] supergiant star, and represents the fifth such object to be identified in the SMC. C1 NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA. RP Wisniewski, JP (reprint author), NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Code 667, Greenbelt, MD 20771 USA. EM john.p.wisniewski@nasa.gov; jon.bjorkman@utoledo.edu; mark.clampin@nasa.gov RI Clampin, mark/D-2738-2012 NR 41 TC 10 Z9 10 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2007 VL 670 IS 2 BP 1331 EP 1336 DI 10.1086/522330 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235ML UT WOS:000251238300042 ER PT J AU De Troia, G Ade, PAR Bock, JJ Bond, JR Borrill, J Boscaleri, A Cabella, P Contaldi, CR Crill, BP de Bernardis, P De Gasperis, G de Oliveira-Costa, A Di Stefano, G Ferreira, PG Hivon, E Jaffe, AH Kisner, TS Kunz, M Jones, WC Lange, AE Liguori, M Masi, S Matarrese, S Mauskopf, PD MacTavish, CJ Melchiorri, A Montroy, TE Natoli, P Netterfield, CB Pascale, E Piacentini, F Pogosyan, D Polenta, G Prunet, S Ricciardi, S Romeo, G Ruhl, JE Santini, P Tegmark, M Veneziani, M Vittorio, N AF De Troia, G. Ade, P. A. R. Bock, J. J. Bond, J. R. Borrill, J. Boscaleri, A. Cabella, P. Contaldi, C. R. Crill, B. P. de Bernardis, P. De Gasperis, G. de Oliveira-Costa, A. Di Stefano, G. Ferreira, P. G. Hivon, E. Jaffe, A. H. Kisner, T. S. Kunz, M. Jones, W. C. Lange, A. E. Liguori, M. Masi, S. Matarrese, S. Mauskopf, P. D. MacTavish, C. J. Melchiorri, A. Montroy, T. E. Natoli, P. Netterfield, C. B. Pascale, E. Piacentini, F. Pogosyan, D. Polenta, G. Prunet, S. Ricciardi, S. Romeo, G. Ruhl, J. E. Santini, P. Tegmark, M. Veneziani, M. Vittorio, N. TI Searching for non-Gaussian signals in the BOOMERANG 2003 CMB maps SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background ID MICROWAVE-ANISOTROPY-PROBE; WMAP OBSERVATIONS; MAKING ALGORITHM; POWER SPECTRUM; FLIGHT; BISPECTRUM; TESTS AB We analyze the BOOMERANG 2003 ( B03) 145 GHz temperature map to constrain the amplitude of a non-Gaussian, primordial contribution to CMB fluctuations. We perform a pixel-space analysis restricted to a portion of the map chosen in view of high-sensitivity, very low foreground contamination and tight control of systematic effects. We set up an estimator based on the three Minkowski functionals which relies on high-quality simulated data, including non-Gaussian CMB maps. We find good agreement with the Gaussian hypothesis and derive the first limits based on BOOMERANG data for the nonlinear coupling parameter as at f(NL) as -300 < f(NL) < 650 at 68% CL and -800 < f(NL) < 1050 at 95% CL. C1 Univ Roma Tor Vergata, Dept Fis, Rome, Italy. Univ Roma La Sapienza, Dept Fis, Rome, Italy. Cardiff Univ, Dept Phys & Astron, Cardiff CF24 3YB, Wales. Jet Propuls Lab, Pasadena, CA USA. CALTECH, Observ Cosmol, Pasadena, CA USA. Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON, Canada. Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. IFAC, CNR, Florence, Italy. Univ Oxford, Oxford OX1 3RH, England. Imperial Coll London, Theoret Phys Grp, London, England. CALTECH, IPAC, Pasadena, CA 91125 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Ist Nazl Geofis Vulcanol, Rome, Italy. Inst Astrophys, F-75014 Paris, France. Univ Geneva, Dept Appl Math & Theoret Phys, CH-1211 Geneva 4, Switzerland. Univ Cambridge, Dept Appl Math & Theoret Phys, Cambridge CB2 1TN, England. Univ Padua, Ist Nazl Fis Nucl, Dipartimento Fis G Galilei, Sez Padova, Padua, Italy. Ist Nazl Fis Nucl, Sez Rome 1, Rome, Italy. Sierra Lobo Inc, Milan, OH 44846 USA. Ist Nazl Fis Nucl, Sez Tor Vergata, Rome, Italy. Univ Toronto, Dept Phys, Toronto, ON, Canada. Univ Alberta, Dept Phys, Edmonton, AB T6G 2M7, Canada. INAF, Osservatorio Astron Padova, Padua, Italy. Case Western Reserve Univ, Dept Phys, Cleveland, OH 44106 USA. APC, F-75205 Paris, France. RP De Troia, G (reprint author), Univ Roma Tor Vergata, Dept Fis, Rome, Italy. RI Jaffe, Andrew/D-3526-2009; de Gasperis, Giancarlo/C-8534-2012; Piacentini, Francesco/E-7234-2010; OI Melchiorri, Alessandro/0000-0001-5326-6003; Hivon, Eric/0000-0003-1880-2733; Matarrese, Sabino/0000-0002-2573-1243; de Gasperis, Giancarlo/0000-0003-2899-2171; Piacentini, Francesco/0000-0002-5444-9327; Ricciardi, Sara/0000-0002-3807-4043; Santini, Paola/0000-0002-9334-8705; Masi, Silvia/0000-0001-5105-1439; de Bernardis, Paolo/0000-0001-6547-6446; ROMEO, Giovanni/0000-0002-5535-7803; Polenta, Gianluca/0000-0003-4067-9196 NR 27 TC 18 Z9 18 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2007 VL 670 IS 2 BP L73 EP L76 DI 10.1086/524402 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235MN UT WOS:000251238500001 ER PT J AU Newman, SF Buratti, BJ Jaumann, R Bauer, JM Momary, TW AF Newman, S. F. Buratti, B. J. Jaumann, R. Bauer, J. M. Momary, T. W. TI Hydrogen peroxide on Enceladus SO ASTROPHYSICAL JOURNAL LA English DT Article DE planets and satellites : individual (Saturn) ID WATER ICE; ION IRRADIATION; SATURN; EUROPA; MAGNETOSPHERE; SPECTROMETER; SATELLITES; SURFACE; PLUME; H2O2 AB Scientists have recently discovered a dynamic, geologically active world in Saturn's icy moon, Enceladus. This small satellite has a south polar hot spot at least 70 K hotter than surrounding regions and a plume of water vapor and ice particles surging from the "tiger stripe" cracks that flank the pole. Spectral data of the surface of Enceladus can help us understand the processes occurring on and beneath the surface and in the regional south polar atmosphere. Using observations from Cassini's Visual and Infrared Mapping Spectrometer (VIMS), we have tentatively detected hydrogen peroxide on the surface of Enceladus, by identification of the 3.5 mu m hydrogen peroxide band. Hydrogen peroxide is produced in the solar system by bombardment of water ice with energetic particles, such as protons, electrons, and magnetospheric ions. Its detection indicates an intense radiative environment at Enceladus and can help us understand plume and surface chemistry, as well as constrain the timescale of plume activity. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. German Aerosp Ctr, D-12489 Berlin, Germany. RP Newman, SF (reprint author), CALTECH, Jet Propuls Lab, 4800 Oak Grove Dr,Mail Stop 183-501, Pasadena, CA 91109 USA. EM sarah.f.newman@jpl.nasa.gov; bonnie.j.buratti@jpl.nasa.gov; ralf.jaumann@dlr.de; james.m.bauer@jpl.nasa.gov; thomas.w.momary@jpl.nasa.gov NR 29 TC 23 Z9 23 U1 1 U2 12 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2007 VL 670 IS 2 BP L143 EP L146 DI 10.1086/524403 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235MN UT WOS:000251238500018 ER PT J AU De Paz, AG Boissier, S Madore, BF Seibert, M Joe, YH Boselli, A Wyder, TK Thilker, D Bianchi, L Rey, SC Rich, RM Barlow, TA Conrow, T Forster, K Friedman, PG Martin, DC Morrissey, P Neff, SG Schiminovich, D Small, T Donas, J Heckman, TM Lee, YW Milliard, B Szalay, AS Yi, S AF De Paz, Armando Gil Boissier, Samuel Madore, Barry F. Seibert, Mark Joe, Young H. Boselli, Alessandro Wyder, Ted K. Thilker, David Bianchi, Luciana Rey, Soo-Chang Rich, R. Michael Barlow, Tom A. Conrow, Tim Forster, Karl Friedman, Peter G. Martin, D. Christopher Morrissey, Patrick Neff, Susan G. Schiminovich, David Small, Todd Donas, Jose Heckman, Timothy M. Lee, Young-Wook Milliard, Bruno Szalay, Alex S. Yi, Sukyoung TI The GALEX ultraviolet atlas of nearby galaxies SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review DE atlases; galaxies : evolution; galaxies : fundamental parameters; galaxies : photometry; ultraviolet : galaxies ID HUBBLE-SPACE-TELESCOPE; COMPACT DWARF GALAXIES; STAR-FORMATION HISTORY; EXTRAGALACTIC DISTANCE SCALE; CAMPANAS IMAGING ATLAS; SMALL-MAGELLANIC-CLOUD; CANES VENATICI CLOUD; R-SURFACE PHOTOMETRY; GIANT BRANCH STARS; EVOLUTION-EXPLORER AB We present images, integrated photometry, and surface-brightness and color profiles for a total of 1034 nearby galaxies recently observed by the Galaxy Evolution Explorer (GALEX) satellite in its far-ultraviolet (FUV; lambda(eff) = 1516 8) and near-ultraviolet (NUV; lambda(eff) = 2267 8) bands. Our catalog of objects is derived primarily from the GALEX Nearby Galaxies Survey (NGS) supplemented by galaxies larger than 10 in diameter serendipitously found in these fields and in other GALEX exposures of similar of greater depth. The sample analyzed here adequately describes the distribution and full range of properties (luminosity, color, star formation rate [SFR]) of galaxies in the local universe. From the surface brightness profiles obtained we have computed asymptotic magnitudes, colors, and luminosities, along with the concentration indices C31 and C42. We have also morphologically classified the UV surface brightness profiles according to their shape. This data set has been complemented with archival optical, near-infrared, and far-infrared fluxes and colors. We find that the integrated (FUV - K) color provides robust discrimination between elliptical and spiral/irregular galaxies and also among spiral galaxies of different subtypes. Elliptical galaxies with brighter K-band luminosities (i.e., more massive) are redder in (NUV - K) color but bluer in (FUV - NUV) (a color sensitive to the presence of a strong UV upturn) than less massive ellipticals. In the case of the spiral/irregular galaxies our analysis shows the presence of a relatively tight correlation between the (FUV - NUV) color (or, equivalently, the slope of the UV spectrum, beta) and the total infrared-to-UV ratio. The correlation found between (FUV - NUV) color and K-band luminosity (with lower luminosity objects being bluer than more luminous ones) can be explained as due to an increase in the dust content with galaxy luminosity. The images in this Atlas along with the profiles and integrated properties are publicly available through a dedicated Web page. C1 [De Paz, Armando Gil; Boissier, Samuel; Madore, Barry F.; Joe, Young H.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Madore, Barry F.; Seibert, Mark; Wyder, Ted K.; Rey, Soo-Chang; Barlow, Tom A.; Conrow, Tim; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Schiminovich, David; Small, Todd] CALTECH, NASA IPAC Extragalact Database, Pasadena, CA 91125 USA. [Joe, Young H.; Lee, Young-Wook; Yi, Sukyoung] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Boselli, Alessandro; Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille 12, France. [Thilker, David; Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RP De Paz, AG (reprint author), Univ Complutense Madrid, Dept Astrofis, Madrid 28040, Spain. EM agpaz@ociw.edu; boissier@ociw.edu; barry@ipac.caltech.edu; mseibert@srl.caltech.edu; young@ociw.edu; alessandro.boselli@oamp.fr; wyder@srl.caltech.edu; dthilker@pha.jhu.edu; bianchi@pha.jhu.edu; screy@srl.caltech.edu; rmr@astro.ucla.edu; tab@srl.caltech.edu; tim@srl.caltech.edu; krl@srl.caltech.edu; friedman@srl.caltech.edu; cmartin@srl.caltech.edu; patrick@srl.caltech.edu; neff@stars.gsfc.nasa.gov; ds@srl.caltech.edu; tas@srl.caltech.edu; jose.donas@oamp.fr; heckman@pha.jhu.edu; ywlee@csa.yonsei.ac.kr; bruno.milliard@oamp.fr; szalay@pha.jhu.edu; yi@astro.ox.ac.uk RI Gil de Paz, Armando/J-2874-2016 OI Gil de Paz, Armando/0000-0001-6150-2854 NR 145 TC 403 Z9 403 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 185 EP 255 PG 71 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400001 ER PT J AU Treyer, M Schiminovich, D Johnson, B Seibert, M Wyder, T Barlow, TA Conrow, T Forster, K Friedman, PG Martin, DC Morrissey, P Neff, SG Small, T Bianchi, L Donas, J Heckman, TM Lee, YW Madore, BF Milliard, B Rich, RM Szalay, AS Welsh, BY Yi, SK AF Treyer, Marie Schiminovich, David Johnson, Ben Seibert, Mark Wyder, Ted Barlow, Tom A. Conrow, Tim Forster, Karl Friedman, Peter G. Martin, D. Christopher Morrissey, Patrick Neff, Susan G. Small, Todd Bianchi, Luciana Donas, Jose Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Milliard, Bruno Rich, R. Michael Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung K. TI Extinction-corrected star formation rates empirically derived from ultraviolet-optical colors SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : evolution; galaxies : fundamental parameters; surveys; ultraviolet : galaxies ID DIGITAL SKY SURVEY; GALAXY LUMINOSITY FUNCTION; MASS-METALLICITY RELATION; FORMING GALAXIES; DUST ATTENUATION; FORMATION HISTORIES; STARBURST GALAXIES; EVOLUTION-EXPLORER; REDSHIFT GALAXIES; STELLAR CONTINUA AB Using a sample of galaxies from the Sloan Digital Sky Survey spectroscopic catalog with measured star formation rates (SFRs) and ultraviolet (UV) photometry from the GALEX Medium Imaging Survey, we derived empirical linear correlations between the SFR to UV luminosity ratio and the UV-optical colors of blue-sequence galaxies. The relations provide a simple prescription to correct UV data for dust attenuation that best reconciles the SFRs derived from UV and emission-line data. The method breaks down for the red-sequence population as well as for very blue galaxies such as the local "supercompact" UV luminous galaxies and the majority of high-redshift Lyman break galaxies, which form a low-attenuation sequence of their own. C1 [Treyer, Marie; Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille 12, France. [Treyer, Marie; Wyder, Ted; Barlow, Tom A.; Conrow, Tim; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Small, Todd] CALTECH, Pasadena, CA 91125 USA. [Schiminovich, David; Johnson, Ben] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Seibert, Mark; Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Neff, Susan G.; Szalay, Alex S.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Heckman, Timothy M.; Yi, Sukyoung K.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Young-Wook] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Treyer, M (reprint author), Lab Astrophys Marseille, BP 8,Traverse Siphon, F-13376 Marseille 12, France. EM treyer@srl.caltech.edu NR 52 TC 39 Z9 40 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 256 EP 266 DI 10.1086/521794 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400002 ER PT J AU Salim, S Rich, RM Charlot, S Brinchmann, J Johnson, BD Schiminovich, D Seibert, M Mallery, R Heckman, TM Forster, K Friedman, PG Martin, DC Morrissey, P Neff, SG Small, T Wyder, TK Bianchi, L Donas, J Lee, YW Madore, BF Milliard, B Szalay, AS Welsh, BY Yi, SK AF Salim, Samir Rich, R. Michael Charlot, Stephane Brinchmann, Jarle Johnson, Benjamin D. Schiminovich, David Seibert, Mark Mallery, Ryan Heckman, Timothy M. Forster, Karl Friedman, Peter G. Martin, D. Christopher Morrissey, Patrick Neff, Susan G. Small, Todd Wyder, Ted K. Bianchi, Luciana Donas, Jose Lee, Young-Wook Madore, Barry F. Milliard, Bruno Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung K. TI UV star formation rates in the local universe SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : active; galaxies : evolution; galaxies : fundamental parameters; surveys; ultraviolet : galaxies ID GALAXY-EVOLUTION-EXPLORER; INITIAL MASS FUNCTION; DIGITAL SKY SURVEY; ULTRAVIOLET LUMINOSITY DENSITY; ACTIVE GALACTIC NUCLEI; FORMATION HISTORY; FORMING GALAXIES; DISK GALAXIES; STARBURST GALAXIES; DUST ATTENUATION AB We measure star formation rates (SFRs) of approximate to 50,000 optically selected galaxies in the local universe (z approximate to 0: 1) from gas-rich dwarfs to massive ellipticals. We obtain dust-corrected SFRs by fitting the GALEX (ultraviolet) and SDSS photometry to a library of dust-attenuated population synthesis models. For star-forming galaxies, our UV-based SFRs compare remarkably well with those from SDSS-measured emission lines (H alpha). Deviations from perfect agreement are shown to be due to differences in the dust attenuation estimates. In contrast to H alpha measurements, UV provides reliable SFRs for galaxies with weak H alpha, and where H alpha is contaminated with AGN emission (1/2 of the sample). Using full-SED SFRs, we calibrate a simple prescription that uses GALEX far- and near-UV magnitudes to produce dust-corrected SFRs for normal star-forming galaxies. The specific SFR is considered as a function of stellar mass for (1) star-forming galaxies with no AGNs, (2) those hosting an AGN, and (3) galaxies without H alpha emission. We find that the three have distinct star formation histories, with AGNs lying intermediate between the star-forming and the quiescent galaxies. Star-forming galaxies without an AGN lie on a relatively narrow linear sequence. Remarkably, galaxies hosting a strong AGN appear to represent the massive continuation of this sequence. On the other hand, weak AGNs, while also massive, have lower SFRs, sometimes extending to the realm of quiescent galaxies. We propose an evolutionary sequence for massive galaxies that smoothly connects normal star-forming galaxies to quiescent galaxies via strong and weak AGNs. We confirm that some galaxies with no H alpha show signs of star formation in the UV. We derive a cosmic star formation density at z 0: 1 with significantly smaller total error than previous measurements. C1 [Salim, Samir; Rich, R. Michael; Mallery, Ryan] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Charlot, Stephane] CNRS, Inst Astrophys Paris, F-75014 Paris, France. [Brinchmann, Jarle] Univ Porto, Ctr Astrofis, P-4150762 Oporto, Portugal. [Johnson, Benjamin D.; Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Seibert, Mark] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Small, Todd; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille 12, France. [Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Salim, S (reprint author), Natl Opt Astron Observ, 950 N Cherry Ave, Tucson, AZ 85719 USA. EM samir@noao.edu RI Brinchmann, Jarle/M-2616-2015; OI Brinchmann, Jarle/0000-0003-4359-8797; Salim, Samir/0000-0003-2342-7501 NR 84 TC 746 Z9 748 U1 0 U2 29 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 267 EP 292 DI 10.1086/519218 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400003 ER PT J AU Wyder, TK Martin, DC Schiminovich, D Seibert, M Budavari, T Treyer, MA Barlow, TA Forster, K Friedman, PG Morrissey, P Neff, SG Small, T Bianchi, L Donas, J Heckman, TM Lee, YW Madore, BF Milliard, B Rich, RM Szalay, AS Welsh, BY Yi, SK AF Wyder, Ted K. Martin, D. Christopher Schiminovich, David Seibert, Mark Budavari, Tamas Treyer, Marie A. Barlow, Tom A. Forster, Karl Friedman, Peter G. Morrissey, Patrick Neff, Susan G. Small, Todd Bianchi, Luciana Donas, Jose Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Milliard, Bruno Rich, R. Michael Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung K. TI The UV-optical galaxy color-magnitude diagram. I. Basic properties SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : evolution; galaxies : fundamental parameters; galaxies : luminosity function, mass function; galaxies : statistics; ultraviolet : galaxies ID DIGITAL-SKY-SURVEY; STAR-FORMING GALAXIES; LUMINOSITY FUNCTION; EVOLUTION-EXPLORER; REDSHIFT SURVEY; STARBURST GALAXIES; ULTRAVIOLET COLOR; FORMATION HISTORY; DUST ATTENUATION; STELLAR MASS AB We have analyzed the bivariate distribution of galaxies as a function of ultraviolet-optical colors and absolute magnitudes in the local universe. The sample consists of galaxies with redshifts and optical photometry from the Sloan Digital Sky Survey (SDSS) main galaxy sample matched with detections in the near-ultraviolet (NUV) and far-ultraviolet (FUV) bands in the Medium Imaging Survey being carried out by the Galaxy Evolution Explorer (GALEX) satellite. In the (NUV-r)(0.1) versus M-r,M-0.1 galaxy color-magnitude diagram, the galaxies separate into two well-defined blue and red sequences. The (NUV-r)(0.1) color distribution at each M-r,M-0.1 is not well fit by the sum of two Gaussians due to an excess of galaxies in between the two sequences. The peaks of both sequences become redder with increasing luminosity, with a distinct blue peak visible up to M-r,M-0.1 similar to -23. The r(0.1)-band luminosity functions vary systematically with color, with the faint-end slope and characteristic luminosity gradually increasing with color. After correcting for attenuation due to dust, we find that approximately one-quarter of the color variation along the blue sequence is due to dust, with the remainder due to star formation history and metallicity. Finally, we present the distribution of galaxies as a function of specific star formation rate and stellar mass. The specific star formation rates imply that galaxies along the blue sequence progress from low-mass galaxies with star formation rates that increase somewhat with time to more massive galaxies with a more or less constant star formation rate. Above a stellar mass of similar to 10(10.5) M-circle dot, galaxies with low ratios of current to past averaged star formation rate begin to dominate. C1 [Wyder, Ted K.; Martin, D. Christopher; Treyer, Marie A.; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Morrissey, Patrick; Small, Todd] CALTECH, Pasadena, CA 91125 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Budavari, Tamas; Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Treyer, Marie A.; Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille, France. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophy, Seoul 120749, South Korea. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Wyder, TK (reprint author), CALTECH, MC 405-47,1200 E Calif Blvd, Pasadena, CA 91125 USA. EM wyder@srl.caltech.edu NR 60 TC 206 Z9 206 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 293 EP 314 DI 10.1086/521402 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400004 ER PT J AU Schiminovich, D Wyder, TK Martin, DC Johnson, BD Salim, S Seibert, M Treyer, MA Budavari, T Hoopes, C Zamojski, M Barlow, TA Forster, KG Friedman, PG Morrissey, P Neff, SG Small, TA Bianchi, L Donas, J Heckman, TM Lee, YW Madore, BF Milliard, B Rich, RM Szalay, AS Welsh, BY Yi, S AF Schiminovich, David Wyder, Ted K. Martin, D. Christopher Johnson, Benjamin. D. Salim, Samir Seibert, Mark Treyer, Marie A. Budavari, Tamas Hoopes, Charles Zamojski, Michel Barlow, Tom A. Forster, Karl G. Friedman, Peter G. Morrissey, Patrick Neff, Susan G. Small, Todd A. Bianchi, Luciana Donas, Jose Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Milliard, Bruno Rich, R. Michael Szalay, Alex. S. Welsh, Barry Y. Yi, Sukyoung TI The UV-optical color magnitude diagram. II. Physical properties and morphological evolution on and off of a star-forming sequence SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : evolution; galaxies : formation; surveys; ultraviolet : galaxies ID DIGITAL SKY SURVEY; GALAXY LUMINOSITY FUNCTION; COSMOLOGICAL SPH SIMULATIONS; ACTIVE GALACTIC NUCLEI; AEGIS FIELD GALAXIES; ELLIPTIC GALAXIES; FORMATION HISTORY; FORMATION RATES; STELLAR MASS; DUST ATTENUATION AB We use the UV-optical color magnitude diagram in combination with spectroscopic and photometric measurements derived from the SDSS spectroscopic sample to measure the distribution of galaxies in the local universe (z < 0.25) and their physical properties as a function of specific star formation rate (SFR/M-star) and stellar mass (M-star). Throughout this study our emphasis is on the properties of galaxies on and off of a local "star-forming sequence." We discuss how the physical characteristics of galaxies along this sequence are related to scaling relations typically derived for galaxies of different morphological types. We find, among other trends, that our measure of the star formation rate surface density, Sigma(SFR), is nearly constant along this sequence. We discuss this result and implications for galaxies at higher redshift. For the first time, we report on measurements of the local UV luminosity function versus galaxy structural parameters, as well as inclination. We also split our sample into disk-dominated and bulge-dominated subsamples using the i-band Sersic index and find that disk-dominated galaxies occupy a very tight locus in SFR/M-star vs. M-star space, while bulge-dominated galaxies display a much larger spread of SFR/M-star at fixed stellar mass. A significant fraction of galaxies with SFR/M-star and Sigma(SFR) above those on the "star-forming sequence" are bulge-dominated. We can use our derived distribution functions to ask whether a significant fraction of these galaxies may be experiencing a final episode of star formation (possibly induced by a merger or other burst), soon to be quenched, by determining whether this population can explain the growth rate of the non-star-forming galaxies on the "red sequence." We find that this is a plausible scenario for bulge-dominated galaxies near the characteristic transition mass under reasonable assumptions regarding quenching timescales. Similarly, we use this technique to estimate the rate of mergers/starbursts that take galaxies off of the star-forming sequence and show that the implied merger rates are consistent with local measurements. C1 [Schiminovich, David; Johnson, Benjamin. D.; Zamojski, Michel] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Wyder, Ted K.; Martin, D. Christopher; Treyer, Marie A.; Barlow, Tom A.; Forster, Karl G.; Friedman, Peter G.; Morrissey, Patrick; Small, Todd A.] CALTECH, Pasadena, CA 91125 USA. [Salim, Samir] Natl Opt Astron Observ, Tucson, AZ 85719 USA. [Salim, Samir; Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Seibert, Mark; Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Treyer, Marie A.; Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille, France. [Budavari, Tamas; Hoopes, Charles; Heckman, Timothy M.; Szalay, Alex. S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Schiminovich, D (reprint author), Columbia Univ, Dept Astron, 550 West 120th St, New York, NY 10027 USA. EM ds@astro.columbia.edu OI Salim, Samir/0000-0003-2342-7501 NR 90 TC 177 Z9 177 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 315 EP 341 DI 10.1086/524659 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400005 ER PT J AU Martin, DC Wyder, TK Schiminovich, D Barlow, TA Forster, K Friedman, PG Morrissey, P Neff, SG Seibert, M Small, T Welsh, BY Bianchi, L Donas, J Heckman, TM Lee, YW Madore, BF Milliard, B Rich, RM Szalay, AS Yi, SK AF Martin, D. Christopher Wyder, Ted K. Schiminovich, David Barlow, Tom A. Forster, Karl Friedman, Peter G. Morrissey, Patrick Neff, Susan G. Seibert, Mark Small, Todd Welsh, Barry Y. Bianchi, Luciana Donas, Jose Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Milliard, Bruno Rich, R. Michael Szalay, Alex S. Yi, Sukyoung K. TI The UV-optical galaxy color-magnitude diagram. III. Constraints on evolution from the blue to the red sequence SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : evolution; ultraviolet : galaxies ID DIGITAL SKY SURVEY; STAR-FORMATION; BLACK-HOLES; LUMINOSITY; ULTRAVIOLET; COMBO-17; MERGERS; GROWTH; DEEP2; MASS AB We introduce a new quantity, the mass flux density of galaxies evolving from the blue sequence to the red sequence. We propose a simple technique for constraining this mass flux using the volume-corrected number density in the extinction-corrected UV-optical color-magnitude distribution, the stellar age indexes H delta(A) and D-n(4000), and a simple prescription for spectral evolution using a quenched star formation history. We exploit the excellent separation of red and blue sequences in the NUV-r band Hess function. The final value we measure, <(rho)over dot>(T) = 0.033 M-circle dot yr(-1) Mpc(-3), is strictly speaking an upper limit due to the possible contributions of bursting, composite, and extincted galaxies. However, it compares favorably with estimates of the average mass flux that we make based on the red luminosity function evolution derived from the DEEP2 and COMBO-17 surveys,<(rho)over dot>(R) = +0.034 M-circle dot yr(-1) Mpc(-3). We find that the blue sequence mass has remained roughly constant since z 1 (<(rho)over dot>B similar or equal to 0.01M(circle dot) yr(-1) Mpc(-3), but the average on- going star formation of <(rho)over dot>(SF) similar or equal to 0.037M(circle dot) yr(-1) Mpc(-3) over 0 < z < 1 is balanced by mass flux off the blue sequence. We explore the nature of the galaxies in the transition zone with particular attention to the frequency and impact of active galactic nuclei (AGNs). The AGN fraction peaks in the transition zone. We find circumstantial, albeit weak evidence that the quench rates are higher in higher luminosity AGNs. C1 [Martin, D. Christopher; Wyder, Ted K.; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Morrissey, Patrick; Seibert, Mark; Small, Todd] CALTECH, Pasadena, CA 91125 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Donas, Jose] Lab Astrophys Marseille, F-13376 Marseille, France. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophy, Seoul 120749, South Korea. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Martin, DC (reprint author), CALTECH, MC 405-47,1200 E Calif Blvd, Pasadena, CA 91125 USA. NR 23 TC 131 Z9 131 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 342 EP 356 DI 10.1086/516639 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400006 ER PT J AU Kauffmann, G Heckman, TM Budavari, T Charlot, S Hoopes, CG Martin, DC Seibert, M Barlow, TA Bianchi, L Conrow, T Donas, J Forster, K Friedman, PG Lee, YW Madore, BF Milliard, B Morrissey, PF Neff, SG Rich, RM Schiminovich, D Small, T Szalay, AS Wyder, TK Yi, SK AF Kauffmann, Guinevere Heckman, Timothy M. Budavari, Tamas Charlot, Stephane Hoopes, Charles G. Martin, D. Christopher Seibert, Mark Barlow, Tom A. Bianchi, Luciana Conrow, Tim Donas, Jose Forster, Karl Friedman, Peter G. Lee, Young-Wook Madore, Barry F. Milliard, Bruno Morrissey, Patrick F. Neff, Susan G. Rich, R. Michael Schiminovich, David Small, Todd Szalay, Alex S. Wyder, Ted K. Yi, Sukyoung K. TI Ongoing formation of bulges and black holes in the local universe: New insights from GALEX SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : active; galaxies : bulges; galaxies : elliptical and lenticular, cD; galaxies : formation ID DIGITAL SKY SURVEY; EARLY-TYPE GALAXIES; ACTIVE GALACTIC NUCLEI; COLOR-MAGNITUDE RELATION; CENTRAL CLUSTER GALAXIES; STAR-FORMING GALAXIES; EVOLUTION-EXPLORER; COOLING FLOWS; HOST GALAXIES; STELLAR MASS AB We analyze a volume-limited sample of massive bulge-dominated galaxies with data from both the Sloan Digital Sky Survey and the Galaxy Evolution Explorer (GALEX) satellite. The galaxies have central velocity dispersions greater than 100 km s(-1) and stellar surface mass densities that lie above the value where galaxies transition from actively star-forming to passive systems. The sample is limited to redshifts 0.03 < z < 0.07. At these distances, the SDSS spectra sample the light from the bulge-dominated central regions of the galaxies. The GALEX NUV data provide high sensitivity to low rates of global star formation in these systems. Our sample of bulge-dominated galaxies exhibits a much larger dispersion in NUV-r color than in optical g-r color. The dispersion increases for galaxies with smaller central velocity dispersions, and nearly all of the galaxies with bluer NUV-r colors are active galactic nuclei (AGNs). Both GALEX images and SDSS color profiles demonstrate that the excess UV light is nearly always associated with an extended disk. When comparing fiber-based estimates of stellar age to global ones, we find that galaxies with red outer regions almost never have a young bulge or a strong AGN. Galaxies with blue outer regions have bulges and black holes that span a wide range in age and accretion rate. Galaxies with young bulges and strongly accreting black holes almost always have blue outer disks. The black hole growth rate correlates much more strongly with the age of the stars in the bulge than in the disk. Our suggested scenario is one in which the source of gas that builds the bulge and black hole is a low-mass reservoir of cold gas in the disk. The presence of this gas is a necessary but not sufficient condition for bulge and black hole growth. Some mechanism must transport this gas inward in a time variable way. The disk gas itself is likely to be the result of the accretion of gas from an external source. As the gas in the disk is converted into stars, galaxies will turn red, but further inflow can bring them back into the blue NUV-r sequence. C1 [Kauffmann, Guinevere] Max Planck Inst Astrophys, D-85748 Garching, Germany. [Heckman, Timothy M.; Budavari, Tamas; Hoopes, Charles G.; Bianchi, Luciana; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Charlot, Stephane] Inst Astrophys Paris, UMR 7095, F-75014 Paris, France. [Martin, D. Christopher; Seibert, Mark; Barlow, Tom A.; Conrow, Tim; Forster, Karl; Friedman, Peter G.; Morrissey, Patrick F.; Small, Todd; Wyder, Ted K.] CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. [Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille, France. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Madore, Barry F.] CALTECH, NASA IPAC Extragalact Database, Pasadena, CA 91125 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. RP Kauffmann, G (reprint author), Max Planck Inst Astrophys, Karl Schwarzschild Str 1, D-85748 Garching, Germany. NR 46 TC 76 Z9 76 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 357 EP 376 DI 10.1086/516647 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400007 ER PT J AU Johnson, BD Schiminovich, D Seibert, M Treyer, M Martin, DC Barlow, TA Forster, K Friedman, PG Morrissey, P Neff, SG Small, T Wyder, TK Bianchi, L Donas, J Heckman, TM Lee, YW Madore, BF Milliard, B Rich, RM Szalay, AS Welsh, BY Yi, SK AF Johnson, Benjamin D. Schiminovich, David Seibert, Mark Treyer, Marie Martin, D. Christopher Barlow, Tom A. Forster, Karl Friedman, Peter G. Morrissey, Patrick Neff, Susan G. Small, Todd Wyder, Ted K. Bianchi, Luciana Donas, Jose Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Milliard, Bruno Rich, R. Michael Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung K. TI Ultraviolet, optical, and infrared constraints on models of stellar populations and dust attenuation SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE dust, extinction; galaxies : evolution; galaxies : fundamental parameters; infrared : galaxies; ultraviolet : galaxies ID STAR-FORMING GALAXIES; DIGITAL SKY SURVEY; SPECTRAL ENERGY-DISTRIBUTIONS; COLOR-MAGNITUDE DISTRIBUTION; INITIAL MASS FUNCTION; STARBURST GALAXIES; NEARBY GALAXIES; FIELD GALAXIES; FORMATION RATES; DISK GALAXIES AB The color of galaxies is a fundamental property, easily measured, that constrains models of galaxies and their evolution. Dust attenuation and star formation history (SFH) are the dominant factors affecting the color of galaxies. Here we explore the empirical relation between SFH, attenuation, and color for a wide range of galaxies, including early types. These galaxies have been observed by GALEX, SDSS, and Spitzer, allowing the construction of measures of dust attenuation from the ratio of infrared (IR) to ultraviolet (UV) flux and measures of SFH from the strength of the 4000 angstrom break. The empirical relation between these three quantities is compared to models that separately predict the effects of dust and SFH on color. This comparison demonstrates the quantitative consistency of these simple models with the data and hints at the power of multiwavelength data for constraining these models. The UV color is a strong constraint; we find that a Milky Way extinction curve is disfavored, and that the UV emission of galaxies with large 4000 angstrom break strengths is likely to arise from evolved populations. We perform fits to the relation between SFH, attenuation, and color. This relation links the production of starlight and its absorption by dust to the subsequent reemission of the absorbed light in the IR. Galaxy models that self-consistently treat dust absorption and emission as well as stellar populations will need to reproduce these fitted relations in the low-redshift universe. C1 [Johnson, Benjamin D.; Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Seibert, Mark; Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Treyer, Marie; Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille, France. [Treyer, Marie; Martin, D. Christopher; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Morrissey, Patrick; Small, Todd; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Johnson, BD (reprint author), Columbia Univ, Dept Astron, New York, NY 10027 USA. NR 76 TC 40 Z9 41 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 377 EP 391 DI 10.1086/522932 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400008 ER PT J AU Johnson, BD Schiminovich, D Seibert, M Treyer, M Martin, DC Barlow, TA Forster, K Friedman, PG Morrissey, P Neff, SG Small, T Wyder, TK Bianchi, L Donas, J Heckman, TM Lee, YW Madore, BF Milliard, B Rich, RM Szalay, AS Welsh, BY Yi, SK AF Johnson, Benjamin D. Schiminovich, David Seibert, Mark Treyer, Marie Martin, D. Christopher Barlow, Tom A. Forster, Karl Friedman, Peter G. Morrissey, Patrick Neff, Susan G. Small, Todd Wyder, Ted K. Bianchi, Luciana Donas, Jose Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Milliard, Bruno Rich, R. Michael Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung K. TI Ultraviolet through infrared spectral energy distributions from 1000 SDSS galaxies: Dust attenuation SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE dust, extinction; galaxies : evolution; galaxies : fundamental parameters; infrared : galaxies; ultraviolet : galaxies ID STAR-FORMING GALAXIES; HIGH-REDSHIFT GALAXIES; DIGITAL SKY SURVEY; FORMATION HISTORY; FIELD GALAXIES; LUMINOSITY DENSITY; STARBURST GALAXIES; SPIRAL GALAXIES; FORMATION RATES; DISK GALAXIES AB The meaningful comparison of models of galaxy evolution to observations is critically dependent on the accurate treatment of dust attenuation. To investigate dust absorption and emission in galaxies we have assembled a sample of similar to 1000 galaxies with UV through IR photometry from GALEX, SDSS, and Spitzer, and optical spectroscopy from SDSS. The ratio of IR to UV emission (IRX) is used to constrain the dust attenuation in galaxies. We use the 4000 angstrom break as a robust and useful, although coarse, indicator of star formation history (SFH). We examine the relationship between IRX and the UV spectral slope (a common attenuation indicator at high redshift) and find little dependence of the scatter on D-n(4000). We construct average UV through far-IR spectral energy distributions (SEDs) for different ranges of IRX, D-n(4000), and stellar mass (M-*) to show the variation of the entire SED with these parameters. When binned simultaneously by IRX, D-n(4000), and M-* these SEDs allow us to determine a low-resolution average attenuation curve for different ranges of M-*. The attenuation curves thus derived are consistent with a lambda(-0.7) attenuation law, and we find no significant variations with M-*. Finally, we show the relationship between IRX and the global stellar mass surface density and gas-phase metallicity. Among star-forming galaxies we find a strong correlation between IRX and stellar mass surface density, even at constant metallicity, a result that is closely linked to the well-known correlation between IRX and star formation rate. C1 [Johnson, Benjamin D.; Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Seibert, Mark; Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Treyer, Marie; Martin, D. Christopher; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Morrissey, Patrick; Small, Todd; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Treyer, Marie; Donas, Jose; Milliard, Bruno] Lan Astrophys Marseille, F-13376 Marseille, France. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Johnson, BD (reprint author), Columbia Univ, Dept Astron, New York, NY 10027 USA. NR 59 TC 48 Z9 48 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 392 EP 403 DI 10.1086/522960 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400009 ER PT J AU Buat, V Takeuchi, TT Iglesias-Paramo, J Xu, CK Burgarella, D Boselli, A Barlow, T Bianchi, L Donas, J Forster, K Friedman, PG Heckman, TM Lee, YW Madore, BF Martin, DC Milliard, B Morissey, P Neff, S Rich, M Schiminovich, D Seibert, M Small, T Szalay, AS Welsh, B Wyder, T Yi, SK AF Buat, V. Takeuchi, T. T. Iglesias-Paramo, J. Xu, C. K. Burgarella, D. Boselli, A. Barlow, T. Bianchi, L. Donas, J. Forster, K. Friedman, P. G. Heckman, T. M. Lee, Y. -W. Madore, B. F. Martin, D. C. Milliard, B. Morissey, P. Neff, S. Rich, M. Schiminovich, D. Seibert, M. Small, T. Szalay, A. S. Welsh, B. Wyder, T. Yi, S. K. TI The local universe as seen in the far-infrared and far-ultraviolet: A global point of view of the local recent star formation SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE dust, extinction; galaxies : photometry; galaxies : stellar content; infrared : galaxies; ultraviolet : galaxies ID GALAXY LUMINOSITY FUNCTION; LYMAN-BREAK GALAXIES; DIGITAL SKY SURVEY; FORMING GALAXIES; FORMATION RATES; DEEP-FIELD; FORMATION HISTORY; DUST ATTENUATION; NEARBY UNIVERSE; DISK GALAXIES AB We select far-infrared (FIR: 60 mu m) and far-ultraviolet (FUV: 530 angstrom) samples of nearby galaxies in order to discuss the biases encountered by monochromatic surveys (FIR or FUV). Very different volumes are sampled by each selection, and much care is taken to apply volume corrections to all the analyses. The distributions of the bolometric luminosity of young stars are compared for both samples: they are found to be consistent with each other for galaxies of intermediate luminosities, but some differences are found for high (>5 x 10(10) L-circle dot) luminosities. The shallowness of the IRAS survey prevents us from securing a comparison at low luminosities (<2 x 10(9) L-circle dot). The ratio of the total infrared (TIR) luminosity to the FUV luminosity is found to increase with the bolometric luminosity in a similar way for both samples up to 5 x 10(10) L-circle dot. Brighter galaxies are found to have a different behavior according to their selection: the L-TIR/L-FUV ratio of the FUV-selected galaxies brighter than 5 x 10(10) L-circle dot reaches a plateau, whereas L-TIR/L-FUV continues to increase with the luminosity of bright galaxies selected in FIR. The volume-averaged specific star formation rate (SFR per unit galaxy stellar mass, SSFR) is found to decrease toward massive galaxies within each selection. The mean values of the SSFR are found to be larger than those measured for optical and NIR-selected samples over the whole mass range for the FIR selection, and for masses larger than 10(10) M-circle dot for the FUV selection. Luminous and massive galaxies selected in FIR appear as active as galaxies with similar characteristics detected at z similar to 0.7. C1 [Buat, V.; Takeuchi, T. T.; Burgarella, D.; Boselli, A.; Donas, J.; Milliard, B.] Lab Astrophys Marseille, F-13012 Marseille, France. [Takeuchi, T. T.; Barlow, T.] Tohoku Univ, Inst Astron, Aoba Ku, Sendai, Miyagi 9808578, Japan. [Iglesias-Paramo, J.] Inst Astrofis Andalucia, CSIC, Granada 18008, Spain. [Xu, C. K.; Forster, K.; Friedman, P. G.; Martin, D. C.; Morissey, P.; Seibert, M.; Small, T.; Wyder, T.] CALTECH, Pasadena, CA 91125 USA. [Bianchi, L.] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Heckman, T. M.; Szalay, A. S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Y. -W.; Yi, S. K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Madore, B. F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Madore, B. F.] CALTECH, NASA IPAC Extragalact Database, Pasadena, CA 91125 USA. [Neff, S.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Rich, M.] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Schiminovich, D.] Columbia Univ Barnard Coll, Dept Astron, New York, NY 10027 USA. [Welsh, B.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Buat, V (reprint author), Lab Astrophys Marseille, F-13012 Marseille, France. OI Iglesias-Paramo, Jorge/0000-0003-2726-6370 NR 67 TC 65 Z9 65 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 404 EP 414 DI 10.1086/516645 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400010 ER PT J AU Martin, DC Small, T Schiminovich, D Wyder, TK Perez-Gonzalez, PG Johnson, B Wolf, C Barlow, TA Forster, K Friedman, PG Morrissey, P Neff, SG Seibert, M Welsh, BY Bianchi, L Donas, J Heckman, TM Lee, YW Madore, BF Milliard, B Rich, RM Szalay, AS Yi, SK Meisenheimer, K Rieke, G AF Martin, D. Christopher Small, Todd Schiminovich, David Wyder, Ted K. Perez-Gonzalez, Pablo G. Johnson, Benjamin Wolf, Christian Barlow, Tom A. Forster, Karl Friedman, Peter G. Morrissey, Patrick Neff, Susan G. Seibert, Mark Welsh, Barry Y. Bianchi, Luciana Donas, Jose Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Milliard, Bruno Rich, R. Michael Szalay, Alex S. Yi, Sukyoung K. Meisenheimer, Klaus Rieke, George TI The star formation and extinction coevolution of UV-selected galaxies over 0.05 < z < 1.2 SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : evolution; ultraviolet : galaxies ID ULTRAVIOLET LUMINOSITY DENSITY; MASS-METALLICITY RELATION; FORMING GALAXIES; STELLAR MASS; EVOLUTION-EXPLORER; COMBO-17 SURVEY; FIELD GALAXIES; HIGH-REDSHIFT; DEEP FIELDS; SPITZER AB We use a new stacking technique to obtain mean mid-IR and far-IR to far-UV flux ratios over the rest-frame near-UV, near-IR color-magnitude diagram. We employ COMBO-17 redshifts and COMBO-17 optical, GALEX far- and near-UV, and Spitzer IRAC and MIPS mid-IR photometry. This technique permits us to probe the infrared excess (IRX), the ratio of far-IR to far-UV luminosity, and the specific star formation rate (SSFR) and their coevolution over 2 orders of magnitude of stellar mass and over redshift 0.1 < z < 1.2. We find that the SSFR and the characteristic mass (M-0) above which the SSFR drops increase with redshift (downsizing). At any given epoch, the IRX is an increasing function of mass up to M-0. Above this mass the IRX falls, suggesting gas exhaustion. In a given mass bin below M-0, the IRX increases with time in a fashion consistent with enrichment. We interpret these trends using a simple model with a Schmidt-Kennicutt law and extinction that tracks gas density and enrichment. We find that the average IRX and SSFR follow a galaxy age parameter xi, which is determined mainly by the galaxy mass and time since formation. We conclude that blue-sequence galaxies have properties which show simple, systematic trends with mass and time such as the steady buildup of heavy elements in the interstellar media of evolving galaxies and the exhaustion of gas in galaxies that are evolving off the blue sequence. The IRX represents a tool for selecting galaxies at various stages of evolution. C1 [Martin, D. Christopher; Small, Todd; Wyder, Ted K.; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Morrissey, Patrick; Seibert, Mark] CALTECH, Pasadena, CA 91125 USA. [Schiminovich, David; Johnson, Benjamin] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Perez-Gonzalez, Pablo G.; Rieke, George] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. [Wolf, Christian] Univ Oxford, Dept Phys, Oxford OX1 3RHU, England. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille, France. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Meisenheimer, Klaus] Max Planck Inst Astron, D-69117 Heidelberg, Germany. RP Martin, DC (reprint author), CALTECH, MC 405-47,1200 E Calif Blvd, Pasadena, CA 91125 USA. RI Perez-Gonzalez, Pablo/J-2871-2016 OI Perez-Gonzalez, Pablo/0000-0003-4528-5639 NR 45 TC 46 Z9 46 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 415 EP 431 DI 10.1086/522088 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400011 ER PT J AU Xu, CK Shupe, D Buat, V Rowan-Robinson, M Babbedge, T Iglesias-Paramo, J Takeuchi, TT Barlow, TA Conrow, T Fang, F Forster, K Friedman, PG Gonzales-Solares, E Lonsdale, C Martin, DC Morrissey, P Neff, SG Schiminovich, D Seibert, M Small, T Smith, G Surace, J Wyder, TK AF Xu, C. Kevin Shupe, David Buat, Veronique Rowan-Robinson, Michael Babbedge, Thomas Iglesias-Paramo, Jorge Takeuchi, Tsutomu T. Barlow, Tom A. Conrow, Tim Fang, Fan Forster, Karl Friedman, Peter G. Gonzales-Solares, Eduardo Lonsdale, Carol Martin, D. Christopher Morrissey, Patrick Neff, Susan G. Schiminovich, David Seibert, Mark Small, Todd Smith, Gene Surace, Jason Wyder, Ted K. TI IR and UV galaxies at z=0.6: Evolution of dust attenuation and stellar mass as revealed by SWIRE and GALEX SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE dust, extinction; galaxies : active; galaxies : evolution; infrared : galaxies; ultraviolet : galaxies ID STAR-FORMATION RATE; SPITZER-SPACE-TELESCOPE; ULTRALUMINOUS INFRARED GALAXIES; ULTRAVIOLET LUMINOSITY DENSITY; SPECTRAL ENERGY-DISTRIBUTIONS; EXTRAGALACTIC LEGACY SURVEY; DIGITAL SKY SURVEY; FORMATION HISTORY; NEARBY UNIVERSE; PHOTOMETRIC REDSHIFTS AB We study dust attenuation and stellar mass of z similar to 0.6 star-forming galaxies using new SWIRE observations in IR and GALEX observations in UV. Two samples are selected from the SWIRE and GALEX source catalogs in the SWIRE/GALEX field ELAIS-N1-00 (Omega = 0.8 deg(2)). The UV-selected sample has 600 galaxies with photometric redshift (hereafter photo-z) 0.5 <= z <= 0.7 and NUV <= 23.5 (corresponding to L-FUV >= 10(9.6) L-circle dot). The IR-selected sample contains 430 galaxies with f(24) (mu m) >= 0.2 mJy (L-dust >= 10(10.8) L-circle dot) in the same photo-z range. It is found that the mean L-dust/L-FUV ratios of the z = 0.6 UV galaxies are consistent with that of their z = 0 counterparts of the same L-FUV. For IR galaxies, the mean L-dust/L-FUV ratios of the z = 0.6 LIRGs (L-dust similar to 10(11) L-circle dot) are about a factor of 2 lower than local LIRGs, whereas z = 0.6 ULIRGs (L-dust similar to 10(12) L-circle dot) have the same mean L-dust/L-FUV ratios as their local counterparts. This is consistent with the hypothesis that the dominant component of LIRGpopulation has changed from large, gas-rich spirals at z > 0.5 to major mergers at z = 0. The stellar mass of z = 0.6 UV galaxies of L-FUV <= 10(10.2) L-circle dot is about a factor of 2 less than their local counterparts of the same luminosity, indicating growth of these galaxies. The mass of z = 0.6 UV luminous galaxies (UVLGs: L-FUV > 10(10.2) L-circle dot) and IR-selected galaxies, which are nearly exclusively LIRGs and ULIRGs, is the same as their local counterparts. C1 [Xu, C. Kevin; Conrow, Tim; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Schiminovich, David; Seibert, Mark; Small, Todd; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Xu, C. Kevin; Lonsdale, Carol] CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. [Shupe, David; Fang, Fan; Surace, Jason] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. [Buat, Veronique] Observt Astron Marseille Provence, Lab Astrophys Marseille, F-13012 Marseille, France. [Rowan-Robinson, Michael; Babbedge, Thomas] Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, London SW7 2BZ, England. [Iglesias-Paramo, Jorge] CSIC, Inst Astrofis Andalucia, Granada 18008, Spain. [Takeuchi, Tsutomu T.] Tohoku Univ, Astron Inst, Aoba Ku, Sendai, Miyagi 9808578, Japan. [Gonzales-Solares, Eduardo] Inst Astron, Cambridge CB3 0HA, England. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Small, Todd] Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. RP Xu, CK (reprint author), CALTECH, MC 405-47,1200 E Calif Blvd, Pasadena, CA 91125 USA. OI Iglesias-Paramo, Jorge/0000-0003-2726-6370 NR 63 TC 9 Z9 9 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 432 EP 440 DI 10.1086/516641 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400012 ER PT J AU Hoopes, CG Heckman, TM Salim, S Seibert, M Tremonti, CA Schiminovich, D Rich, RM Martin, DC Charlot, S Kauffmann, G Forster, K Friedman, PG Morrissey, P Neff, SG Small, T Wyder, TK Bianchi, L Donas, J Lee, YW Madore, BF Milliard, B Szalay, AS Welsh, BY Yi, SK AF Hoopes, Charles G. Heckman, Timothy M. Salim, Samir Seibert, Mark Tremonti, Christy A. Schiminovich, David Rich, R. Michael Martin, D. Christopher Charlot, Stephane Kauffmann, Guinevere Forster, Karl Friedman, Peter G. Morrissey, Patrick Neff, Susan G. Small, Todd Wyder, Ted K. Bianchi, Luciana Donas, Jose Lee, Young-Wook Madore, Barry F. Milliard, Bruno Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung K. TI The diverse properties of the most ultraviolet-luminous galaxies discovered by GALEX SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : evolution; galaxies : starburst; ultraviolet : galaxies ID STAR-FORMING GALAXIES; LYMAN-BREAK GALAXIES; DIGITAL SKY SURVEY; MASS-METALLICITY RELATION; HIGH-REDSHIFT GALAXIES; FORMATION HISTORIES; EVOLUTION-EXPLORER; FAR-ULTRAVIOLET; LOCAL UNIVERSE; DEEP SURVEY AB We report on the properties of a sample of ultraviolet-luminous galaxies (UVLGs) selected by matching the Galaxy Evolution Explorer (GALEX) All-Sky Imaging and Medium Imaging Surveys with the Sloan Digital Sky Survey third data release. The overlap between these two surveys is roughly 450 deg(2). Of 25,362 galaxies ( with SDSS spectroscopy) in the range 0.0 < z < 0.3 detected by GALEX, there are 215 galaxies with L > 2 x 10(10) L-circle dot at 1530 angstrom (observed wavelength). The properties of this population are well correlated with ultraviolet surface brightness. We find that the galaxies with low UV surface brightness are primarily large spiral systems with a mixture of old and young stellar populations, while the high surface brightness galaxies consist primarily of compact starburst systems, with an approximate boundary at a surface brightness of I-1530 = 10(8) L-circle dot kpc(-2). The large galaxies appear to be the high-luminosity tail of the galaxy star formation function and owe their large luminosity to their large surface area. In terms of the behavior of surface brightness with luminosity, size with luminosity, the mass-metallicity relation, and other parameters, the compact UVLGs clearly depart from the trends established by the full sample of galaxies. The subset of compact UVLGs with the highest surface brightness (I-1530 > 10(9) L-circle dot kpc(-2); "supercompact UVLGs") have characteristics that are remarkably similar to Lyman break galaxies at higher redshift. They are much more luminous ( and thus have much higher star formation rates) than typical local ultraviolet-bright starburst galaxies and blue compact dwarf galaxies. They have metallicities that are systematically lower than normal galaxies of the same stellar mass, indicating that they are less chemically evolved. In all these respects, they are the best local analogs for Lyman break galaxies. C1 [Hoopes, Charles G.; Heckman, Timothy M.; Bianchi, Luciana; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Salim, Samir; Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Seibert, Mark; Martin, D. Christopher; Friedman, Peter G.; Morrissey, Patrick; Small, Todd; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Tremonti, Christy A.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Charlot, Stephane; Kauffmann, Guinevere] Max Planck Inst Astron, D-85748 Garching, Germany. [Charlot, Stephane] Inst Astrophys Paris, UMR 7095, F-75014 Paris, France. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille, France. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Hoopes, CG (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Home Wood Campus, Baltimore, MD 21218 USA. OI Salim, Samir/0000-0003-2342-7501 NR 43 TC 83 Z9 83 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 441 EP 456 DI 10.1086/516644 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400013 ER PT J AU Basu-Zych, AR Schiminovich, D Johnson, BD Hoopes, C Overzier, R Treyer, MA Heckman, TM Barlow, TA Bianchi, L Conrow, T Donas, J Forster, KG Friedman, PG Lee, YW Madore, BF Martin, DC Milliard, B Morrissey, P Neff, SG Rich, RM Salim, S Seibert, M Small, TA Szalay, AS Wyder, TK Yi, S AF Basu-Zych, Antara R. Schiminovich, David Johnson, Benjamin D. Hoopes, Charles Overzier, Roderik Treyer, Marie A. Heckman, Timothy M. Barlow, Tom A. Bianchi, Luciana Conrow, Tim Donas, Jose Forster, Karl G. Friedman, Peter G. Lee, Young-Wook Madore, Barry F. Martin, D. Christopher Milliard, Bruno Morrissey, Patrick Neff, Susan G. Rich, R. Michael Salim, Samir Seibert, Mark Small, Todd A. Szalay, Alex S. Wyder, Ted K. Yi, Sukyoung TI The young and the dustless: Interpreting radio observations of ultraviolet-luminous galaxies SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : starburst; radio continuum : galaxies; ultraviolet : galaxies ID STAR-FORMING GALAXIES; COMPACT BLUE GALAXIES; DIGITAL SKY SURVEY; LYMAN-BREAK GALAXIES; NEARBY COUNTERPARTS; INFRARED PROPERTIES; STELLAR POPULATION; DWARF GALAXIES; HIGH-REDSHIFT; EVOLUTION AB Ultraviolet-luminous galaxies (UVLGs) have been identified as intensely star-forming nearby galaxies. A subset of these, the supercompact UVLGs, are believed to be local analogs of high-redshift Lyman break galaxies. Here we investigate the radio continuum properties of this important population for the first time. We have observed 42 supercompact UVLGs with the VLA, all of which have extensive coverage in the UV/optical by GALEX and SDSS. Our analysis includes comparison samples of multiwavelength data from the Spitzer First Look Survey and from the SDSS-GALEX matched catalogs. In addition we have Spitzer MIPS data for 24 of our galaxies and find that they fall on the radio-FIR correlation of normal star-forming galaxies. We find that our galaxies have lower radio to UV ratios and lower Balmer decrements than other local galaxies with similar (high) star formation rates. Optical spectra show they have lower D(n)(4000) and H delta(A) indices, higher H beta emission-line equivalent widths, and higher [O III] 5007/H beta emission-line ratios than normal star-forming galaxies. Comparing these results to galaxy spectral evolution models we conclude that supercompact UVLGs are distinguished from normal star-forming galaxies firstly by their high specific star formation rates. Moreover, compared to other types of galaxies with similar star formation rates, they have significantly less dust attenuation. In both regards they are similar to Lyman break galaxies. This suggests that the process that causes star formation in the supercompact UVLGs differs from other local star-forming galaxies, but may be similar to Lyman break galaxies. C1 [Basu-Zych, Antara R.; Schiminovich, David; Johnson, Benjamin D.] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Hoopes, Charles; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Overzier, Roderik; Heckman, Timothy M.; Salim, Samir] Natl Opt Astron Observ, Tucson, AZ USA. [Treyer, Marie A.; Barlow, Tom A.; Conrow, Tim; Forster, Karl G.; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Small, Todd A.; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Treyer, Marie A.; Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille, France. [Bianchi, Luciana; Yi, Sukyoung] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Lee, Young-Wook] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Madore, Barry F.; Seibert, Mark] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Basu-Zych, AR (reprint author), Columbia Univ, Dept Astron, 550 West 120th St, New York, NY 10027 USA. EM antara@astro.columbia.edu OI Salim, Samir/0000-0003-2342-7501 NR 48 TC 36 Z9 36 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 457 EP 470 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400014 ER PT J AU Mallery, RP Rich, RM Salim, S Small, T Charlot, S Seibert, M Wyder, T Barlow, TA Forster, K Friedman, PG Martin, DC Morrissey, P Neff, SG Schiminovich, D Bianchi, L Donas, J Heckman, TM Lee, YW Madore, BF Milliard, B Szalay, AS Welsh, BY Yi, S AF Mallery, Ryan P. Rich, R. Michael Salim, Samir Small, Todd Charlot, Stephane Seibert, Mark Wyder, Ted Barlow, Tom A. Forster, Karl Friedman, Peter G. Martin, D. Christopher Morrissey, Patrick Neff, Susan G. Schiminovich, David Bianchi, Luciana Donas, Jose Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Milliard, Bruno Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung TI Keck DEIMOS spectroscopy of a GALEX UV-selected sample from the medium imaging survey SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : active; galaxies : high-redshift; galaxies : starburst; ultraviolet : galaxies ID DIGITAL SKY SURVEY; GALAXY LUMINOSITY FUNCTION; STAR-FORMATION HISTORIES; HUBBLE DEEP FIELD; COMPACT GALAXIES; LOCAL UNIVERSE; LOW-REDSHIFT; DATA RELEASE; EVOLUTION; EMISSION AB We report results from a pilot program to obtain spectroscopy for objects detected in the Galaxy Evolution Explorer (GALEX) Medium Imaging Survey (MIS). Our study examines the properties of galaxies detected by GALEX fainter than the Sloan Digital Sky Survey (SDSS) spectroscopic survey. This is the first study to extend the techniques of Salim and coworkers to estimate stellar masses, star formation rates (SFRs), and the b (star formation history) parameter for star-forming galaxies out to z similar to 0.7. We obtain redshifts for 50 GALEX MIS sources reaching NUV = 23.9 (AB mag) having counterparts in the SDSS Data Release 4 (DR4). Of our sample, 43 are star-forming galaxies with z < 0.7, 3 have emission-line ratios indicative of active galactic nuclei with z < 0.7, and 4 objects with z > 1 are QSOs, 3 of which are not previously cataloged. We compare our sample to a much larger sample of similar to 50,000 matched GALEX/SDSS galaxies with SDSS spectroscopy; while our survey is shallow, the optical counterparts to our sources reach similar to 3 mag fainter in SDSS r than the SDSS spectroscopic sample. We use emission-line diagnostics for the galaxies to determine that the sample contains mostly star-forming galaxies. The galaxies in the sample populate the blue sequence in the NUV-r versus M-r color-magnitude diagram. The derived stellar masses of the galaxies range from 10(8) to 10(11) M-circle dot, and derived SFRs are between 10(-1) and 10(2) M-circle dot yr(-1). Our sample has SFRs, luminosities, and velocity dispersions that are similar to the samples of faint compact blue galaxies studied previously in the same redshift range by Koo and collaborators, Guzman and collaborators, and Phillips and collaborators. However, our sample is similar to 2 mag fainter in surface brightness than the compact blue galaxies. We find that the star formation histories for a majority of the galaxies are consistent with a recent starburst within the last 100 Myr. C1 [Mallery, Ryan P.; Rich, R. Michael; Salim, Samir; Morrissey, Patrick] Univ Calif Los Angeles, Los Angeles, CA 90095 USA. [Small, Todd; Seibert, Mark; Wyder, Ted; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher] CALTECH, Pasadena, CA 91125 USA. [Charlot, Stephane] Max Planck Inst Astrophys, D-85748 Garching, Germany. [Charlot, Stephane] CNRS, Lab Astronphys Paris, F-75014 Paris, France. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille 12, France. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Madore, Barry F.; Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. RP Mallery, RP (reprint author), Univ Calif Los Angeles, MC 405-47,1200 E Calif Blvd, Los Angeles, CA 90095 USA. OI Salim, Samir/0000-0003-2342-7501 NR 39 TC 1 Z9 1 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 471 EP 481 DI 10.1086/516638 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400015 ER PT J AU Mallery, RP Kewley, L Rich, RM Salim, S Charlot, S Tremonti, C Seibert, M Small, T Wyder, T Barlow, TA Forster, K Friedman, PG Martin, DC Morrissey, P Neff, SG Schiminovich, D Bianchi, L Donas, J Heckman, TM Lee, YW Madore, BF Milliard, B Szalay, AS Welsh, BY Yi, S AF Mallery, Ryan P. Kewley, Lisa Rich, R. Michael Salim, Samir Charlot, Stephane Tremonti, Christy Seibert, Mark Small, Todd Wyder, Ted Barlow, Tom A. Forster, Karl Friedman, Peter G. Martin, D. Christopher Morrissey, Patrick Neff, Susan G. Schiminovich, David Bianchi, Luciana Donas, Jose Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Milliard, Bruno Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung TI Nitrogen production in starburst galaxies detected by GALEX SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : abundances; galaxies : fundamental parameters; galaxies : starburst; ultraviolet : galaxies ID DIGITAL SKY SURVEY; STAR-FORMING GALAXIES; H-II REGIONS; EXTRAGALACTIC HII-REGIONS; DWARF IRREGULAR GALAXIES; EMISSION-LINE SPECTRA; CHEMICAL ABUNDANCES; ELECTRON TEMPERATURES; FORMATION HISTORIES; GALACTIC EVOLUTION AB We investigate the production of nitrogen in star-forming galaxies with ultraviolet (UV) radiation detected by the Galaxy Evolution Explorer Satellite (GALEX). We use a sample of 8745 GALEX emission-line galaxies matched to the Sloan Digital Sky Survey (SDSS) spectroscopic sample. We derive both gas-phase oxygen and nitrogen abundances for the sample and apply stellar population synthesis models to derive stellar masses and star formation histories of the galaxies. We compare oxygen abundances derived using three different diagnostics. We derive the specific star formation rates of the galaxies by modeling the seven-band GALEX+SDSS photometry. We find that galaxies that have log (SFR/M-*) greater than or similar to -10.0 typically have values of log (N/O) similar to 0.05 dex less than galaxies with log (SFR/M-*) less than or similar to -10.0 and similar oxygen abundances. C1 [Mallery, Ryan P.; Rich, R. Michael; Salim, Samir] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Kewley, Lisa] Univ Hawaii, Astron Inst, Honolulu, HI 96822 USA. [Charlot, Stephane] Max Planck Inst Astrophys, D-85748 Garching, Germany. [Charlot, Stephane] CNRS, Inst Astrophys Paris, F-75014 Paris, France. [Tremonti, Christy] Steward Observ, Tucson, AZ 85721 USA. [Seibert, Mark; Small, Todd; Wyder, Ted; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick] CALTECH, Pasadena, CA 91125 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Donas, Jose] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille 12, France. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Mallery, RP (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. OI Salim, Samir/0000-0003-2342-7501 NR 64 TC 12 Z9 12 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 482 EP 493 DI 10.1086/518833 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400016 ER PT J AU Milliard, B Heinis, S Blaizot, J Arnouts, S Schiminovich, D Budavari, T Donas, J Treyer, M Laget, M Viton, M Wyder, TK Szalay, AS Barlow, TA Forster, K Friedman, PG Martin, DC Morrissey, P Neff, SG Seibert, M Small, T Bianchi, L Heckman, TM Lee, YW Madore, BF Rich, RM Welsh, BY Yi, SK Xu, CK AF Milliard, Bruno Heinis, Sebastien Blaizot, Jeremy Arnouts, Stephane Schiminovich, David Budavari, Tamas Donas, Jose Treyer, Marie Laget, Michel Viton, Maurice Wyder, Ted K. Szalay, Alex S. Barlow, Tom A. Forster, Karl Friedman, Peter G. Martin, D. Christopher Morrissey, Patrick Neff, Susan G. Seibert, Mark Small, Todd Bianchi, Luciana Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Rich, R. Michael Welsh, Barry Y. Yi, Sukyoung K. Xu, C. K. TI Clustering properties of rest-frame UV-selected galaxies. I. The correlation length derived from GALEX data in the local universe SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE stars : formation; ultraviolet : galaxies ID LYMAN-BREAK GALAXIES; DIGITAL SKY SURVEY; STAR-FORMATION HISTORY; ULTRAVIOLET LUMINOSITY DENSITY; ANGULAR-CORRELATION FUNCTION; REDSHIFT SURVEY; SPECTRAL TYPE; EVOLUTION-EXPLORER; COLOR DEPENDENCE; DEEP FIELDS AB We present the first measurements of the angular correlation function of galaxies selected in the far (1530 8) and near (2310 angstrom) ultraviolet from the GALEX survey fields overlapping SDSS DR5 in low Galactic extinction regions. The area used covers 120 deg(2) (GALEX Medium Imaging Survey) down to magnitude AB 22, yielding a total of 100,000 galaxies. The mean correlation length is similar to 3.7 +/- 0.6 Mpc, and no significant trend is seen for this value as a function of the limiting apparent magnitude or between the GALEX bands. This estimate is close to that found from samples of blue galaxies in the local universe selected in the visible and similar to that derived at z similar or equal to 3 for LBGs with similar rest frame selection criteria. This result supports models that predict antibiasing of star-forming galaxies at low redshift and brings an additional clue to the downsizing of star formation at z < 1. C1 [Milliard, Bruno; Heinis, Sebastien; Blaizot, Jeremy; Arnouts, Stephane; Donas, Jose; Treyer, Marie; Laget, Michel; Viton, Maurice] Lab Astrophys Marseille, F-13376 Marseille, France. [Heinis, Sebastien; Budavari, Tamas; Szalay, Alex S.; Heckman, Timothy M.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Blaizot, Jeremy] Max Planck Inst Astrophys, D-85748 Garching, Germany. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Wyder, Ted K.; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Seibert, Mark; Small, Todd; Xu, C. K.] CALTECH, Pasadena, CA 91125 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Madore, Barry F.] CALTECH, NASA IPAC Extragalact Database, Pasadena, CA 91125 USA. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Milliard, B (reprint author), Lab Astrophys Marseille, BP 8,Traverse Siphon, F-13376 Marseille, France. NR 63 TC 9 Z9 9 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 494 EP 502 DI 10.1086/524658 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400017 ER PT J AU Heinis, S Milliard, B Arnouts, S Blaizot, J Schiminovich, D Budavari, T Ilbert, O Donas, J Treyer, M Wyder, TK McCracken, HJ Barlow, TA Forster, K Friedman, PG Martin, DC Morrissey, P Neff, SG Seibert, M Small, T Bianchi, L Heckman, TM Lee, YW Madore, BF Rich, RM Szalay, AS Welsh, BY Yi, SK Xu, CK AF Heinis, Sebastien Milliard, Bruno Arnouts, Stephane Blaizot, Jeremy Schiminovich, David Budavari, Tamas Ilbert, Olivier Donas, Jose Treyer, Marie Wyder, Ted K. McCracken, Henry J. Barlow, Tom A. Forster, Karl Friedman, Peter G. Martin, D. Christopher Morrissey, Patrick Neff, Susan G. Seibert, Mark Small, Todd Bianchi, Luciana Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Rich, R. Michael Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung K. Xu, C. K. TI Clustering properties of rest-frame UV-selected galaxies. II. Migration of star formation sites with cosmic time from GALEX and CFHTLS SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE stars : formation; ultraviolet : galaxies ID LYMAN-BREAK GALAXIES; VLT DEEP SURVEY; DIGITAL SKY SURVEY; ULTRAVIOLET LUMINOSITY DENSITY; HALO OCCUPATION DISTRIBUTION; REDSHIFT SURVEY; FORMATION HISTORY; SPECTRAL TYPE; ENVIRONMENTAL DEPENDENCE; PHOTOMETRIC REDSHIFTS AB We analyze the clustering properties of ultraviolet-selected galaxies by using GALEX-SDSS data at z < 0.6 and CFHTLS deep u' imaging at z similar to 1. These data sets provide a unique basis at z similar to 1 which can be directly compared with high-redshift samples built with similar selection criteria. We discuss the dependence of the correlation function parameters (r(0) and delta) on the ultraviolet luminosity, as well as the linear bias evolution. We find that the bias parameter shows a gradual decline from high (b(8) greater than or similar to 2) to low redshift (b8 similar or equal to 0.79(-0.08)(+0.1)). When accounting for the fraction of the star formation activity enclosed in the different samples, our results suggest that the bulk of star formation migrated from high-mass dark matter halos at z > 2 (10(12) M-circle dot <= M-min <= 10(13) M-circle dot, located in high-density regions) to less massive halos at low redshift (M-min <= 10(12) M-circle dot, located in low-density regions). This result extends the "downsizing" picture (shift of the star formation activity from high stellar mass systems at high z to low stellar mass at low z) to the dark matter distribution. C1 [Heinis, Sebastien; Milliard, Bruno; Arnouts, Stephane; Blaizot, Jeremy; Donas, Jose; Treyer, Marie] Lab Astrophys Marseille, F-13376 Marseille 12, France. [Heinis, Sebastien; Budavari, Tamas; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Blaizot, Jeremy] Max Planck Inst Astrophys, D-85748 Garching, Germany. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Ilbert, Olivier] Inst Astron, Honolulu, HI 96822 USA. [Wyder, Ted K.; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Seibert, Mark; Small, Todd; Xu, C. K.] CALTECH, Pasadena, CA 91125 USA. [McCracken, Henry J.] Univ Paris 06, UMR 7095, Inst Astron Paris, F-75014 Paris, France. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Heinis, S (reprint author), Lab Astrophys Marseille, BP8,Traverse Siphon, F-13376 Marseille 12, France. NR 68 TC 24 Z9 24 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 503 EP 511 DI 10.1086/520580 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400018 ER PT J AU Schawinski, K Kaviraj, S Khochfar, S Yoon, SJ Yi, SK Deharveng, JM Boselli, A Barlow, T Conrow, T Forster, K Friedman, PG Martin, DC Morrissey, P Neff, S Schiminovich, D Seibert, M Small, T Wyder, T Bianchi, L Donas, J Heckman, T Lee, YW Madore, B Milliard, B Rich, RM Szalay, A AF Schawinski, K. Kaviraj, S. Khochfar, S. Yoon, S. -J. Yi, S. K. Deharveng, J. -M. Boselli, A. Barlow, T. Conrow, T. Forster, K. Friedman, P. G. Martin, D. C. Morrissey, P. Neff, S. Schiminovich, D. Seibert, M. Small, T. Wyder, T. Bianchi, L. Donas, J. Heckman, T. Lee, Y. -W. Madore, B. Milliard, B. Rich, R. M. Szalay, A. TI The effect of environment on the ultraviolet color-magnitude relation of early-type galaxies SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : elliptical and lenticular, cD; galaxies : evolution; galaxies : formation; galaxies : fundamental parameters ID DIGITAL SKY SURVEY; MORPHOLOGY-DENSITY RELATION; HUBBLE-SPACE-TELESCOPE; CLUSTER MS 1054-03; EARLY DATA RELEASE; ELLIPTIC GALAXIES; EVOLUTION-EXPLORER; STAR-FORMATION; STELLAR POPULATIONS; DISTANT CLUSTERS AB We use GALEX near-UV (NUV) photometry of a sample of early-type galaxies selected in the SDSS (Sloan Digital Sky Survey) to study the UV color-magnitude relation (CMR). NUV-r color is an excellent tracer of even small amounts (similar to 1% mass fraction) of recent (less than or similar to 1 Gyr) star formation, and so the NUV-r CMR allows us to study the effect of environment on the recent star formation history. We analyze a volume-limited sample of 839 visually inspected early-type galaxies in the redshift range 0.05 < z < 0.10 brighter than M-r of -21.5 with any possible emission-line or radio-selected active galactic nuclei (AGNs) removed to avoid contamination. We find that contamination by AGN candidates and late-type interlopers highly bias any study of recent star formation in early-type galaxies and that, after removing those, our lower limit to the fraction of massive early-type galaxies showing signs of recent star formation is roughly 30% +/- 3%. This suggests that residual star formation is common even among the present day early-type galaxy population. We find that the fraction of UV-bright early-type galaxies is 25% higher in low-density environments. However, the density effect is clear only in the lowest density bin. The blue galaxy fraction for the subsample of the brightest early-type galaxies, however, shows a very strong density dependence, in the sense that the blue galaxy fraction is lower in a higher density region. C1 [Schawinski, K.; Kaviraj, S.; Khochfar, S.; Yoon, S. -J.; Yi, S. K.] Univ Oxford, Dept Phys, Oxford OX1 3RH, England. [Yoon, S. -J.; Yi, S. K.; Lee, Y. -W.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Deharveng, J. -M.; Boselli, A.; Donas, J.; Madore, B.] Lab Astrophys Marseille, F-13376 Marseille, France. [Barlow, T.; Conrow, T.; Forster, K.; Friedman, P. G.; Martin, D. C.; Morrissey, P.; Seibert, M.; Small, T.; Wyder, T.] CALTECH, Pasadena, CA 91125 USA. [Neff, S.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Schiminovich, D.] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Bianchi, L.; Heckman, T.; Szalay, A.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Madore, B.] IPAC, Pasadena, CA 91125 USA. [Rich, R. M.] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Schawinski, K (reprint author), Univ Oxford, Dept Phys, Oxford OX1 3RH, England. OI Schawinski, Kevin/0000-0001-5464-0888 NR 66 TC 148 Z9 148 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 512 EP 523 DI 10.1086/516631 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400019 ER PT J AU Boissier, S De Paz, AG Boselli, A Madore, BF Buat, V Cortese, L Burgarella, D Mateos, JC Barlow, TA Forster, K Friedman, PG Martin, DC Morrissey, P Neff, SG Schiminovich, D Seibert, M Small, T Wyder, TK Bianchi, L Donas, J Heckman, TM Lee, YW Milliard, B Rich, RM Szalay, AS Welsh, BY Yi, SK AF Boissier, Samuel De Paz, Armando Gil Boselli, Alessandro Madore, Barry F. Buat, Veronique Cortese, Luca Burgarella, Denis Munoz Mateos, Juan Carlos Barlow, Tom A. Forster, Karl Friedman, Peter G. Martin, D. Christopher Morrissey, Patrick Neff, Susan G. Schiminovich, David Seibert, Mark Small, Todd Wyder, Ted K. Bianchi, Luciana Donas, Jose Heckman, Timothy M. Lee, Young-Wook Milliard, Bruno Rich, R. Michael Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung K. TI Radial variation of attenuation and star formation in the largest late-type disks observed with GALEX SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review DE dust, extinction; galaxies : spiral; infrared : galaxies; ultraviolet : galaxies ID SCULPTOR GROUP GALAXIES; BARRED SPIRAL GALAXIES; H-II REGIONS; CHEMO-SPECTROPHOTOMETRIC EVOLUTION; ULTRAVIOLET LUMINOSITY DENSITY; SPECTRAL ENERGY-DISTRIBUTION; NEUTRAL HYDROGEN; MOLECULAR GAS; VIRGO CLUSTER; STARBURST GALAXIES AB For a sample of 43 nearby, late-type galaxies, we have investigated the radial variation of both the current star formation rate and the dust-induced UV light attenuation. To do this we have cross-correlated IRAS images and GALEX observations for each of these galaxies and compiled observations of the gas (CO and H I) and metal-abundance gradients found in the literature. We find that attenuation correlates with metallicity. We then use the UV profiles, corrected for attenuation, to study several variants of the Schmidt law and conclude that our results are compatible with a simple law similar to the one of Kennicutt extending smoothly to lower surface densities, but with considerable scatter. We do not detect an abrupt break in the UV light at the threshold radius derived from H alpha data (at which the H alpha profile shows a break and beyond which only a few H II regions are usually found). We interpret the H alpha sudden break not as a change in the star formation regime (as often suggested), but as the vanishingly small number of ionizing stars corresponding to low levels of star formation. C1 [Boissier, Samuel; De Paz, Armando Gil; Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Boissier, Samuel; Boselli, Alessandro; Buat, Veronique; Cortese, Luca; Burgarella, Denis; Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille, France. [De Paz, Armando Gil; Munoz Mateos, Juan Carlos] Univ Complutense, Dept Astrofis & CC Atmosfera, E-28040 Madrid, Spain. [Madore, Barry F.] CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. [Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Seibert, Mark; Small, Todd; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Heckman, Timothy M.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Boissier, S (reprint author), Observ Carnegie Inst Washington, 813 Santa Barbara St, Pasadena, CA 91101 USA. EM boissier@ociw.edu; agpaz@ociw.edu; madore@ociw.edu RI Gil de Paz, Armando/J-2874-2016; OI Gil de Paz, Armando/0000-0001-6150-2854; Cortese, Luca/0000-0002-7422-9823 NR 126 TC 154 Z9 155 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 EI 1538-4365 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 524 EP 537 DI 10.1086/516642 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400020 ER PT J AU Thilker, DA Bianchi, L Meurer, G De Paz, AG Boissier, S Madore, BF Boselli, A Ferguson, AMN Munoz-Mateos, JC Madsen, GJ Hameed, S Overzier, RA Forster, K Friedman, PG Martin, DC Morrissey, P Neff, SG Schiminovich, D Seibert, M Small, T Wyder, TK Donas, J Heckman, TM Lee, YW Milliard, B Rich, RM Szalay, AS Welsh, BY Yi, SK AF Thilker, David A. Bianchi, Luciana Meurer, Gerhardt De Paz, Armando Gil Boissier, Samuel Madore, Barry F. Boselli, Alessandro Ferguson, Annette M. N. Munoz-Mateos, Juan Carlos Madsen, Greg J. Hameed, Salman Overzier, Roderik A. Forster, Karl Friedman, Peter G. Martin, D. Christopher Morrissey, Patrick Neff, Susan G. Schiminovich, David Seibert, Mark Small, Todd Wyder, Ted K. Donas, Jose Heckman, Timothy M. Lee, Young-Wook Milliard, Bruno Rich, R. Michael Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung K. TI A search for extended ultraviolet disk (XUV-disk) galaxies in the local universe SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review DE galaxies : evolution; ultraviolet : galaxies ID H-II REGIONS; CHEMO-SPECTROPHOTOMETRIC EVOLUTION; STAR-FORMATION HISTORY; DWARF IRREGULAR GALAXIES; BAND SURFACE PHOTOMETRY; NEARBY SPIRAL GALAXIES; INITIAL MASS FUNCTION; EXTREME OUTER DISK; HIGH-VELOCITY GAS; NEUTRAL HYDROGEN AB We have initiated a search for extended ultraviolet disk (XUV-disk) galaxies in the local universe. Here we compare GALEXUV and visible-NIR images of 189 nearby (D < 40 Mpc) S0-Sm galaxies included in the GALEX Atlas of Nearby Galaxies and present the first catalog of XUV-disk galaxies. We find that XUV-disk galaxies are surprisingly common but have varied relative (UV/optical) extent and morphology. Type 1 objects (greater than or similar to 20% incidence) have structured, UV-bright/optically faint emission features in the outer disk, beyond the traditional star formation threshold. Type 2 XUV-disk galaxies (similar to 10% incidence) exhibit an exceptionally large, UV-bright/optically low surface brightness (LSB) zone having blue UV-K(S) outside the effective extent of the inner, older stellar population, but not reaching extreme galactocentric distance. If the activity occurring in XUV-disks is episodic, a higher fraction of present-day spirals could be influenced by such outer disk star formation. Type 1 disks are associated with spirals of all types, whereas Type 2 XUV-disks are predominantly found in late-type spirals. Type 2 XUV-disks are forming stars quickly enough to double their (currently low) stellar mass in the next Gyr (assuming a constant star formation rate). XUV-disk galaxies of both types are systematically more gas-rich than the general galaxy population. Minor external perturbation may stimulate XUV-disk incidence, at least for Type 1 objects. XUV-disks are the most actively evolving galaxies growing via inside-out disk formation in the current epoch, and may constitute a segment of the galaxy population experiencing significant, continued gas accretion from the intergalactic medium or neighboring objects. C1 [Thilker, David A.; Bianchi, Luciana; Meurer, Gerhardt; Overzier, Roderik A.] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [De Paz, Armando Gil; Munoz-Mateos, Juan Carlos] Univ Complutense Madrid, Dept Astron, Madrid 28040, Spain. [Boissier, Samuel; Boselli, Alessandro; Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille, France. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Ferguson, Annette M. N.] Univ Edinburgh, Royal Observ Edindurgh, Inst Astron, Edinburgh, Midlothian, Scotland. [Madsen, Greg J.] Univ Sydney, Sch Phys A29, Sydney, NSW 2006, Australia. [Hameed, Salman] Hampshire Coll, Coll Astron Dept 5, Amherst, MA 01003 USA. [Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Seibert, Mark; Small, Todd; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Thilker, DA (reprint author), Johns Hopkins Univ, Ctr Astrophys Sci, 3400 N Charles St, Baltimore, MD 21218 USA. EM dthilker@pha.jhu.edu RI Gil de Paz, Armando/J-2874-2016 OI Gil de Paz, Armando/0000-0001-6150-2854 NR 180 TC 195 Z9 196 U1 3 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 538 EP 571 DI 10.1086/523853 PG 34 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400021 ER PT J AU Thilker, DA Boissier, S Bianchi, L Calzetti, D Boselli, A Dale, DA Seibert, M Braun, R Burgarella, D De Paz, AG Helou, G Walter, F Kennicutt, RC Madore, BF Martin, DC Barlow, TA Forster, K Friedman, PG Morrissey, P Neff, SG Schiminovich, D Small, T Wyder, TK Donas, J Heckman, TM Lee, YW Milliard, B Rich, RM Szalay, AS Welsh, BY Yi, SK AF Thilker, David A. Boissier, Samuel Bianchi, Luciana Calzetti, Daniela Boselli, Alessandro Dale, Daniel A. Seibert, Mark Braun, Robert Burgarella, Denis De Paz, Armando Gil Helou, George Walter, Fabian Kennicutt, R. C., Jr. Madore, Barry F. Martin, D. Christopher Barlow, Tom A. Forster, Karl Friedman, Peter G. Morrissey, Patrick Neff, Susan G. Schiminovich, David Small, Todd Wyder, Ted K. Donas, Jose Heckman, Timothy M. Lee, Young-Wook Milliard, Bruno Rich, R. Michael Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung K. TI Ultraviolet and infrared diagnostics of star formation and dust in NGC 7331 SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review DE galaxies : evolution; galaxies : individual (NGC 7331); infrared : galaxies; ultraviolet : galaxies ID NEARBY GALAXIES SURVEY; MULTIBAND IMAGING PHOTOMETER; RADIAL EXTINCTION PROFILES; SPITZER-SPACE-TELESCOPE; VIRGO CLUSTER GALAXIES; LARGE-MAGELLANIC-CLOUD; GLOBAL SCHMIDT LAW; SPIRAL GALAXIES; FORMING GALAXIES; HII-REGIONS AB We present images of NGC 7331 obtained with GALEX and Spitzer, tracing UV and IR signatures of star formation. NGC 7331's morphology at 8-850 mu m is dominated by a central dust ring. This structure is a vigorous site of star formation (hosting one-third of the present activity) but remains inconspicuous in our GALEX UV imagery. Radial profile analysis and photometry for discrete UV- and UV+IR-selected substructures indicate a decline in UV-extinction with increasing galactocentric distance, although highly attenuated star-forming regions can be found throughout the disk. UV- optical surface brightness profiles suggest a recent birthrate parameter (b(8)) that is highest in the outer part of the disk, even though the local star formation intensity peaks in the ring. Bolometric luminosity and UV attenuation are correlated in substructures on 0.4 kpc scales, with a relationship similar to that established for starburst galaxies. The distribution of substructures in L(IR)/L(FUV), L lambda(FUV)/L lambda(NUV) space suggests that the majority of the disk is best characterized by Milky Way-type dust, with the exception of sources in the star-forming ring. As found by Calzetti et al. in M51, the observed 8 and 24 mu m luminosity for substructures in NGC 7331 are correlated, showing a decline in L-v(8 mu m)/L-v(24 mu m) with increasing luminosity. We demonstrate the dependence of L-v(8 mu m)/L-v(24 mu m) on the local extinction-corrected H alpha surface brightness (hence current Sigma(SFR)). A power law of slope 1.64 (1.87) accurately describes the Schmidt-law relation versus Sigma(H2) (Sigma(gas)) for molecular-dominated environments. The same locations show no correlation between Sigma(SFR) and Sigma(H) (I). For atomic-dominated regions above an apparent local star formation threshold, we found a trend for increasing Sigma(SFR) at higher Sigma(H I), although the Schmidt-law correlation with molecular-only surface density persists in areas dominated by atomic gas. C1 [Thilker, David A.; Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Boissier, Samuel; De Paz, Armando Gil; Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Boissier, Samuel; Boselli, Alessandro; Burgarella, Denis; Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille 12, France. [Calzetti, Daniela] Space Telescope Sci Inst, Baltimore, MD 21218 USA. [Dale, Daniel A.] Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. [Seibert, Mark; Martin, D. Christopher; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Morrissey, Patrick; Small, Todd; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Braun, Robert] ASTRON, NL-7990 AA Dwingeloo, Netherlands. [De Paz, Armando Gil] Univ Complutense Madrid, Dept Astrofis, Madrid 28040, Spain. [Helou, George] CALTECH, Pasadena, CA 91101 USA. [Walter, Fabian] Max Planck Inst Astron, D-69117 Heidelberg, Germany. [Kennicutt, R. C., Jr.] Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Lee, Young-Wook] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Thilker, DA (reprint author), Johns Hopkins Univ, Ctr Astrophys Sci, 3400 N Charles St, Baltimore, MD 21218 USA. EM dthilker@pha.jhu.edu RI Gil de Paz, Armando/J-2874-2016 OI Gil de Paz, Armando/0000-0001-6150-2854 NR 108 TC 54 Z9 54 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 EI 1538-4365 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 572 EP 596 DI 10.1086/516646 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400022 ER PT J AU Donas, J Deharveng, JM Rich, RM Yi, SK Lee, YW Boselli, A De Paz, AG Boissier, S Charlot, S Salim, S Bianchi, L Barlow, TA Forster, K Friedman, PG Heckman, TM Madore, BF Martin, DC Milliard, B Morrissey, P Neff, SG Schiminovich, D Seibert, M Small, T Szalay, AS Welsh, BY Wyder, TK AF Donas, Jose Deharveng, Jean-Michel Rich, R. Michael Yi, Sukyoung K. Lee, Young-Wook Boselli, Alessandro De Paz, Armando Gil Boissier, Samuel Charlot, Stephane Salim, Samir Bianchi, Luciana Barlow, Tom A. Forster, Karl Friedman, Peter G. Heckman, Timothy M. Madore, Barry F. Martin, D. Christopher Milliard, Bruno Morrissey, Patrick Neff, Susan G. Schiminovich, David Seibert, Mark Small, Todd Szalay, Alex S. Welsh, Barry Y. Wyder, Ted K. TI GALEX UV color relations for nearby early-type galaxies SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : elliptical and lenticular, cD; galaxies : photometry; galaxies : stellar content; ultraviolet : galaxies ID OLD STELLAR POPULATIONS; ELLIPTIC GALAXIES; EVOLUTION-EXPLORER; STAR-FORMATION; LOCAL UNIVERSE; ULTRAVIOLET; PHOTOMETRY; CLUSTER; SAMPLE; M32 AB We use GALEX/optical photometry to construct color-color relationships for early-type galaxies sorted by morphological type. We have matched objects in the GALEX GR1 public release and the first IR1.1 internal release, with the RC3 early-type galaxies having a morphological type -5.5 <= T < -1.5, with mean error on T < 1.5 and mean error on (B - V)(T) < 0: 05. After visual inspection of each match, we are left with 130 galaxies with reliable GALEX pipeline photometry in the far-UV and near-UV bands. This sample is divided into ellipticals (-5.5 <= T < -3.5) and lenticulars (-3.5 <= T < -1.5). After correction for Galactic extinction, the color-color diagrams FUV-NUV versus (B-V)(Tc) are plotted for the two subsamples. We find a tight anticorrelation between the FUV-NUV and (B-V)(Tc) colors for ellipticals, with the UV color getting bluer when the (B-V)(Tc) gets redder. This relationship very likely is an extension of the color-metallicity relationship in the GALEX NUV band. We suspect that the main source of the correlation is metal line blanketing in the NUV band. The FUV-NUV versus B-V correlation has larger scatter for lenticular galaxies; we speculate that this reflects the presence of low-level star formation. If the latter objects (i.e., those that are blue both in FUV-NUV and in B-V) are interpreted as harboring recent star formation activity, this would be the case for a few percent (similar to 4%) of ellipticals and similar to 15% of lenticulars; this would mean about 10% of early-type galaxies have residual star formation in our full sample of 130 early-type galaxies. We also plot FUV-NUV versus the Mg-2 index and central velocity dispersion. We find a tight anticorrelation between FUV-NUV and the Mg-2 index; we suspect that this reflects blanketing in the NUV band being correlated with overall metallicity. We find a marginal anticorrelation of FUV-V-T with Mg-2 for elliptical galaxies. C1 [Donas, Jose; Deharveng, Jean-Michel; Boselli, Alessandro; Boissier, Samuel; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille 12, France. [Rich, R. Michael; Salim, Samir] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Yi, Sukyoung K.; Lee, Young-Wook] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [De Paz, Armando Gil] Univ Complutense Madrid, Dept Astrofis, Madrid 28040, Spain. [Charlot, Stephane] CNRS, Inst Astrophys Paris, F-75014 Paris, France. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Seibert, Mark; Small, Todd; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Donas, J (reprint author), Lab Astrophys Marseille, Traverse Siphon,Les Trois Lucs,BP 8, F-13376 Marseille 12, France. EM jose.donas@oamp.fr RI Gil de Paz, Armando/J-2874-2016; OI Gil de Paz, Armando/0000-0001-6150-2854; Salim, Samir/0000-0003-2342-7501 NR 41 TC 64 Z9 64 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 597 EP 606 DI 10.1086/516643 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400023 ER PT J AU Ree, CH Lee, YW Yi, SK Yoon, SJ Rich, RM Deharveng, JM Sohn, YJ Kaviraj, S Rhee, J Sheen, YK Schawinski, K Rey, SC Boselli, A Rhee, J Donas, J Seibert, M Wyder, TK Barlow, TA Bianchi, L Forster, K Friedman, PG Heckman, TM Madore, BF Martin, DC Milliard, B Morrissey, P Neff, SG Schiminovich, D Small, T Szalay, AS Welsh, BY AF Ree, Chang H. Lee, Young-Wook Yi, Sukyoung K. Yoon, Suk-Jin Rich, R. Michael Deharveng, Jean-Michel Sohn, Young-Jong Kaviraj, Sugata Rhee, Jonghwan Sheen, Yun-Kyeong Schawinski, Kevin Rey, Soo-Chang Boselli, Alessandro Rhee, Jaehyon Donas, Jose Seibert, Mark Wyder, Ted K. Barlow, Tom A. Bianchi, Luciana Forster, Karl Friedman, Peter G. Heckman, Timothy M. Madore, Barry F. Martin, D. Christopher Milliard, Bruno Morrissey, Patrick Neff, Susan G. Schiminovich, David Small, Todd Szalay, Alex S. Welsh, Barry Y. TI The look-back time evolution of far-ultraviolet flux from the brightest cluster elliptical galaxies at z < 0.2 SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : elliptical and lenticular, cD; galaxies : evolution; galaxies : stellar content; ultraviolet : galaxies ID HORIZONTAL-BRANCH STARS; DIGITAL SKY SURVEY; EVOLVED STELLAR POPULATIONS; METAL-POOR STARS; GLOBULAR-CLUSTERS; UV UPTURN; LUMINOSITY FUNCTION; COMMISSIONING DATA; OMEGA-CENTAURI; MAIN-SEQUENCE AB We present the GALEX UV photometry of the elliptical galaxies in Abell clusters at moderate redshifts (z < 0.2) for the study of the look-back time evolution of the UV upturn phenomenon. The brightest elliptical galaxies (M-r less than or similar to -22) in 12 remote clusters are compared with the nearby giant elliptical galaxies of comparable optical luminosity in the Fornax and Virgo clusters. The sample galaxies presented here appear to be quiescent without signs of massive star formation or strong nuclear activity and show smooth, extended profiles in their UV images, indicating that the far-UV (FUV) light is mostly produced by hot stars in the underlying old stellar population. Compared to their counterparts in nearby clusters, the FUV flux of cluster giant elliptical galaxies at moderate redshifts fades rapidly with similar to 2 Gyr of look-back time, and the observed pace in FUV-V color evolution agrees reasonably well with the prediction from the population synthesis models where the dominant FUV source is hot horizontal-branch stars and their progeny. A similar amount of color spread (similar to 1 mag) in FUV-V exists among the brightest cluster elliptical galaxies at z similar to 0. 1, as observed among the nearby giant elliptical galaxies of comparable optical luminosity. C1 [Ree, Chang H.; Lee, Young-Wook; Yi, Sukyoung K.; Yoon, Suk-Jin; Sohn, Young-Jong; Rhee, Jonghwan; Sheen, Yun-Kyeong; Rhee, Jaehyon] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Lee, Young-Wook] Yale Univ, Dept Astron, New Haven, CT 06511 USA. [Rich, R. Michael; Rhee, Jonghwan] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Deharveng, Jean-Michel; Boselli, Alessandro; Donas, Jose; Milliard, Bruno] Lab Astrophys Marseille, F-13376 Marseille, France. [Kaviraj, Sugata; Schawinski, Kevin] Univ Oxford, Dept Phys, Oxford OX1 3RH, England. [Rey, Soo-Chang] Chungnam Natl Univ, Dept Astron & Space Sci, Taejon 305764, South Korea. [Rhee, Jaehyon; Seibert, Mark; Wyder, Ted K.; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Small, Todd] CALTECH, Pasadena, CA 91125 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. RP Ree, CH (reprint author), Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. EM chr@csa.yonsei.ac.kr; ywlee@csa.yonsei.ac.kr OI Ree, Chang Hee/0000-0001-8986-112X; Schawinski, Kevin/0000-0001-5464-0888 NR 77 TC 28 Z9 28 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 607 EP 618 DI 10.1086/518125 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400024 ER PT J AU Kaviraj, S Schawinski, K Devriendt, JEG Ferreras, I Khochfar, S Yoon, SJ Yi, SK Deharveng, JM Boselli, A Barlow, T Conrow, T Forster, K Friedman, PG Martin, DC Morrissey, P Neff, S Schiminovich, D Seibert, M Small, T Wyder, T Bianchi, L Donas, J Heckman, T Lee, YW Madore, B Milliard, B Rich, RM Szalay, A AF Kaviraj, S. Schawinski, K. Devriendt, J. E. G. Ferreras, I. Khochfar, S. Yoon, S. -J. Yi, S. K. Deharveng, J. -M. Boselli, A. Barlow, T. Conrow, T. Forster, K. Friedman, P. G. Martin, D. C. Morrissey, P. Neff, S. Schiminovich, D. Seibert, M. Small, T. Wyder, T. Bianchi, L. Donas, J. Heckman, T. Lee, Y. -W. Madore, B. Milliard, B. Rich, R. M. Szalay, A. TI UV-optical colors as probes of early-type galaxy evolution SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : elliptical and lenticular, cD; galaxies : evolution; galaxies : formation; galaxies : fundamental parameters ID DIGITAL SKY SURVEY; HUBBLE-SPACE-TELESCOPE; RECENT STAR-FORMATION; STELLAR POPULATION HISTORIES; CLUSTER MS 1054-03; ELLIPTIC GALAXIES; MAGNITUDE RELATION; RICH CLUSTER; ULTRAVIOLET UPTURN; GLOBULAR-CLUSTERS AB We have studied similar to 2100 early-type galaxies in the SDSS DR3 which have been detected by the GALEX Medium Imaging Survey (MIS), in the redshift range 0 < z < 0.11. Combining GALEX UV photometry with corollary optical data from the SDSS, we find that, at a 95% confidence level, at least similar to 30% of galaxies in this sample have UV to optical colors consistent with some recent star formation within the last Gyr. In particular, galaxies with an NUV-r color less than 5.5 are very likely to have experienced such recent star formation, taking into account the possibility of a contribution to NUV flux from the UV upturn phenomenon. We find quantitative agreement between the observations and the predictions of a semianalytical Lambda CDM hierarchical merger model and deduce that early-type galaxies in the redshift range 0 < z < 0.11 have similar to 1%-3% of their stellar mass in stars less than 1 Gyr old. The average age of this recently formed population is similar to 300-500 Myr. We also find that "monolithically" evolving galaxies, where recent star formation can be driven solely by recycled gas from stellar mass loss, cannot exhibit the blue colors (NUV-r < 5: 5) seen in a significant fraction (similar to 30%) of our observed sample. C1 [Kaviraj, S.; Schawinski, K.; Devriendt, J. E. G.; Ferreras, I.; Khochfar, S.; Yoon, S. -J.; Yi, S. K.] Univ Oxford, Dept Phys, Oxford OX1 3RH, England. [Devriendt, J. E. G.] Observ Astron Lyon, F-69561 St Genis Laval, France. [Ferreras, I.] Kings Coll London, Dept Phys, London WC2R 2LS, England. [Yoon, S. -J.; Yi, S. K.; Lee, Y. -W.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Deharveng, J. -M.; Boselli, A.; Donas, J.; Milliard, B.] Lab Astrophys Marseille, F-13376 Marseille, France. [Barlow, T.; Conrow, T.; Forster, K.; Friedman, P. G.; Martin, D. C.; Morrissey, P.; Seibert, M.; Small, T.; Wyder, T.] CALTECH, Pasadena, CA 91125 USA. [Neff, S.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Schiminovich, D.] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Heckman, T.; Szalay, A.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Madore, B.] IPAC, Pasadena, CA 91125 USA. [Rich, R. M.] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Kaviraj, S (reprint author), Univ Oxford, Dept Phys, Oxford OX1 3RH, England. EM yi@yonsei.ac.kr OI Ferreras, Ignacio/0000-0003-4584-3127; Schawinski, Kevin/0000-0001-5464-0888 NR 89 TC 208 Z9 209 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 619 EP 642 DI 10.1086/516633 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400025 ER PT J AU Rey, SC Rich, RM Sohn, ST Yoon, SJ Chung, C Yi, SK Lee, YW Rhee, J Bianchi, L Madore, BF Lee, K Barlow, TA Forster, K Friedman, PG Martin, DC Morrissey, P Neff, SG Schiminovich, D Seibert, M Small, T Wyder, TK Donas, J Heckman, TM Milliard, B Szalay, AS Welsh, BY AF Rey, Soo-Chang Rich, R. Michael Sohn, Sangmo T. Yoon, Suk-Jin Chung, Chul Yi, Sukyoung K. Lee, Young-Wook Rhee, Jaehyon Bianchi, Luciana Madore, Barry F. Lee, Kyungsook Barlow, Tom A. Forster, Karl Friedman, Peter G. Martin, D. Christopher Morrissey, Patrick Neff, Susan G. Schiminovich, David Seibert, Mark Small, Todd Wyder, Ted K. Donas, Jose Heckman, Timothy M. Milliard, Bruno Szalay, Alex S. Welsh, Barry Y. TI GALEX ultraviolet photometry of globular clusters in M31: Three-year results and a catalog SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : individual (M31); galaxies : star clusters; globular clusters : general; ultraviolet : galaxies ID HORIZONTAL-BRANCH STARS; GALAXY-EVOLUTION-EXPLORER; OLD STELLAR POPULATIONS; HUBBLE-SPACE-TELESCOPE; COLOR-MAGNITUDE DIAGRAMS; MILKY-WAY; ELLIPTIC GALAXIES; FAR-ULTRAVIOLET; MAIN-SEQUENCE; CHEMICAL-PROPERTIES AB We present ultraviolet (UV) photometry of M31 globular clusters (GCs) found in 23 Galaxy Evolution Explorer (GALEX) images covering the entirety of M31. We detect 485 and 273 GCs (and GC candidates) in the near-ultraviolet (NUV) and far-ultraviolet (FUV), respectively. The UV properties of GCs have been analyzed using various combinations of UV - optical and optical - optical colors. Comparing M31 data with those of Galactic GCs in the UV with the aid of population models, we find that the age ranges of old GCs in M31 and the Galactic halo are similar. Three metal-rich ([Fe/H] > - 1) GCs in M31 produce significant FUV flux making their FUV - V colors unusually blue for their metallicities. These are thought to be analogs of the two peculiar Galactic GCs, NGC 6388 and NGC 6441, with extended blue HB stars. Based on the models incorporating helium enriched subpopulations in addition to the majority of the population that have a normal helium abundance, we suggest that even small fraction of super-helium-rich subpopulations in GCs can reproduce the observed UV bright metal-rich GCs. Young clusters in M31 show distinct UV and optical properties from GCs in Milky Way. Population models indicate that their typical age is less than similar to 2 Gyr and is consistent with the age derived from the most recent high-quality spectroscopic observations. A large fraction of young GCs have the kinematics of the thin, rapidly rotating disk component. Most GCs with bulge kinematics show old ages. The existence of young GCs on the outskirts of M31 disk suggests the occurrence of a significant recent star formation in the thin-disk of M31. We detect 12 (10) intermediate-age GC candidates in NUV (FUV) identified by previous spectroscopic observations. On the basis of comparing our UV photometry to population models, we suggest that some of spectroscopically identified intermediate-age GCs may not be truly intermediate in age, but rather older GCs that possess developed HB stars which contribute to enhanced UV flux as well as Balmer lines. C1 [Rey, Soo-Chang; Lee, Kyungsook] Chungnam Natl Univ, Dept Astron & Space Sci, Taejon 305764, South Korea. [Rey, Soo-Chang; Sohn, Sangmo T.; Yoon, Suk-Jin; Chung, Chul; Yi, Sukyoung K.; Lee, Young-Wook; Rhee, Jaehyon] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Rey, Soo-Chang; Rhee, Jaehyon; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Seibert, Mark; Small, Todd; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Sohn, Sangmo T.] Korea Astron & Space Sci Inst, Taejon 305348, South Korea. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Donas, Jose; Milliard, Bruno] Astrophys Lab, F-13376 Marseille 12, France. [Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Rey, SC (reprint author), Chungnam Natl Univ, Dept Astron & Space Sci, Taejon 305764, South Korea. EM screy@cnu.ac.kr NR 98 TC 36 Z9 36 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 643 EP 658 DI 10.1086/516649 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400026 ER PT J AU Bianchi, L Rodriguez-Merino, L Viton, M Laget, M Efremova, B Herald, J Conti, A Shiao, B De Paz, AG Salim, S Thakar, A Friedman, PG Rey, SC Thilker, D Barlow, TA Budavari, T Donas, J Forster, K Heckman, TM Lee, YW Madore, BF Martin, DC Milliard, B Morrissey, P Neff, SG Rich, RM Schiminovich, D Seibert, M Small, T Szalay, AS Wyder, TK Welsh, BY Yi, SK AF Bianchi, Luciana Rodriguez-Merino, Lino Viton, Maurice Laget, Michel Efremova, Boryana Herald, James Conti, Alberto Shiao, Bernie De Paz, Armando Gil Salim, Samir Thakar, A. Friedman, Peter G. Rey, Soo-Chang Thilker, David Barlow, Tom A. Budavari, Tamas Donas, Jose Forster, Karl Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Martin, D. Christopher Milliard, Bruno Morrissey, Patrick Neff, Susan G. Rich, R. Michael Schiminovich, David Seibert, Mark Small, Todd Szalay, Alex S. Wyder, Ted K. Welsh, Barry Y. Yi, Sukyoung K. TI Statistical properties of the GALEX-SDSS matched source catalogs, and classification of the UV sources SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxy : stellar content; quasars : general; stars : statistics; surveys; ultraviolet : stars; white dwarfs ID DIGITAL SKY SURVEY; GALAXY-EVOLUTION-EXPLORER; WHITE-DWARFS; EFFECTIVE TEMPERATURES; DATA RELEASE; HOT STARS; ULTRAVIOLET; ATMOSPHERES; CALIBRATION; SPECTRA AB We use the Galaxy Evolution Explorer (GALEX) Medium and All-Sky Imaging Survey (MIS and AIS) data from the first public data release (GR1), matched to the Sloan Digital Sky Survey (SDSS) DR3 catalog, to perform source classification. The GALEX surveys provide photometry in far-and near-UV bands and the SDSS in five optical bands (u, g, r, i, z). The GR1/DR3 overlapping areas are 363 (86) deg(2) for the GALEX AIS (MIS), for sources within the 0.5 degrees central area of the GALEX fields. Our sample covers mostly vertical bar b vertical bar > 30 degrees Galactic latitudes. We present statistical properties of the GALEX-SDSS matched sources catalog, containing > 2; 106 objects detected in at least one UV band. We classify the matched sources by comparing the seven-band photometry to model colors constructed for different classes of astrophysical objects. For sources with photometric errors < 0.3 mag, the corresponding typical AB-magnitude limits are m(FUV) similar to 21.5, m(NUV) similar to 22.5 for AIS, and m(FUV) similar to 24, mNUV similar to 24: 5 for MIS. At AIS depth, the number of Galactic and extragalactic objects are comparable, but the latter predominate in the MIS. On the basis of our stellar models, we estimate the GALEX surveys detect hot white dwarfs throughout the Milky Way halo (down to a radius of 0.04 R-circle dot at MIS depth), providing an unprecedented improvement in the Galactic WD census. Their observed surface density is consistent with Milky Way model predictions. We also select low-redshift QSO candidates, extending the known QSO samples to lower magnitudes, and providing z approximate to 1 candidates for detailed z approximate to 1 follow-up investigations. SDSS optical spectra available for a large subsample confirm the classification for the photometrically selected candidates with 97% purity for single hot stars, approximate to 45% (AIS) or 31% (MIS) for binaries containing a hot star and a cooler companion, and about 85% for QSOs. C1 [Bianchi, Luciana; Rodriguez-Merino, Lino; Efremova, Boryana; Herald, James; Thakar, A.; Thilker, David; Budavari, Tamas; Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Viton, Maurice; Laget, Michel; Donas, Jose; Milliard, Bruno] Astrophys Lab, F-13376 Marseille 12, France. [Conti, Alberto; Shiao, Bernie] Space Telescope Sci Inst, Baltimore, MD 21218 USA. [De Paz, Armando Gil] Univ Complutense, E-28040 Madrid, Spain. [Salim, Samir; Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Friedman, Peter G.; Barlow, Tom A.; Forster, Karl; Martin, D. Christopher; Morrissey, Patrick; Schiminovich, David; Seibert, Mark; Small, Todd; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Rey, Soo-Chang] Chungnam Natl Univ, Dept Astron & Space Sci, Taejon 305764, South Korea. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Bianchi, L (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. EM bianchi@pha.jhu.edu OI Conti, Alberto/0000-0002-3773-2753; Salim, Samir/0000-0003-2342-7501 NR 36 TC 58 Z9 58 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 659 EP 672 DI 10.1086/516648 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400027 ER PT J AU Welsh, BY Wheatley, JM Seibert, M Browne, SE West, AA Siegmund, OHW Barlow, TA Forster, K Friedman, PG Martin, DC Morrissey, P Small, T Wyder, T Schiminovich, D Neff, S Rich, RM AF Welsh, Barry Y. Wheatley, Jonathan M. Seibert, Mark Browne, Stanley E. West, Andrew A. Siegmund, Oswald H. W. Barlow, Tom A. Forster, Karl Friedman, Peter G. Martin, D. Christopher Morrissey, Patrick Small, Todd Wyder, Ted Schiminovich, David Neff, Susan Rich, R. Michael TI The detection of M dwarf UV flare events in the GALEX data archives SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE stars : variables : other; ultraviolet : stars ID DIGITAL SKY SURVEY; XMM-NEWTON; X-RAY; EXTREME-ULTRAVIOLET; INFRARED-SPECTRA; DATA RELEASE; COOL STARS; AD LEONIS; DME STARS; SPECTROSCOPY AB We present the preliminary results from implementing a new software tool that enables inspection of time-tagged photon data for the astronomical sources contained within individual GALEX ultraviolet (UV) images of the sky. We have inspected the photon data contained within 1802 GALEX images to reveal rapid, short-term (less than or similar to 500 s) UV source variability in the form of stellar "flares.'' The mean associated change in near-UV (NUV) magnitude due to this flaring activity is 2: 7 +/- 0: 3 mag. A list of 49 new UV variable star candidates is presented, together with their associated Sloan Digital Sky Survey (SDSS) photometric magnitudes. From these data we can associate the main source of these UV flare events with magnetic activity on M dwarf stars. Photometric parallaxes have been determined for 32 of these sources, placing them at distances ranging from approximately 25 to 1000 pc. The average UV flare energy for these flare events is 2.5 x 10(30) ergs, which is of a similar energy to that of U-band, X-ray, and EUV flares observed on many local M dwarf stars. We have found that stars of classes M0 toM5 flare with energies spanning a far larger range and with an energy approximately 5 times greater than those of later (M6 to M8) spectral type. C1 [Welsh, Barry Y.; Wheatley, Jonathan M.; Browne, Stanley E.; Siegmund, Oswald H. W.] Univ Calif Berkeley, Space Sci Lab, Expt Astrophys Grp, Berkeley, CA 94720 USA. [Seibert, Mark; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Small, Todd; Wyder, Ted] CALTECH, Pasadena, CA 91125 USA. [West, Andrew A.] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Neff, Susan] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Welsh, BY (reprint author), Univ Calif Berkeley, Space Sci Lab, Expt Astrophys Grp, 7 Gauss Way, Berkeley, CA 94720 USA. EM bwelsh@ssl.berkeley.edu; wheat@ssl.berkeley.edu RI West, Andrew/H-3717-2014 NR 30 TC 29 Z9 29 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 673 EP 681 DI 10.1086/516640 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400028 ER PT J AU Morrissey, P Conrow, T Barlow, TA Small, T Seibert, M Wyder, TK Budavari, T Arnouts, S Friedman, PG Forster, K Martin, DC Neff, SG Schiminovich, D Bianchi, L Donas, J Heckman, TM Lee, YW Madore, BF Milliard, B Rich, M Szalay, AS Welsh, BY Yi, SK AF Morrissey, Patrick Conrow, Tim Barlow, Tom A. Small, Todd Seibert, Mark Wyder, Ted K. Budavari, Tamas Arnouts, Stephane Friedman, Peter G. Forster, Karl Martin, D. Christopher Neff, Susan G. Schiminovich, David Bianchi, Luciana Donas, Jose Heckman, Timothy M. Lee, Young-Wook Madore, Barry F. Milliard, Bruno Rich, Michael Szalay, Alex S. Welsh, Barry Y. Yi, Sukyoung K. TI The calibration and data products of GALEX SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE space vehicles; surveys; telescopes; ultraviolet : general ID GALAXY-EVOLUTION-EXPLORER; SPECTROPHOTOMETRIC STANDARDS; FAR-ULTRAVIOLET; SKY-SURVEY; PERFORMANCE; STARS AB We describe the calibration status and data products pertaining to the GR2 and GR3 data releases of the Galaxy Evolution Explorer (GALEX). These releases have identical pipeline calibrations that are significantly improved over the GR1 data release. GALEX continues to survey the sky in the far-ultraviolet (FUV, similar to 154nm) and near-ultraviolet (NUV, similar to 232 nm) bands, providing simultaneous imaging with a pair of photon-counting, microchannel plate, delay line readout detectors. These 1.25 degrees field of view detectors are well suited to ultraviolet observations because of their excellent red rejection and negligible background. A dithered mode of observing and photon list output pose complex requirements on the data processing pipeline, entangling detector calibrations, and aspect reconstruction algorithms. Recent improvements have achieved photometric repeatability of 0.05 and 0.03 m(AB) in the FUV and NUV, respectively. We have detected a long-term drift of order 1% FUV and 6% NUV over the mission. Astrometric precision is of order 0.5 '' rms in both bands. In this paper we provide the GALEX user with a broad overview of the calibration issues likely to be confronted in the current release. Improvements are likely as the GALEX mission continues into an extended phase with a healthy instrument, no consumables, and increased opportunities for guest investigations. C1 [Morrissey, Patrick; Conrow, Tim; Barlow, Tom A.; Small, Todd; Wyder, Ted K.; Friedman, Peter G.; Forster, Karl; Martin, D. Christopher] CALTECH, Pasadena, CA 91125 USA. [Seibert, Mark; Madore, Barry F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Budavari, Tamas; Heckman, Timothy M.; Szalay, Alex S.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Arnouts, Stephane; Donas, Jose; Milliard, Bruno] Astrophys Lab, F-13376 Marseille 12, France. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. [Bianchi, Luciana] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. [Lee, Young-Wook; Yi, Sukyoung K.] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. [Rich, Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Welsh, Barry Y.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Morrissey, P (reprint author), CALTECH, MC 405-47,1200 E California Blvd, Pasadena, CA 91125 USA. NR 18 TC 462 Z9 463 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2007 VL 173 IS 2 BP 682 EP 697 DI 10.1086/520512 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258BM UT WOS:000252843400029 ER PT J AU Bogomolov, VV Castrucci, F Comtois, JM Damann, V Davis, JR Duncan, JM Johnston, SL Gray, GW Grigoriev, AI Koike, Y Kuklinski, P Matveyev, VP Morgun, VV Pochuev, VI Sargsyan, AE Shimada, K Straube, U Tachibana, S Voronkov, YV Williams, RS AF Bogomolov, Valery V. Castrucci, Filippo Comtois, Jean-Marc Damann, Volker Davis, Jeffrey R. Duncan, J. Michael Johnston, Smith L. Gray, Gary W. Grigoriev, Anatoly I. Koike, Yu Kuklinski, Paul Matveyev, Vladimir P. Morgun, Valery V. Pochuev, Vladimir I. Sargsyan, Ashot E. Shimada, Kazuhito Straube, Ulrich Tachibana, Shoichi Voronkov, Yuri V. Williams, Richard S. TI International Space Station medical standards and certification for space flight participants SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE space tourism; space medicine; commercial spaceflight; medical certification; international cooperation AB Introduction: The medical community of the International Space Station (ISS) has developed joint medical standards and evaluation requirements for Space Flight Participants ("space tourists") which are used by the ISS medical certification board to determine medical eligibility of individuals other than professional astronauts (cosmonauts) for short-duration space flight to the ISS. These individuals are generally fare-paying passengers without operational responsibilities. Material and Context: By means of this publication, the medical standards and evaluation requirements for the ISS Space Flight Participants are offered to the aerospace medicine and commercial spaceflight communities for reference purposes. It is emphasized that the criteria applied to the ISS spaceflight participant candidates are substantially less stringent than those for professional astronauts and/or crewmembers of visiting and long-duration missions to the ISS. Conclusions: These medical standards are released by the government space agencies to facilitate the development of robust medical screening and medical risk assessment approaches in the context of the evolving commercial human spaceflight industry. C1 Wyle Labs Life Sci Grp, Houston, TX 77058 USA. NASA, Washington, DC 20546 USA. RP Sargsyan, AE (reprint author), Wyle Labs Life Sci Grp, 1290 Hercules Ave,Ste 103, Houston, TX 77058 USA. EM ashot.sargsyan-1@nasa.gov NR 0 TC 13 Z9 13 U1 0 U2 6 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD DEC PY 2007 VL 78 IS 12 BP 1162 EP 1169 DI 10.3357/ASEM.2175.2007 PG 8 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 237EF UT WOS:000251355700012 PM 18064923 ER PT J AU Sibonga, JD Evans, HJ Sung, HG Spector, ER Lang, TF Oganov, VS Bakulin, AV Shackelford, LC LeBlanc, AD AF Sibonga, J. D. Evans, H. J. Sung, H. G. Spector, E. R. Lang, T. F. Oganov, V. S. Bakulin, A. V. Shackelford, L. C. LeBlanc, A. D. TI Recovery of spaceflight-induced bone loss: Bone mineral density after long-duration missions as fitted with an exponential function SO BONE LA English DT Article DE cosmonauts; astronauts; bone densitometry; mathematical function; mechanical unloading ID MANNED SKYLAB MISSION; SPACE-FLIGHT; MUSCLE STRENGTH; BED REST; RESORPTION; COSMONAUTS; EXCRETION; MARKERS; BALANCE; MASS AB The loss of bone mineral in NASA astronauts during spaceflight has been investigated throughout the more than 40 years of space travel. Consequently, it is a medical requirement at NASA Johnson Space Center (JSC) that changes in bone mass be monitored in crew members by measuring bone mineral density (BMD), with dual-energy X-ray absorptiometry (DXA) before and after flight, of astronauts who serve on long-duration missions (4-6 months). We evaluated this repository of medical data to track whether there is recovery of bone mineral that was lost during spaceflight. Our analysis was supplemented by BMD data from cosmonauts (by convention, a space traveler formally employed by the Russia Aviation and Space Agency or by the previous Soviet Union) who had also flown on long-duration missions. Data from a total of 45 individual crew members a small number of whom flew on more than one mission - were used in this analysis. Changes in BMD (between 56 different sets of pre- and postflight measurements) were Plotted as a function of time (days after landing). Plotted BMD changes were fitted to an exponential mathematical function that estimated: (i) BMD change on landing day (day 0) and (ii) the number of days after landing when 50% of the lost bone would be recovered ("50% recovery time") in the lumbar spine, trochanter, pelvis, femoral neck and calcaneus. In sum, averaged losses of bone mineral after long-duration spaceflight ranged between 2% and 9% across all sites with our recovery model predicting a 50% restoration of bone loss for all sites to be within 9 months. (C) 2007 Elsevier Inc. All rights reserved. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. [Sibonga, J. D.; LeBlanc, A. D.] Univ Space Res Assoc, Div Space Life Sci, Houston, TX USA. [Evans, H. J.] Wyle Labs, Houston, TX USA. [Oganov, V. S.; Bakulin, A. V.] Russian Acad Sci, Inst Biomed Problems, Moscow, Russia. [Shackelford, L. C.] NASA, Johnson Space Ctr, Human Adaptat & Countermeasures Div, Houston, TX USA. [Lang, T. F.] Univ Calif San Francisco, Dept Radiol, San Francisco, CA 94143 USA. [Sung, H. G.] Google Inc, Mountain View, CA USA. RP Sibonga, JD (reprint author), NASA, Lyndon B Johnson Space Ctr, NASA Pkwy,Mail Code SK-272, Houston, TX 77058 USA. RI Lang, Thomas/B-2685-2012 OI Lang, Thomas/0000-0002-3720-8038 NR 22 TC 89 Z9 96 U1 1 U2 21 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 8756-3282 J9 BONE JI Bone PD DEC PY 2007 VL 41 IS 6 BP 973 EP 978 DI 10.1016/j.bone.2007.08.022 PG 6 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 240DO UT WOS:000251567600008 PM 17931994 ER PT J AU Gopalswamy, N Ramesh, R AF Gopalswamy, N. Ramesh, R. TI Untitled SO BULLETIN OF THE ASTRONOMICAL SOCIETY OF INDIA LA English DT Editorial Material C1 [Gopalswamy, N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Ramesh, R.] Indian Inst Astrophys, Bangalore 560034, Karnataka, India. RP Gopalswamy, N (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Gopalswamy, Nat/D-3659-2012 NR 0 TC 0 Z9 0 U1 0 U2 1 PU INDIAN INST ASTROPHYSICS PI BANGALORE PA G C ANUPAMA EDITOR, BANGALORE, 560 034, INDIA SN 0304-9523 J9 B ASTRON SOC INDIA JI Bull. Astron. Soc. India. PD DEC PY 2007 VL 35 IS 4 BP 417 EP 418 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 290ZS UT WOS:000255162700002 ER PT J AU Goericke, R Venrick, E Koslow, T Sydeman, WJ Schwing, FB Bograd, SJ Peterson, WT Emmett, R Lara, JRL Castro, GTG Valdez, JG Hyrenbach, KD Bradley, RW Weise, MJ Harvey, JT Collins, C Lo, NCH AF Goericke, Ralf Venrick, Elizabeth Koslow, Tony Sydeman, William J. Schwing, Franklin B. Bograd, Steven J. Peterson, William T. Emmett, Robert Ruben Lara Lara, J. To Gaxiola Castro, Gilber Valdez, Jose Gomez Hyrenbach, K. David Bradley, Russel W. Weise, Michael J. Harvey, James T. Collins, Curtis Lo, Nancy C. H. TI The state of the California Current, 2006-2007: Regional and local processes dominate SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article ID LIONS ZALOPHUS-CALIFORNIANUS; CURRENT SYSTEM; MARINE BIRDS; PACIFIC; DIET; ABUNDANCE AB The state of the California Current System (CCS) between Ore.-on and Baja California is summarized in this report, covering spring 2006 to spring 2007, Observations reported here are based on contributions from various ocean observing programs along the West Coast of North America. Basin-scale indicators were variable or neutral over the last year. This indeterminate forcing was reflected in conditions in the CCS where no coherent patterns emerged, i.e., no single "state" could be ascribed to the system. Rather, regional or local processes dominated observed patterns. Similar to last year, delayed upwelling off Ore-on and central California dramatically affected higher trophic levels: euphausiid recruitment was delayed and as a likely consequence seabird productivity off Central California was extremely depressed. For example, Cassin's auklet had a complete reproductive failure, similar to 2006. Observations during the spring of 2007 demonstrate that these patterns were ephemeral since upwelling was normal and seabird productivity improved. Off southern and Baja California, upwelling-favorable winds were also weak or delayed during 2006, but biological consequences appear to have been relatively minor. C1 [Goericke, Ralf; Venrick, Elizabeth; Koslow, Tony] Univ Calif San Diego, Scripps Inst Oceanog, Integrat Oceanog Div, La Jolla, CA 92093 USA. [Sydeman, William J.] Farallon Inst Adv Ecosyst Res, Petaluma, CA 94975 USA. [Schwing, Franklin B.; Bograd, Steven J.] SW Fisheries Sci Ctr, Div Environm Res, NOAA Fisheries, Pacific Grove, CA 93950 USA. [Peterson, William T.; Emmett, Robert] Hatfield Marine Sci Ctr, NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Newport, OR 97365 USA. [Bradley, Russel W.] PRBO Conservat Sci, Marine Ecol Div, Petaluma, CA 94954 USA. [Hyrenbach, K. David] Duke Univ, Marine Lab, Duke Ctr Marine Conservat, Beaufort, NC 28516 USA. [Valdez, Jose Gomez] Ctr Invest Cient & Educ Super Ensenada, Dept Oceanog Fis, Ensenada 22866, Baja California, Mexico. [Ruben Lara Lara, J.; To Gaxiola Castro, Gilber] Ctr Invest Cient & Educ Super Ensenada, Dept Oceanog Biol, Ensenada 22860, Baja California, Mexico. [Weise, Michael J.] Univ Calif Santa Cruz, Ctr Ocean Hlth, Dept Ecol & Evolutionary Biol, Santa Cruz, CA 95060 USA. [Harvey, James T.] Moss Landing Marine Labs, Moss Landing, CA 95039 USA. [Collins, Curtis] Naval Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. [Lo, Nancy C. H.] SW Fisheries Sci Ctr, NOAA Fisheries, La Jolla, CA 92038 USA. RP Goericke, R (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Integrat Oceanog Div, La Jolla, CA 92093 USA. EM rgoericke@ucsd.edu NR 36 TC 33 Z9 34 U1 0 U2 4 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 USA SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD DEC PY 2007 VL 48 BP 33 EP 66 PG 34 WC Fisheries SC Fisheries GA 313WG UT WOS:000256770100003 ER PT J AU Hansen, J Sato, M Ruedy, R Kharecha, P Lacis, A Miller, R Nazarenko, L Lo, K Schmidt, GA Russell, G Aleinov, I Bauer, S Baum, E Cairns, B Canuto, V Chandler, M Cheng, Y Cohen, A Del Genio, A Faluvegi, G Fleming, E Friend, A Hall, T Jackman, C Jonas, J Kelley, M Kiang, NY Koch, D Labow, G Lerner, J Menon, S Novakov, T Oinas, V Perlwitz, J Perlwitz, J Rind, D Romanou, A Schmunk, R Shindell, D Stone, P Sun, S Streets, D Tausnev, N Thresher, D Unger, N Yao, M Zhang, S AF Hansen, J. Sato, M. Ruedy, R. Kharecha, P. Lacis, A. Miller, R. Nazarenko, L. Lo, K. Schmidt, G. A. Russell, G. Aleinov, I. Bauer, S. Baum, E. Cairns, B. Canuto, V. Chandler, M. Cheng, Y. Cohen, A. Del Genio, A. Faluvegi, G. Fleming, E. Friend, A. Hall, T. Jackman, C. Jonas, J. Kelley, M. Kiang, N. Y. Koch, D. Labow, G. Lerner, J. Menon, S. Novakov, T. Oinas, V. Perlwitz, Ja. Perlwitz, Ju. Rind, D. Romanou, A. Schmunk, R. Shindell, D. Stone, P. Sun, S. Streets, D. Tausnev, N. Thresher, D. Unger, N. Yao, M. Zhang, S. TI Climate simulations for 1880-2003 with GISS modelE SO CLIMATE DYNAMICS LA English DT Review ID 20TH-CENTURY TEMPERATURE-CHANGE; SEA-SURFACE TEMPERATURE; OCEAN-ATMOSPHERE MODEL; STRATOSPHERIC OZONE; UNITED-STATES; BLACK CARBON; SOLAR-RADIATION; TROPOSPHERIC TEMPERATURE; HYDROLOGICAL CYCLE; HISTORICAL CHANGES AB We carry out climate simulations for 1880-2003 with GISS modelE driven by ten measured or estimated climate forcings. An ensemble of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together. We compare side-by-side simulated climate change for each forcing, all forcings, observations, unforced variability among model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all forcings are due to model deficiencies, inaccurate or incomplete forcings, and imperfect observations. Although there are notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations of future climate change. By using a fixed well-documented model and accurately defining the 1880-2003 forcings, we aim to provide a benchmark against which the effect of improvements in the model, climate forcings, and observations can be tested. Principal model deficiencies include unrealistically weak tropical El Nino-like variability and a poor distribution of sea ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. Greatest uncertainties in the forcings are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Earth Inst, New York, NY USA. Sigma Space Partners LLC, New York, NY USA. Columbia Univ, Dept Earth & Environm Sci, New York, NY USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA. Clean Air Task Force, Boston, MA USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Orme Merisiers, Lab Sci Climat & Environm, Gif Sur Yvette, France. Yale Univ, Dept Geol, New Haven, CT USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. MIT, Cambridge, MA 02139 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Hansen, J (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM jhansen@giss.nasa.gov RI Perlwitz, Judith/B-7201-2008; Del Genio, Anthony/D-4663-2012; Shindell, Drew/D-4636-2012; Lacis, Andrew/D-4658-2012; Schmidt, Gavin/D-4427-2012; Miller, Ron/E-1902-2012; Sun, Shan/H-2318-2015; Unger, Nadine/M-9360-2015; Jackman, Charles/D-4699-2012; Bauer, Susanne/P-3082-2014 OI Streets, David/0000-0002-0223-1350; Perlwitz, Judith/0000-0003-4061-2442; Del Genio, Anthony/0000-0001-7450-1359; Schmidt, Gavin/0000-0002-2258-0486; Schmunk, Robert/0000-0002-1897-6509; Cairns, Brian/0000-0002-1980-1022; NR 152 TC 142 Z9 150 U1 2 U2 39 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0930-7575 EI 1432-0894 J9 CLIM DYNAM JI Clim. Dyn. PD DEC PY 2007 VL 29 IS 7-8 BP 661 EP 696 DI 10.1007/s00382-007-0255-8 PG 36 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 225JX UT WOS:000250515300001 ER PT J AU Dai, A Lin, X Hsu, KL AF Dai, Aiguo Lin, Xin Hsu, Kuo-Lin TI The frequency, intensity, and diurnal cycle of precipitation in surface and satellite observations over low- and mid-latitudes SO CLIMATE DYNAMICS LA English DT Article ID ARTIFICIAL NEURAL-NETWORKS; GLOBAL PRECIPITATION; TROPICAL RAINFALL; THUNDERSTORM FREQUENCIES; PERSIANN SYSTEM; TRMM SATELLITE; UNITED-STATES; VARIABILITY; INFORMATION; CLIMATOLOGY AB Global precipitation data sets with high spatial and temporal resolution are needed for many applications, but they were unavailable before the recent creation of several such satellite products. Here, we evaluate four different satellite data sets of hourly or 3-hourly precipitation (namely CMORPH, PERSIANN, TRMM 31342 and a microwave-only product referred to as MI) by comparing the spatial patterns in seasonal mean precipitation amount, daily precipitation frequency and intensity, and the diurnal and semidiurnal cycles among them and with surface synoptic weather reports. We found that these high-resolution products show spatial patterns in seasonal mean precipitation amount comparable to other monthly products for the low- and mid-latitudes, and the mean daily precipitation frequency and intensity maps are similar among these pure satellite-based precipitation data sets and consistent with the frequency derived using weather reports over land. The satellite data show that spatial variations in mean precipitation amount come largely from precipitation frequency rather than intensity, and that the use of satellite infrared (IR) observations to improve sampling does not change the mean frequency, intensity and the diurnal cycle significantly. Consistent with previous studies, the satellite data show that sub-daily variations in precipitation are dominated by the 24-h cycle, which has an afternoon-evening maximum and mean-to-peak amplitude of 30-100% of the daily mean in precipitation amount over most land areas during summer. Over most oceans, the 24-h harmonic has a peak from midnight to early morning with an amplitude of 10-30% during both winter and summer. These diurnal results are broadly consistent with those based on the weather reports, although the time of maximum in the satellite precipitation is a few hours later (especially for TRMM and PERSIANN) than that in the surface observations over most land and ocean, and it is closer to the phase of showery precipitation from the weather reports. The TRMM and PERSIANN precipitation shows a spatially coherent time of maximum around 03000600 local solar time (LST) for a weak (amplitude <20%) semi-diumal (12-h) cycle over most mid- to high-latitudes, comparable to 0400-0600 LST in the surface data. The satellite data also confirm the notion that the diurnal cycle of precipitation amount comes mostly from its frequency rather than its intensity over most low and mid-latitudes, with the intensity has only about half of the strength of the diurnal cycle in the frequency and amount. The results suggest that these relatively new precipitation products can be useful for many applications. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Baltimore, MD 21201 USA. Univ Calif Irvine, Irvine, CA USA. RP Dai, A (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM adai@ucar.edu RI Dai, Aiguo/D-3487-2009 NR 36 TC 92 Z9 102 U1 0 U2 15 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD DEC PY 2007 VL 29 IS 7-8 BP 727 EP 744 DI 10.1007/s00382-007-0260-y PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 225JX UT WOS:000250515300004 ER PT J AU Raju, IS Glaessgen, EH Mason, BH Krishnarnurthy, T Davila, CG AF Raju, I. S. Glaessgen, E. H. Mason, B. H. Krishnarnurthy, T. Davila, C. G. TI Structural analysis of the right rear lug of American Airlines flight 587 SO CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES LA English DT Article ID PROGRESSIVE DAMAGE MODEL; LAMINATED COMPOSITES AB A detailed finite element analysis of the right rear lug of the American Airlines Flight 5 87 - Airbus A300-600R was performed as part of the National Transportation Safety Board's failure investigation of the accident that occurred on November 12, 2001. The loads experienced by the right rear lug were evaluated using global models of the vertical tail, local models near the right, rear lug, and a global-local analysis procedure. The right rear lug was analyzed using two modeling approaches. In the first approach, solid-shell type modeling was used, and in the second approach, layered-shell type modeling was used. The solid-shell and the layered-shell modeling approaches were used in progressive failure analyses (PFA) to determine the load, mode, and location of failure in the right rear lug under loading representative of an Airbus certification test conducted in 1985 (the 1985-certification test). Both analyses were in excellent agreement with each other on the predicted failure loads, failure mode, and location of failure. The solid-shell type modeling was then used to analyze both a subcomponent test conducted by Airbus in 2003 (the 2003 -subcomponent test) and the accident condition. Excellent agreement was observed between the analyses and the observed failures in both cases. The moment, M, (moment about the fuselage longitudinal axis), had significant effect on the failure load of the lugs. Higher absolute values of M., gave lower failure loads. The predicted load, mode, and location of the failure of the 19 85 -certification test, 2003 -subcomponent test, and the accident condition are in very good agreement. This agreement suggests that the 1985 -certification and 2003 -subcomponent tests represent the accident condition accurately. The failure mode of the right rear lug for the 19 85 -certification test, 2003-subcomponent test, and the accident load case was identified as a cleavage-type failure. For the accident case, the predicted failure load for the right rear lug from the PFA was greater than 1.98 times the limit load of the lugs. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Raju, IS (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. RI Davila, Carlos/D-8559-2011 NR 23 TC 3 Z9 3 U1 0 U2 1 PU TECH SCIENCE PRESS PI NORCROSS PA 6825 JIMMY CARTER BLVD, STE 1850, NORCROSS, GA 30071 USA SN 1526-1492 J9 CMES-COMP MODEL ENG JI CMES-Comp. Model. Eng. Sci. PD DEC PY 2007 VL 22 IS 1 BP 1 EP 30 PG 30 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 230WS UT WOS:000250907600001 ER PT J AU Santa, KJ Chao, BH Sunderland, PB Urban, DL Stocker, DP Axelbaum, RL AF Santa, K. J. Chao, B. H. Sunderland, P. B. Urban, D. L. Stocker, D. P. Axelbaum, R. L. TI Radiative extinction of gaseous spherical diffusion flames in microgravity SO COMBUSTION AND FLAME LA English DT Article DE extinction; microgravity; laminar diffusion flames; CFD; thin-filament pyrometry ID OSCILLATORY EXTINCTION; COMPUTATION; COMBUSTION AB Radiative extinction of spherical diffusion flames was investigated experimentally and numerically. The experiments involved microgravity spherical diffusion flames burning ethylene and propane at 0.98 bar. Both normal (fuel flowing into oxidizer) and inverse (oxidizer flowing into fuel) flames were studied, with nitrogen supplied to either the fuel or the oxygen. Flame conditions were chosen to ensure that the flames extinguished within the 2.2 s of available test time; thus extinction occurred during unsteady flame conditions. Diagnostics included color video and thin-filament pyrometry. The computations, which simulated flow from a porous sphere into a quiescent environment, included detailed chemistry, transport, and radiation and yielded transient results. Radiative extinction was observed experimentally and simulated numerically. Extinction time, peak temperature, and radiative loss fraction were found to be independent of flow rate except at very low flow rates. Radiative heat loss was dominated by the combustion products downstream of the flame and was found to scale with flame surface area, not volume. For large transient flames the heat release rate also scaled with surface area and thus the radiative loss fraction was largely independent of flow rate. Peak temperatures at extinction onset were about I 100 K, which is significantly lower than for kinetic extinction. An important observation of this work is that while radiative heat losses can drive transient extinction, this is not only because radiative losses are increasing with time but also because the heat release rate is falling off as the flame expands away from the burner and the reactant supply to the flame decreases. (c) 2007 The Combustion Institute. Published by Elsevier Inc. All rights reserved. C1 Washington Univ, Dept Mech & Aerosp Engn, St Louis, MO 63130 USA. Univ Hawaii Manoa, Dept Engn Mech, Honolulu, HI 96822 USA. Univ Maryland, Dept Fire Protect Engn, College Pk, MD 20742 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Axelbaum, RL (reprint author), Washington Univ, Dept Mech & Aerosp Engn, St Louis, MO 63130 USA. EM rla@wustl.edu OI Sunderland, Peter/0000-0002-8262-7100 NR 31 TC 11 Z9 11 U1 0 U2 7 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 2007 VL 151 IS 4 BP 665 EP 675 DI 10.1016/j.combustflame.2007.08.009 PG 11 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 238WN UT WOS:000251479000009 ER PT J AU Holzmann, GJ AF Holzmann, Gerard J. TI Conquering complexity SO COMPUTER LA English DT Article C1 CALTECH, NASA, Jet Propuls Lab, Labor Reliable Software, Pasadena, CA 91125 USA. RP Holzmann, GJ (reprint author), CALTECH, NASA, Jet Propuls Lab, Labor Reliable Software, Pasadena, CA 91125 USA. EM gholzmann@acm.org NR 0 TC 5 Z9 5 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0018-9162 J9 COMPUTER JI Computer PD DEC PY 2007 VL 40 IS 12 BP 111 EP 113 DI 10.1109/MC.2007.419 PG 3 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA 238DU UT WOS:000251428300016 ER PT J AU Cates, GR Mollaghasemi, M AF Cates, Grant R. Mollaghasemi, Mansooreh TI The project assessment by simulation technique SO EMJ-ENGINEERING MANAGEMENT JOURNAL LA English DT Article DE project management; discrete event simulation; Monte Carlo; stochastic; uncertainty; risk AB Project uncertainty is present in many places including the estimates for activity durations, in the Occurrence of unplanned or unforeseen events, and in the availability of critical resources. The impact call be project completion delays, increased costs, and decreased stakeholder benefit. The Project Assessment by Simulation Technique (PAST) enhances stakeholder visibility of project uncertainty, i.e., risk to project completion performance. In certain situations, this enhanced visibility may lead to improved project risk management and improved project completion performance. An engineering manager Call use this article to gain insights into the PAST methodology, its use oil a large complex project, and its potential benefits to project management. C1 [Mollaghasemi, Mansooreh] Univ Cent Florida, Dept Ind Engn & Management Syst, Orlando, FL 32816 USA. [Cates, Grant R.] NASA, Greenbelt, MD 20771 USA. RP Cates, GR (reprint author), 9674 Loblolly Pine Circle, Orlando, FL 32827 USA. EM grant.r.cates@saic.com NR 14 TC 4 Z9 4 U1 2 U2 5 PU AMER SOC ENGINEERING MANAGEMENT PI ROLLA PA PO BOX 820, ROLLA, MO 65402 USA SN 1042-9247 J9 EMJ-ENG MANAG J JI EMJ-Eng. Manag. J. PD DEC PY 2007 VL 19 IS 4 BP 3 EP 10 PG 8 WC Engineering, Industrial; Management SC Engineering; Business & Economics GA 340RS UT WOS:000258663300002 ER PT J AU Harper, GJ Steininger, MK Tucker, CJ Juhn, D Hawkins, F AF Harper, Grady J. Steininger, Marc K. Tucker, Compton J. Juhn, Daniel Hawkins, Frank TI Fifty years of deforestation and forest fragmentation in Madagascar SO ENVIRONMENTAL CONSERVATION LA English DT Article DE deforestation; forest; fragmentation; Madagascar; remote sensing ID TROPICAL DEFORESTATION; HABITAT FRAGMENTATION; HIGHLAND MADAGASCAR; SATELLITE DATA; AMAZON; EXTINCTION; DIVERSITY AB Tropical deforestation is a key contributor to species extinction and climate change, yet the extent of tropical forests and their rate of destruction and degradation through fragmentation remain poorly known. Madagascar's forests are among the most biologically rich and unique in the world but, in spite of longstanding concern about their destruction, past estimates of forest cover and deforestation have varied widely. Analysis of aerial photographs (c. 1953) and Landsat images (c. 1973, c. 1990 and c. 2000) indicates that forest cover decreased by almost 40% from the 1950s to c. 2000, with a reduction in 'core forest' > 1 km from a non-forest edge of almost 80%. This forest destruction and degradation threaten thousands of species with extinction. Country-wide coverage of high-resolution validated forest cover and deforestation data enables the precise monitoring of trends in habitat extent and fragmentation critical for assessment of species' conservation status. C1 [Harper, Grady J.; Steininger, Marc K.; Juhn, Daniel; Hawkins, Frank] Conservat Int, Arlington, VA 22202 USA. [Tucker, Compton J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Hawkins, Frank] Conservat Int, Antananarivo 101, Madagascar. RP Harper, GJ (reprint author), Conservat Int, 2011 Crystal Dr,Suite 500, Arlington, VA 22202 USA. EM gharper@conservation.org NR 40 TC 197 Z9 205 U1 26 U2 163 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0376-8929 J9 ENVIRON CONSERV JI Environ. Conserv. PD DEC PY 2007 VL 34 IS 4 BP 325 EP 333 DI 10.1017/S0376892907004262 PG 9 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 294AO UT WOS:000255376700007 ER PT J AU Grace, MA Driggers, WB Forrester, J Hopkins, N AF Grace, Mark A. Driggers, William B., III Forrester, Jack Hopkins, Nicholas TI Landing sling use increases data accuracy and sampling opportunities for large marine fishes captured during fishery-independent longline surveys SO FISHERIES RESEARCH LA English DT Article DE landing sling; large marine fishes; longline surveys AB For fisheries research the lengths and weights of fishes are important data elements used to characterize biological dynamics; however, in order to collect accurate lengths and weights there can be stress and mortality issues due to handling methods. In particular, during coastal and oceanic longline projects, collecting accurate biological data from large animals is often problematic due to associated landing and handling difficulties. To improve the accuracy of biological data collected from large specimens and decrease survey-induced stress and mortalities during longline surveys, a portable landing sling was designed for use with shipboard hydraulic cranes. The landing sling enables researchers to improve biological data quality through increased opportunities to collect accurate lengths and weights, take detailed photographs, and conduct non-invasive biological sampling with minimal physical damage to large fishes captured. Thus, using a landing sling allows researchers to collect essential biological data while being responsibly conservative. (C) 2007 Published by Elsevier B.V. C1 [Grace, Mark A.; Driggers, William B., III; Forrester, Jack; Hopkins, Nicholas] Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Mississippi Labs, Pascagoula, MS 39568 USA. RP Grace, MA (reprint author), Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Mississippi Labs, PO Drawer 1207, Pascagoula, MS 39568 USA. EM Mark.A.Grace@noaa.gov; William.Driggers@noaa.gov; Jack.Forrester@noaa.gov; Nick.Hopkins@noaa.gov NR 1 TC 2 Z9 2 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD DEC PY 2007 VL 88 IS 1-3 BP 146 EP 149 DI 10.1016/j.fishres.2007.07.016 PG 4 WC Fisheries SC Fisheries GA 242XT UT WOS:000251760200017 ER PT J AU Gaidos, E Dubuc, T Dunford, M McAndrew, P Padilla-Gamino, J Studer, B Weersing, K Stanley, S AF Gaidos, E. Dubuc, T. Dunford, M. McAndrew, P. Padilla-Gamino, J. Studer, B. Weersing, K. Stanley, S. TI The Precambrian emergence of animal life: a geobiological perspective SO GEOBIOLOGY LA English DT Review ID BILLION YEARS AGO; NEOPROTEROZOIC DOUSHANTUO FORMATION; PROTEROZOIC OCEAN CHEMISTRY; CARBON-ISOTOPE EXCURSIONS; VASE-SHAPED MICROFOSSILS; BANDED IRON-FORMATIONS; TRACE-FOSSIL RECORD; TRUE POLAR WANDER; PB ZIRCON AGE; CAMBRIAN EXPLOSION AB The earliest record of animals (Metazoa) consists of trace and body fossils restricted to the last 35 Myr of the Precambrian. It has been proposed that animals arose much earlier and underwent significant evolution as a cryptic fauna; however, the need for any unrecorded prelude of significant duration has been disputed. In this context, we consider recent published research on the nature and chronology of the earliest fossil record of metazoans and on the molecular-based analysis that yielded older dates for the appearance of major animal groups. We review recent work on the climatic, geochemical, and ecological events that preceded animal fossils and consider their portent for metazoan evolution. We also discuss inferences about the physiology and gene content of the last common ancestor of animals and their closest unicellular relatives. We propose that the recorded Precambrian evolution of animals includes three intervals of advancement that begin with sponge-grade organisms, and that any preceding cryptic fauna would be no more complex than sponges. The molecular data do not require that more complex animals appeared well before the recognized fossil record; nor, however, do they rule the possibility out, particularly if the interval of simpler metazoan ancestors lasted no more than about 100 or 200 Myr. The geological record of abrupt changes in climate, biogeochemistry, and phytoplankton diversity can be taken to be the result of changes in the carbon cycle triggered by the appearance and diversification of metazoans in an organic carbon-rich ocean, but as yet no compelling evidence exists for this interpretation. By the end of this cryptic period, animals would already have possessed sophisticated systems of cell-cell signalling, adhesion, apoptosis, and segregated germ cells, possibly with a rudimentary body plan based on anterior-posterior organization. The controls on the timing and tempo of the earliest steps in metazoan evolution are unknown, but it seems likely that oxygen was a key factor in later diversification and increase in body size. We consider several recent scenarios describing how oxygen increased near the end of the Precambrian and propose that grazing and filter-feeding animals depleted a marine reservoir of suspended organic matter, releasing a microbial 'clamp' on atmospheric oxygen. C1 Univ Hawaii Manoa, Dept Geol & Geophys, Honolulu, HI 96822 USA. Univ Hawaii Manoa, Dept Zool, Honolulu, HI 96822 USA. Univ Hawaii Manoa, Dept Oceanog, Honolulu, HI 96822 USA. NASA, Astrobiol Inst, Washington, DC 20006 USA. RP Gaidos, E (reprint author), Univ Hawaii Manoa, Dept Geol & Geophys, Honolulu, HI 96822 USA. EM gaidos@hawaii.edu NR 287 TC 24 Z9 25 U1 3 U2 30 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1472-4677 EI 1472-4669 J9 GEOBIOLOGY JI Geobiology PD DEC PY 2007 VL 5 IS 4 BP 351 EP 373 DI 10.1111/j.1472-4669.2007.00125.x PG 23 WC Biology; Environmental Sciences; Geosciences, Multidisciplinary SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Geology GA 232NO UT WOS:000251026600004 ER PT J AU Yu, JY Park, Y Mielke, RE Coleman, ML AF Yu, Jae-Young Park, Youngyun Mielke, Randall E. Coleman, Max L. TI Sulfur and oxygen isotopic compositions of the dissolved sulphate in the meteoric water in Chuncheon, Korea SO GEOSCIENCES JOURNAL LA English DT Article DE sulfur and oxygen isotope; meteoric water; pollutant sulfur sources; acid forming processes ID DIOXIDE; TRANSPORT; OXIDATION; SITES; MODEL; ASIA AB The meteoric water deposited in the Chuncheon area was collected from July 2002 to May 2004 and its chemical and isotopic compositions were analyzed to examine if the isotopic data can help trace the sources of the sulfur pollutant and understand the details of acid formation processes in the air. The chemical compositions of the meteoric water indicate that the sulfate mostly comes from anthropogenic sources. The sulfur isotopic compositions of the dissolved sulfate in the meteoric water (delta S-34(S04)) vary from 2.6 to 7.5 parts per thousand with little seasonal differences, which are significantly different from those of the sulfur in the coal being locally consumed (-4.5 to -0.7 parts per thousand). This difference indicates that the local coal consumption gives insignificant contribution to the pollutant sulfur in the acid deposition of the area. The relationship between delta S-34(S04) and the concentration of sulfate suggests that the sources of pollutant sulfur are variable and inhomogeneous. The oxygen isotopic compositions of the dissolved sulfate in the meteoric water delta O-18(S04)) range from 9.0 to 17.2 parts per thousand, which are generally lower in winter than in spring. Comparison between the measured and calculated values of delta O-18(S04) suggests that the oxygen isotopic exchange between sulfite and water occurs before its oxidation to sulfate. The extent of isotopic exchange seems to be not controlled by equilibrium but by kinetic fractionation. The poor correlation between delta O-18(S04) and the oxygen isotopic composition of the meteoric water confirms the disequilibrium nature of the isotopic exchange. C1 [Yu, Jae-Young; Park, Youngyun] Kangwon Natl Univ, Dept Geol, Chunchon 200701, Kangwon Do, South Korea. [Mielke, Randall E.; Coleman, Max L.] Ctr Life Detect, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Yu, JY (reprint author), Kangwon Natl Univ, Dept Geol, Chunchon 200701, Kangwon Do, South Korea. EM jyu@kangwon.ac.kr RI Coleman, Max/A-1303-2007 OI Coleman, Max/0000-0002-5514-1826 NR 32 TC 9 Z9 9 U1 2 U2 5 PU ASSOC KOREAN GEOSCIENCE SOC PI SEOUL PA C/O THE KOREA SCIENCE & TECHNOLOGY CENTER, RM 813, 635-4 YEOKSAM-DONG, GANGNAM-GU, SEOUL, 135-708, SOUTH KOREA SN 1226-4806 J9 GEOSCI J JI Geosci. J. PD DEC PY 2007 VL 11 IS 4 BP 357 EP 367 DI 10.1007/BF02857051 PG 11 WC Geosciences, Multidisciplinary SC Geology GA 247GE UT WOS:000252065200007 ER PT J AU Bolton, ML Bass, EJ Comstock, JR AF Bolton, Matthew L. Bass, Ellen J. Comstock, James Raymond, Jr. TI Spatial awareness in synthetic vision systems: Using spatial and temporal judgments to evaluate texture and field of view SO HUMAN FACTORS LA English DT Article ID SITUATION AWARENESS; ELEVATION; DISPLAY AB Objective: This work introduced judgment-based measures of spatial awareness and used them to evaluate terrain textures and fields of view (FOVs) in synthetic vision system (SVS) displays. Background: SVSs are cockpit technologies that depict computer-generated views of terrain surrounding an aircraft. In the assessment of textures and FOVs for SVSs, no studies have directly measured the three levels of spatial awareness with respect to terrain: identification of terrain, its relative spatial location, and its relative temporal location. Methods: Eighteen pilots made four judgments (relative azimuth angle, distance, height, and abeam time) regarding the location of terrain points displayed in 112 noninteractive 5-s simulations of an SVS head-down display. There were two between-subject variables (texture order and FOV order) and five within-subject variables (texture, FOV, and the terrain point's relative azimuth angle, distance, and height). Results: Texture produced significant main and interaction effects for the magnitude of error in the relative angle, distance, height, and abeam time judgments. FOV interaction effects were significant for the directional magnitude of error in the relative distance, height, and abeam time judgments. Conclusion: Spatial awareness was best facilitated by the elevation fishnet (EF), photo fishnet (PF), and photo elevation fishnet (PEF) textures. Application: This study supports the recommendation that the EF, PF, and PEF textures be further evaluated in future SVS experiments. Additionally, the judgment-based spatial awareness measures used in this experiment could be used to evaluate other display parameters and depth cues in SVSs. C1 Univ Virginia, Dept Syst & Informat Engn, Charlottesville, VA 22904 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Bass, EJ (reprint author), Univ Virginia, Dept Syst & Informat Engn, 151 Engn Way, Charlottesville, VA 22904 USA. EM ejb4n@virginia.edu RI Bolton, Matthew/G-5199-2012; Bolton, Matthew/A-6390-2016 NR 34 TC 13 Z9 14 U1 0 U2 2 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0018-7208 J9 HUM FACTORS JI Hum. Factors PD DEC PY 2007 VL 49 IS 6 BP 961 EP 974 DI 10.1518/001872007X249848 PG 14 WC Behavioral Sciences; Engineering, Industrial; Ergonomics; Psychology, Applied; Psychology SC Behavioral Sciences; Engineering; Psychology GA 232UC UT WOS:000251044200001 PM 18074697 ER PT J AU Williams, JA Bridgeman, B Woods, T Welch, R AF Williams, Jason A. Bridgeman, Bruce Woods, Tadg Welch, Robert TI Global VOR gain adaptation during near fixation to foveal targets SO HUMAN MOVEMENT SCIENCE LA English DT Article DE vestibulo-ocular reflex; adaptive plasticity; vergence; adaptation; motor processes ID APPARENT CONCOMITANT MOTION; CONTEXT-SPECIFIC ADAPTATION; VESTIBULO-OCULAR REFLEX; COMPENSATORY EYE-MOVEMENTS; HUMAN GAZE STABILIZATION; DUAL ADAPTATION; PLASTICITY; MAGNIFICATION; DIRECTION; VERGENCE AB Long-term rotational vestibulo-ocular (VOR) adaptation occurs during systematic dysmetria, between visual and vestibular afferents, adjusting eye-rotation angular velocity to re-establish retinal stability of the visual field. Due to translational motion of the eyes during head rotation, VOR gain is higher when fixating near objects. The current study measures VOR in humans before and after 6 min of exposure to a foveal near-target during sinusoidal whole-body rotation at 0.45 Hz. All of six participants showed post-exposure increases in open-loop VOR gain after fixating near targets, demonstrating a mean modulation increase of open-loop VOR gain from 0.86 before adaptation to 1.2 after adaptation. We discuss a number of theoretical and applied implications. (c) 2007 Elsevier B.V. All rights reserved. C1 [Williams, Jason A.] Gonzaga Univ, Dept Psychol, Spokane, WA 99258 USA. [Bridgeman, Bruce] Univ Calif Santa Cruz, Dept Psychol, Santa Cruz, CA 95064 USA. [Bridgeman, Bruce] Univ Calif Santa Cruz, Dept Psychobiol, Santa Cruz, CA 95064 USA. [Woods, Tadg] Gonzaga Univ, Dept Math, Spokane, WA USA. [Welch, Robert] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Williams, JA (reprint author), Gonzaga Univ, Dept Psychol, 501 E Boone Ave,AD54, Spokane, WA 99258 USA. EM williamsj@gonzaga.edu NR 31 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9457 J9 HUM MOVEMENT SCI JI Hum. Mov. Sci. PD DEC PY 2007 VL 26 IS 6 BP 787 EP 795 DI 10.1016/j.humov.2007.06.002 PG 9 WC Neurosciences; Psychology; Psychology, Experimental; Sport Sciences SC Neurosciences & Neurology; Psychology; Sport Sciences GA 243HT UT WOS:000251788100001 PM 17870197 ER PT J AU Dobrovolskis, AR AF Dobrovolskis, Anthony R. TI Spin states and climates of eccentric exoplanets SO ICARUS LA English DT Article DE celestial mechanics; extrasolar planets; resonances; spin-orbit; rotational dynamics; tides; solid body ID ATMOSPHERIC TIDES; NONSYNCHRONOUS ROTATION; PLANET MERCURY; SOLAR SYSTEM; EUROPA; SATELLITES; EVOLUTION; VENUS; RESONANCES; NEREID AB The known extrasolar planets exhibit a wide range of orbital eccentricities e. This has a profound influence on their rotations and climates. Because of tides in their interiors, mostly solid exoplanets are expected eventually to despin to a state of spin-orbit resonance, where the orbital period is some integer or half-integer times the rotation period. The most important of these resonances is the synchronous state, where the planet's spin period exactly equals its orbital period (like Earth's Moon, and indeed most of the regular satellites in the Solar System). Such planets seem doomed to roast on one side and freeze on the other. However, synchronous planets rock back and forth by an angle of similar to 2 Arcsin e with respect to the sub-stellar point. For e = 0.055 (as for the Moon), this optical libration amounts to only similar to 6 degrees; but for a synchronous planet with e = 0.50, for example, it would rise to similar to 59 degrees. This greatly expands the temperate "twilight zone" near the terminator and considerably improves the planet's prospects for habitability. For e greater than or similar to 0.72389, the optical libration exceeds 90 degrees; for such planets, the sector of permanent night vanishes, while the sunniest region splits in two. Furthermore, the synchronous state is not the only possible spin resonance. For example, Mercury (with e approximate to 0.206) has an orbital period exactly 1.5 times its rotation period. A terrestrial exoplanet with e = 0.40, say, is liable to have an orbital period of 2.0, 2.5, or 3.0 times its spin period. The corresponding insolation patterns are generally complicated, and all different from the synchronous state. Yet these non-synchronous resonances also protect certain longitudes from the worst extremes of temperature and solar radiation, and improve the planet's habitability, compared to non-resonant rotation. These results also have implications for the direct delectability of extrasolar planets, and the interpretation of their thermal emissions. (c) 2007 Elsevier Inc. All rights reserved. C1 [Dobrovolskis, Anthony R.] Univ Calif Santa Cruz, NASA, Ames Res Ctr, Lick Observ, Moffett Field, CA 94035 USA. RP Dobrovolskis, AR (reprint author), Univ Calif Santa Cruz, NASA, Ames Res Ctr, Lick Observ, Moffett Field, CA 94035 USA. EM dobro@cosmic.arc.nasa.gov NR 39 TC 20 Z9 20 U1 0 U2 4 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 EI 1090-2643 J9 ICARUS JI Icarus PD DEC 1 PY 2007 VL 192 IS 1 BP 1 EP 23 DI 10.1016/j.icarus.2007.07.005 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 241JL UT WOS:000251652600001 ER PT J AU Radebaugh, J Lorenz, RD Kirk, RL Lunine, JI Stofan, ER Lopes, RMC Wall, SD AF Radebaugh, Jani Lorenz, Ralph D. Kirk, Randolph L. Lunine, Jonathan I. Stofan, Ellen R. Lopes, Rosaly M. C. Wall, Stephen D. CA Cassini Radar Team TI Mountains on Titan observed by Cassini Radar SO ICARUS LA English DT Article DE Titan; Satellites; surfaces; Saturn; satellites; Tectonics ID SURFACE; ICE; METHANE; ORIGIN; EJECTA; MAPPER; MARS AB The Cassini Titan Radar mapper has observed elevated blocks and ridge-forming block chains on Saturn's moon Titan demonstrating high topography we term "mountains." Summit flanks measured from the T3 (February 2005) and T8 (October 2005) flybys have a mean maximum slope of 37 degrees and total elevations up to 1930 in as derived from a shape-from-shading model corrected for the probable effects of image resolution. Mountain peak morphologies and surrounding, diffuse blankets give evidence that erosion has acted upon these features, perhaps in the form of fluvial runoff. Possible formation mechanisms for these mountains include crustal compressional tectonism and upthrusting of blocks, extensional tectonism and formation of horst-and-graben, deposition as blocks of impact ejecta, or dissection and erosion of a preexisting layer of material. All above processes may be at work, given the diversity of geology evident across Titan's surface. Comparisons of mountain and blanket volumes and erosion rate estimates for Titan provide a typical mountain age as young as 20-100 million years. (c) 2007 Elsevier Inc. All rights reserved. C1 [Radebaugh, Jani] Brigham Young Univ, Dept Geol Sci, Provo, UT 84602 USA. [Lorenz, Ralph D.] Johns Hopkins Univ, Appl Phys Lab, Dept Space, Planetary Explorat Grp, Laurel, MD 20723 USA. [Kirk, Randolph L.] US Geol Survey, Div Astrogeol, Flagstaff, AZ 86001 USA. [Radebaugh, Jani; Lorenz, Ralph D.; Lunine, Jonathan I.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. [Lunine, Jonathan I.] INAF, IFSI, I-00133 Rome, Italy. [Stofan, Ellen R.] Proxemy Res, Bowie, MD 20715 USA. [Lopes, Rosaly M. C.; Wall, Stephen D.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Radebaugh, J (reprint author), Brigham Young Univ, Dept Geol Sci, Provo, UT 84602 USA. EM jani.radebaugh@byu.edu RI Lorenz, Ralph/B-8759-2016; Lopes, Rosaly/D-1608-2016 OI Lorenz, Ralph/0000-0001-8528-4644; Lopes, Rosaly/0000-0002-7928-3167 NR 52 TC 78 Z9 79 U1 0 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC 1 PY 2007 VL 192 IS 1 BP 77 EP 91 DI 10.1016/j.icarus.2007.06.020 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 241JL UT WOS:000251652600005 ER PT J AU Bland, MT Beyer, RA Showman, AP AF Bland, Michael T. Beyer, Ross A. Showman, Adam P. TI Unstable extension of Enceladus' lithosphere SO ICARUS LA English DT Article DE Enceladus; Satellites; surfaces; Tectonics ID GANYMEDES GROOVED TERRAIN; STRAIN LOCALIZATION; HEAT-FLUX; MODEL; ICE; INSTABILITY; TOPOGRAPHY; EVOLUTION; ORIGIN; CREEP AB Regions near Enceladus' equator, Sarandib and Diyar Planitia, contain extensive sets of parallel ridges and troughs that may be diagnostic of the region's formation conditions. We present photoclinometry profiles across these ridges and troughs, which indicate that they are periodic, low-slope features with dominant wavelengths of 3 to 4 km and amplitudes between 100 and 400 m. The morphology of these terrains is consistent with formation via unstable extension of the lithosphere. Our numerical modeling demonstrates that unstable extension can generate largescale topography under Enceladus-like conditions. Comparison of our photoclinometry profiles with the dominant wavelengths produced by our numerical model permits estimation of the background heat flow at the time the Sarandib-Diyar province formed. We estimate heat flows of I 10 to 220 mWm(-2), suggesting that resurfacing of the planitiae was accompanied by strong, localized heating. The extension necessary to produce the ridges and troughs may have been caused by now-inactive diapirs, internal phase changes, or other mechanisms. Our heat flux estimates imply elastic thickness at the time of resurfacing of 0.4 to 1.4 km, which are sufficient to have allowed satellite reorientation if the province was underlain by a low-density region. It is therefore plausible that Enceladus has experienced multiple heating events, each leading to localized resurfacing and global reorientation. (c) 2007 Elsevier Inc. All rights reserved. C1 [Bland, Michael T.; Showman, Adam P.] Univ Arizona, Lunar & Planetary Lab, Dept Planetary Sci, Tucson, AZ 85721 USA. [Beyer, Ross A.] Carl Sagan Ctr, SETI Inst, Mountain View, CA 94035 USA. [Beyer, Ross A.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Bland, MT (reprint author), Univ Arizona, Lunar & Planetary Lab, Dept Planetary Sci, Tucson, AZ 85721 USA. EM mbland@lpl.arizona.edu OI Beyer, Ross/0000-0003-4503-3335 NR 52 TC 23 Z9 23 U1 1 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC 1 PY 2007 VL 192 IS 1 BP 92 EP 105 DI 10.1016/j.icarus.2007.06.011 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 241JL UT WOS:000251652600006 ER PT J AU Schenk, PM Zahnle, K AF Schenk, Paul M. Zahnle, Kevin TI On the negligible surface age of Triton SO ICARUS LA English DT Article DE Triton; cratering; Neptune; satellites; comets ID JUPITER-FAMILY COMETS; GEYSER-LIKE PLUMES; ECLIPTIC COMETS; SIZE DISTRIBUTION; CRATERING RATES; KUIPER-BELT; EUROPA; DISCOVERY; SYSTEM; CONSTRAINTS AB New mapping reveals 100 probable impact craters on Triton wider than 5 kin diameter. All of the probable craters are within 90 of the apex of Triton's orbital motion (i.e., all are on the leading hemisphere) and have a cosine density distribution with respect to the apex. This spatial distribution is difficult to reconcile with a heliocentric (Sun-orbiting) source of impactors, be it ecliptic comets, the Kuiper Belt, the scattered disk, or tidally-disrupted temporary satellites in the style of Shoemaker-Levy 9, but it is consistent with head-on collisions, as would be produced if a prograde population of planetocentric (Neptune-orbiting) debris were swept up by retrograde Triton. Plausible sources include ejecta from impact on or disruption of inner/outer moons of Neptune. If Triton's small craters are mostly of planetocentric origin, Triton offers no evidence for or against the existence of small comets in the Kuiper Belt, and New Horizons observations of Pluto must fill this role. The possibility that the distribution of impact craters is an artifact caused by difficulty in identifying impact craters on the cantaloupe terrain is considered and rejected. The possibility that capricious resurfacing has mimicked the effect of head-on collisions is considered and shown to be unlikely given current geologic constraints, and is no more probable than planetocentrogenesis. The estimated cratering rate on Triton by ecliptic comets is used to put an upper limit of similar to 50 Myr on the age of the more heavily cratered terrains, and of similar to 6 Myr for the Neptune-facing cantaloupe terrain. If the vast majority of cratering is by planetocentric debris, as we propose, then the surface everywhere is probably less than 10 Myr old. Although the uncertainty in these cratering ages is at least a factor ten, it seems likely that Triton's is among the youngest surfaces in the Solar System, a candidate ocean moon, and an important target for future exploration. (c) 2007 Elsevier Inc. All rights reserved. C1 [Schenk, Paul M.] Lunar & Planetary Inst, Houston, TX 77058 USA. [Zahnle, Kevin] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Schenk, PM (reprint author), Lunar & Planetary Inst, 3600 Bay Area Blvd, Houston, TX 77058 USA. EM schenk@lpi.usra.edu NR 49 TC 30 Z9 30 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC 1 PY 2007 VL 192 IS 1 BP 135 EP 149 DI 10.1016/j.icarus.2007.07.004 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 241JL UT WOS:000251652600009 ER PT J AU Anderson, GT Tunstel, EW Wilson, EW AF Anderson, Gary T. Tunstel, Edward W. Wilson, Edmond W. TI Robot system to search for signs of life on Mars SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article ID MARTIAN METEORITE; SURFACE; ENVIRONMENT; ROCKS; SOIL AB This describes a robot system that can be used to look for the tell-tale signs of life on Mars. Currently, NASA has satellites in orbit that can identify broad regions to explore in its search for life. NASA also has instruments that can examine samples of Martian soil to see if they contain any indications of biological activity. This leaves the problem of deciding specifically where to look for suitable samples in the large area around a landing site. This also describes a robot system that can rapidly search thousands of square meters around the landing position to find sources of biogenic gas samples that may harbor important clues in the search for extra-terrestrial life. C1 [Tunstel, Edward W.] Jet Propuls Lab, Adv Robot Controls Lab, Pasadena, CA 91109 USA. [Wilson, Edmond W.] Harding Univ, Dept Chem, Searcy, AR USA. RP Anderson, GT (reprint author), Univ Arkansas, Dept Appl Sci, Little Rock, AR 72204 USA. NR 33 TC 7 Z9 7 U1 2 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0885-8985 EI 1557-959X J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD DEC PY 2007 VL 22 IS 12 BP 23 EP 30 DI 10.1109/MAES.2007.4408598 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 267JU UT WOS:000253506100004 ER PT J AU Gawronski, W AF Gawronski, Wodek TI Servo-performance parameters of the NASA deep space network antennas SO IEEE ANTENNAS AND PROPAGATION MAGAZINE LA English DT Article DE antenna measurements; antenna mechanical factors; antenna transient analysis; reflector antennas; reflector antenna mechanical factors; control systems; servo motors; servo systems; antenna pointing AB The performance of an antenna control system is evaluated using performance parameters such as settling time, bandwidth, steady-state error in rate offsets, and antenna root-mean-square servo error while tracking in wind gusts. The performance parameters are measured in the field, or obtained through analysis and simulations. Limited access time to antennas, incomplete test equipment, limited test/analysis time, and partial models do not allow determination of all the parameters. However, field practice and analytical results indicate correlations among them; hence, even incomplete knowledge of the performance parameters would allow for estimation of the missing parameters. This paper investigates the relationships of the antenna performance parameters as a function of controller gains. It also establishes the interrelationships among the parameters. It does this for an idealized (or rigid) antenna, and extends the relationships to the NASA Deep Space Network antennas (flexible structures with dish sizes of 34 or 70 meters). The results obtained should simplify antenna testing, and allow for better performance evaluation from limited data. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gawronski, W (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM wodek.k.gawronski@jpl.nasa.gov NR 12 TC 2 Z9 3 U1 1 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1045-9243 EI 1558-4143 J9 IEEE ANTENN PROPAG M JI IEEE Antennas Propag. Mag. PD DEC PY 2007 VL 49 IS 6 BP 40 EP 46 DI 10.1109/MAP.2007.4455845 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 256IS UT WOS:000252722500005 ER PT J AU Schlecht, E Gill, J Dengler, R Lin, R Tsang, R Mehdi, I AF Schlecht, Erich Gill, John Dengler, Robert Lin, Robert Tsang, Ray Mehdi, Imran TI Unique 520-590 GHz biased subharmonically pumped Schottky mixer SO IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS LA English DT Article DE Schottky diode mixers; submillimeter wave diodes; submillimeter wave mixers ID MILLIMETER-WAVE MIXERS; DIODES; NOISE; GAAS; MICROWAVE AB We report on the design and performance of a novel broadband, biased, subharmonic 520-590 GHz fix-tuned frequency mixer that utilizes planar Schottky diodes. The suspended stripline circuit is fabricated on a GaAs membrane mounted in a split waveguide block. The chip is supported by thick beam leads that are also used to provide precise radio frequency (RF) grounding, RF coupling and dc/intermediate frequency connections. At room temperature, the mixer has a measured double sideband noise temperature of 3000 to 4000 K across the design band. C1 [Schlecht, Erich; Gill, John; Dengler, Robert; Lin, Robert; Tsang, Ray; Mehdi, Imran] CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Schlecht, E (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. EM erich.schlecht@jpl.nasa.gov NR 19 TC 18 Z9 19 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1531-1309 J9 IEEE MICROW WIREL CO JI IEEE Microw. Wirel. Compon. Lett. PD DEC PY 2007 VL 17 IS 12 BP 879 EP 881 DI 10.1109/LMWC.2007.910506 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 242RN UT WOS:000251743400023 ER PT J AU Howe, AS AF Howe, A. Scott TI Self-assembling modular robotic structures - Standard units with swappable payloads SO IEEE ROBOTICS & AUTOMATION MAGAZINE LA English DT Article DE modular robotics; self-reconfiguring structures; space construction C1 NASA, Jet Propuls Lab, Mission Syst Concepts Sect, Explorat Syst Concepts Grp, Pasadena, CA 91109 USA. RP Howe, AS (reprint author), NASA, Jet Propuls Lab, Mission Syst Concepts Sect, Explorat Syst Concepts Grp, 4800 Oak Grove Dr,M-S 301-165, Pasadena, CA 91109 USA. EM a.scott.howe@jpl.nasa.gov NR 22 TC 1 Z9 2 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1070-9932 J9 IEEE ROBOT AUTOM MAG JI IEEE Robot. Autom. Mag. PD DEC PY 2007 VL 14 IS 4 BP 26 EP 33 DI 10.1109/M-RA.2007.908986 PG 8 WC Automation & Control Systems; Robotics SC Automation & Control Systems; Robotics GA 245YH UT WOS:000251974200007 ER PT J AU Perrins, E Schober, R Rice, M Simon, MK AF Perrins, Erik Schober, Robert Rice, Michael Simon, Marvin K. TI Multiple-bit differential detection of shaped-offset QPSK SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article DE continuous phase modulation (CPM); differential shaped offset quadrature phase shift keying (DSOQPSK); multiple-bit differential detection (MBDD); performance analysis ID SOQPSK; DPSK; MPSK AB We consider multiple-bit differential detection (MBDD) of differentially encoded shaped-offset quadrature phase-shift keying (SOQPSK), a highly bandwidth-efficient and popular constant-envelope modulation. We propose two MBDD schemes that are based on a recent continuous phase modulation interpretation of SOQPSK. We show that the performance of these MBDD schemes approaches that of coherent detection (CD) as the multiple-bit observation window N increases. The first scheme uses a detection window that spans the full N-bit observation window (F-MBDD), and is shown to require very large values of N to approach the performance of CD. This presents a practical problem since the complexity of MBDD grows exponentially with N. The second scheme is an improved version (I-MBDD) with a detection window that is shortened to N - 2 bit intervals. Although the complexity of I-MBDD also increases exponentially with N, it represents a significant improvement since only modest values of N are needed for high performance. These performance characteristics are identified via a detailed performance analysis, which provides asymptotic formulas for the bit error probability that are confirmed with computer simulations. The analysis is also used to find the symmetric frequency pulse shapes with the best and worst error performance. Finally, we develop a simplified and practical decision feedback differential detection algorithm that achieves near-optimal performance with complexity that grows only linearly with N. C1 [Perrins, Erik] Univ Kansas, Dept Elect Engn & Comp Sci, Lawrence, KS 66045 USA. [Schober, Robert] Univ British Columbia, Dept Elect & Comp Engn, Vancouver, BC V6T 1Z4, Canada. [Rice, Michael] Brigham Young Univ, Dept Elect & Comp Engn, Provo, UT 84602 USA. [Simon, Marvin K.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Perrins, E (reprint author), Univ Kansas, Dept Elect Engn & Comp Sci, Lawrence, KS 66045 USA. EM esp@ieee.org; rschober@ece.ubc.ca; mdr@ee.byu.edu NR 22 TC 7 Z9 8 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0090-6778 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD DEC PY 2007 VL 55 IS 12 BP 2328 EP 2340 DI 10.1109/TCOMM.2007.910972 PG 13 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 242SG UT WOS:000251745400015 ER PT J AU Clausi, DA Aksoy, S Tilton, AC AF Clausi, David A. Aksoy, Selim Tilton, Ames C. TI Foreword to the special issue on pattern recognition in remote sensing SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Editorial Material C1 Univ Waterloo, Dept Syst Design Engn, Waterloo, ON N2L 3G1, Canada. Bilkent Univ, Dept Comp Engn, TR-06800 Ankara, Turkey. NASA, Goddard Space Flight Ctr, Computat & Informat Sci & Technol Off, Greenbelt, MD 20771 USA. RP Clausi, DA (reprint author), Univ Waterloo, Dept Syst Design Engn, Waterloo, ON N2L 3G1, Canada. RI Aksoy, Selim/C-3365-2008 OI Aksoy, Selim/0000-0003-4185-0565 NR 0 TC 4 Z9 4 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD DEC PY 2007 VL 45 IS 12 BP 3855 EP 3856 DI 10.1109/TGRS.2007.909915 PN 1 PG 2 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 236YL UT WOS:000251339400001 ER PT J AU Deal, WR Mei, XB Radisic, V Lange, MD Yoshida, W Liu, PH Uyeda, J Barsky, ME Fung, A Gaier, T Lai, R AF Deal, William R. Mei, X. B. Radisic, Vesna Lange, Michael D. Yoshida, Wayne Liu, Po-hsin Uyeda, Jansen Barsky, Michael E. Fung, Andy Gaier, Todd Lai, Richard TI Development of sub-millimeter-wave power amplifiers SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article; Proceedings Paper CT IEEE Annual Microwave-Theory-and-Techniques-Society International Microwave Symposium CY JUN 03-08, 2007 CL Honolulu, HI SP IEEE MTT-S DE coplanar waveguide (CPW); HEMT; millimeter wave; monolithic microwave integrated circuit (MMIC); power amplifier; submillimter-wave monolithic microwave integrated circuit (S-MMIC); sub-millimeter wave ID MMIC AMPLIFIER; G-BAND; TECHNOLOGY; 35-NM; GHZ AB In this paper, we present the framework for developing the first working power amplifiers at sub-millimeter-wave frequencies. The technology is made possible by an advanced InP HEMT transistor. A three-stage power amplifier is presented, which uses a binary combiner to realize a total output periphery of 80 pm and demonstrates 12-dB gain at 335 GHz, making, this the first demonstrated sub-millimeter-wave power amplifier. Measured saturated power of 2 mW at 330 GHz is also presented, which provides a transistor power benchmark of 25 mW/mm at 330 GHz. Finally, single-stage amplifier data with large periphery transistors are presented, which demonstrates 5-dB measured gain at 230 GHz and positive measured S-21 gain to similar to 300 GHz, demonstrating that power amplifiers using larger transistors are feasible at these frequencies as well. C1 [Deal, William R.; Mei, X. B.; Radisic, Vesna; Lange, Michael D.; Yoshida, Wayne; Liu, Po-hsin; Uyeda, Jansen; Barsky, Michael E.; Lai, Richard] Northrop Grumman Corp, Redondo Beach, CA 90278 USA. [Fung, Andy; Gaier, Todd] Jet Propuls Lab, Pasadena, CA 91109 USA. RP Deal, WR (reprint author), Northrop Grumman Corp, Redondo Beach, CA 90278 USA. EM william.deal@ngc.com NR 13 TC 12 Z9 12 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD DEC PY 2007 VL 55 IS 12 BP 2719 EP 2726 DI 10.1109/TMTT.2007.910012 PN 2 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA 242IQ UT WOS:000251719200008 ER PT J AU Schwank, J Paillet, P Felix, J Buchner, S Marshall, P Duzellier, S Brown, D AF Schwank, Jim Paillet, Philippe Felix, Jim Buchner, Steve Marshall, Paul Duzellier, Sophie Brown, Dennis TI 2007 special NSREC issue of the IEEE transactions on nuclear science - Comments by the editors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Editorial Material C1 [Schwank, Jim; Felix, Jim] Sandia Natl Labs, Livermore, CA 94550 USA. [Paillet, Philippe] CEA, Gif Sur Yvette, France. [Buchner, Steve] Goddard Space Flight Ctr, NASA, QSS Grp, Greenbelt, MD 20771 USA. [Brown, Dennis] IEEE NPSS, Piscataway, NJ 08854 USA. RP Schwank, J (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 1874 EP 1874 DI 10.1109/TNS.2007.912278 PN 1 PG 1 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300002 ER PT J AU Chen, XJ Barnaby, HJ Vermeire, B Holbert, K Wright, D Pease, RL Dunham, G Platteter, DG Seiler, J McClure, S Adell, P AF Chen, X. J. Barnaby, H. J. Vermeire, B. Holbert, K. Wright, D. Pease, R. L. Dunham, G. Platteter, D. G. Seiler, J. McClure, S. Adell, P. TI Mechanisms of enhanced radiation-induced degradation due to excess molecular hydrogen in bipolar oxides SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE bipolar oxide; gated bipolar devices; hydrogen; interface traps; radiation-induced ID INTERFACE-STATE GENERATION; SI-SIO2 INTERFACE; TRAP FORMATION; MOS DEVICES; THIN-FILMS; TRANSISTORS; DIFFUSION; CENTERS; SILICON; SIO2 AB Bipolar junction test structures packaged in hermetically sealed packages with excess molecular hydrogen (H-2) showed enhanced degradation after radiation exposure. Using chemical kinetics, we propose a model that quantitatively establishes the relationship between excess H-2 and radiation-induced interface trap formation. Using environments with different molecular hydrogen concentrations, radiation experiments were performed and the experimental data showed excellent agreement with the proposed model. The results, both experimentally and theoretically, showed increased radiation induced degradation with H-2 concentration, and device degradation saturate at both high and low ends of H-2 concentrations. C1 [Chen, X. J.; Barnaby, H. J.; Vermeire, B.; Holbert, K.; Wright, D.] Arizona State Univ, Tempe, AZ 85287 USA. [Pease, R. L.] RLP Res, Los Lunas, NM 87031 USA. [Dunham, G.; Platteter, D. G.; Seiler, J.] NAVSEA Crane, Crane, IN 47522 USA. [McClure, S.; Adell, P.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chen, XJ (reprint author), Arizona State Univ, Tempe, AZ 85287 USA. EM j.chen@asu.edu; rpease@rlpresearch.com; gdunham@atd.crane.navy.mil; Platteter@atd.crane.navy.mil; seiler.john@atd.crane.navy.mil; steven.s.incclure@jpl.nasa.gov; lippe.c.adell@jpl.nasa.gov RI Holbert, Keith/B-6518-2008; OI Holbert, Keith/0000-0002-2772-1954 NR 35 TC 36 Z9 38 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 1913 EP 1919 DI 10.1109/TNS.2007.909708 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300009 ER PT J AU Xapsos, MA Stauffer, C Jordan, T Barth, JL Mewaldt, RA AF Xapsos, M. A. Stauffer, C. Jordan, T. Barth, J. L. Mewaldt, R. A. TI Model for cumulative solar heavy ion energy and linear energy transfer spectra SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE cumulative fluence; solar heavy ion; solar particle event ID ABUNDANCES; FLUENCES AB A probabilistic model of cumulative solar heavy ion energy and LET spectra is developed for spacecraft design applications. Spectra are given as a function of confidence level, mission time period during solar maximum and shielding thickness. It is shown that long-term solar heavy ion fluxes exceed galactic cosmic ray fluxes during solar maximum for shielding levels of interest. Cumulative solar heavy ion fluences should therefore be accounted for in single event effects rate calculations and in the planning of space missions. C1 [Xapsos, M. A.; Barth, J. L.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Stauffer, C.] MEI Technol Inc, Seabrook, MD 20706 USA. [Jordan, T.] EMP Consultants, Gaithersburg, MD 20885 USA. [Mewaldt, R. A.] CALTECH, Pasadena, CA 91125 USA. RP Xapsos, MA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM Michael.A.Xapsos@nasa.gov NR 13 TC 16 Z9 16 U1 1 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 1985 EP 1989 DI 10.1109/TNS.2007.910850 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300020 ER PT J AU Sutton, AK Bellini, M Cressler, JD Pellish, JA Reed, RA Marshall, PW Niu, G Vizkelethy, G Turowski, M Raman, A AF Sutton, Akil K. Bellini, Marco Cressler, John D. Pellish, Jonathon A. Reed, Robert A. Marshall, Paul W. Niu, Guofu Vizkelethy, Gyorgy Turowski, Marek Raman, Ashok TI An evaluation of transistor-layout RHBD techniques for SEE, mitigation in SiGeHBTs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE charge collection; deep trench (DT); ion beam induced charge collection (IBICC); NanoTCAD; radiation hardening by design (RHBD); silicon-germanium (SiGe); SiGeHBT; single event effects (SEE) ID INDUCED CHARGE COLLECTION; SINGLE-EVENT UPSETS; NUCLEAR MICROPROBE; SIMULATION; LOGIC; TECHNOLOGY; SUBSTRATE; CIRCUITS; DEVICES AB We investigate transistor-level layout-based techniques for SEE mitigation in advanced SiGe HBTs. The approach is based on the inclusion of an alternate reverse-biased pn junction (n-ring) designed to shunt electron charge away from the sub-collector to substrate junction. The inclusion of the n-ring affects neither the dc nor ac performance of the SiGe HBT and does not compromise its inherent multi-Mrad TID tolerance. The effects of ion strike location and angle of incidence, as well as n-ring placement, area, and bias on charge collection are investigated experimentally using a 36 MeV O-2 microbeam. The results indicate that charge shunting through the n-ring can result in up to a 90% reduction in collector collected charge for strikes outside the DT and a 18% reduction for strikes to the emitter center. 3-D transient strike simulations using NanoTCAD are used to verify the experimental observations, as well as shed insight into the underlying physical mechanisms. Circuit implications for this RHBD technique are discussed and recommendations made. C1 [Sutton, Akil K.; Bellini, Marco; Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. [Pellish, Jonathon A.; Reed, Robert A.] Vanderbilt Univ, Nashville, TN 37235 USA. [Marshall, Paul W.] NASA, GSFC, Brookneal, VA 24528 USA. [Niu, Guofu] Auburn Univ, Auburn, AL 36849 USA. [Vizkelethy, Gyorgy] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Turowski, Marek; Raman, Ashok] CFD Res Corp, Huntsville, AL 35805 USA. RP Sutton, AK (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. EM asutton@ece.gatech.edu RI Pellish, Jonathan/A-8591-2008 NR 27 TC 27 Z9 27 U1 2 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2044 EP 2052 DI 10.1109/TNS.2007.908697 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300028 ER PT J AU Ladbury, R AF Ladbury, R. TI Statistical properties of SEE rate calculation in the limits of large and small event counts SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE quality assurance; radiation effects; reliability estimation ID MICROELECTRONICS; FIGURE; MERIT AB We develop a Maximum Likelihood method for bounding single-event effect (SEE) rates at a particular confidence level. The method is useful for test planning, reliability estimates and investigating rare SEE modes and part-to-part and lot-to-lot variability. C1 [Ladbury, R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ladbury, R (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM Raymond.L.Ladbury.1@gsfc.nasa.gov NR 9 TC 10 Z9 10 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2113 EP 2119 DI 10.1109/TNS.2007.910035 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300038 ER PT J AU Berg, M Poivey, C Petrick, D Label, K Friendlich, M Stansberry, S Kim, H AF Berg, M. Poivey, C. Petrick, D. LaBel, K. Friendlich, M. Stansberry, S. Kim, H. TI Risk reduction for use of complex devices in space projects SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE risk reduction; scrubbing; Xilinx AB We present guidelines to reduce risk to an acceptable level when using complex devices in space applications. An example of application for the use of Virtex 4 Field Programmable Gate Array (FPGA) on Express Logistic Carrier (ELC) project is presented. C1 [Berg, M.; Poivey, C.; Petrick, D.; LaBel, K.; Friendlich, M.; Kim, H.] NASA, Goddard Space Flight Ctr, MEI Technologies Inc, Greenbelt, MD 20771 USA. [Stansberry, S.] ISI, Arlington, VA 22203 USA. RP Berg, M (reprint author), NASA, Goddard Space Flight Ctr, MEI Technologies Inc, Code 5614, Greenbelt, MD 20771 USA. EM melanie.d.berg@nasa.gov; christian.poivey-1@nasa.gov; david.j.petrick@nasa.gov; kenneth.a.label@nasa.gov; mark.r.friendlich@nasa.gov; hak.s.kim@nasa.gov NR 6 TC 2 Z9 2 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2137 EP 2140 DI 10.1109/TNS.2007.910291 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300042 ER PT J AU Pease, RL Platteter, DG Dunham, GW Seiler, JE Adell, PC Barnaby, HJ Chen, J AF Pease, Ronald L. Platteter, Dale G. Dunham, Gary W. Seiler, John E. Adell, Philippe C. Barnaby, Hugh J. Chen, Jie TI The effects of hydrogen in hermetically sealed packages on the total dose and dose rate response of bipolar linear circuits SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE dose rate; enhanced low-dose-rate sensitivity; hydrogen; interface traps; radiation effects; temperature transducer; total ionizing dose; voltage comparator ID RATE SENSITIVITY; PASSIVATION LAYERS; DEVICES; ELDRS; ICS AB It is demonstrated with test transistors and circuits that a small amount of hydrogen trapped in hermetically sealed packages can significantly degrade the total dose and dose rate response of bipolar linear microelectronics. In addition, we show that when exposed to an atmosphere of 100% molecular hydrogen dies with silicon nitride passivation are unaffected, whereas dies with silicon carbide or deposited oxides become very soft at high and low dose rate. C1 [Pease, Ronald L.] RLP Res, Los Lunas, NM 87031 USA. [Platteter, Dale G.; Dunham, Gary W.; Seiler, John E.] NAVSEA Crane, Crane, IN 47522 USA. [Adell, Philippe C.] Jet Propuls Lab, Pasadena, CA 91109 USA. [Barnaby, Hugh J.; Chen, Jie] Arizona State Univ, Tempe, AZ 85287 USA. RP Pease, RL (reprint author), RLP Res, Los Lunas, NM 87031 USA. EM lsrl-pease@wildblue.net; gary.dunham@navy.mi; john.seiler@navy.mil; philippe.c.adell@jpl.nasa.gov; hbarnaby@asu.edu; j.chen@asu.edu NR 14 TC 21 Z9 21 U1 0 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2168 EP 2173 DI 10.1109/TNS.2007.907870 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300047 ER PT J AU Adell, PC Barnaby, HJ Schrimpf, RD Vermeire, B AF Adell, Philippe C. Barnaby, Hugh J. Schrimpf, Ron D. Vermeire, Bert TI Band-to-band tunneling (BBT) induced leakage current enhancement in irradiated fully depleted SOI devices SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE band-to-band tunneling; fully depleted SOI; GIDL; high current regime; total ionizing dose ID TOTAL-DOSE IRRADIATION; TRANSISTOR RESPONSE; DEPENDENCE; MODEL AB We propose a model, validated with simulations, describing how hand-to-hand tunneling (BBT) affects the leakage current degradation in some irradiated fully-depleted SOI devices. It is demonstrated that the drain current dependence on total ionizing dose at negative gate bias can result from the combination of BBT and charge buildup in the BOX, including the transition to the high current state. The role of impact ionization is examined. C1 [Adell, Philippe C.] Jet Propuls Lab, Pasadena, CA 91109 USA. [Barnaby, Hugh J.; Vermeire, Bert] Arizona State Univ, Tempe, AZ 85287 USA. [Schrimpf, Ron D.] Vanderbilt Univ, Inst Space & Def Elect, Nashville, TN 37235 USA. RP Adell, PC (reprint author), Jet Propuls Lab, Pasadena, CA 91109 USA. EM philippe.c.adell@jpl.nasa.gov; hbarnaby@asu.edu; ron.schrimpf@vanderbilt.edu; Bert.Vermeire@asu.edu RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 14 TC 31 Z9 34 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2174 EP 2180 DI 10.1109/TNS.2007.911419 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300048 ER PT J AU Diestelhorst, RM Finn, S Jun, B Sutton, AK Cheng, P Marshall, PW Cressler, JD Schrimpf, RD Fleetwood, DM Gustat, H Heinemann, B Fischer, GG Knoll, D Tillack, B AF Diestelhorst, Ryan M. Finn, Steven Jun, Bongim Sutton, Akil K. Cheng, Peng Marshall, Paul W. Cressler, John D. Schrimpf, Ronald D. Fleetwood, Daniel M. Gustat, Hans Heinemann, Bernd Fischer, Gerhard G. Knoll, Dieter Tillack, Bernd TI The effects of X-ray and proton irradiation on a 200 GHz/90 GHz complementary (npn+pnp) SiGe : C HBT technology SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE complementary bipolar; heterojunction bipolar transistors; radiation effects; SiGeHBT; silicon-germanium ID HIGH-SPEED; RADIATION; TOLERANCE; POWER AB We investigate the effects of both X-ray and proton irradiation on a novel 200 GHz/90 GHz (npn/pnp) complementary SiGe:C HBT technology. The dc forward mode total dose tolerance of the pup HBTs is shown to exceed that of the npn HBTs by a significant margin after being subjected to both 63-MeV proton and 10-keV X-ray sources, while the ac characteristics of both devices exhibit no degradation up to X-ray doses as high as 1.8 Mrad(SiO2). Pre- and post-irradiation results from a current feedback operational amplifier implemented in this technology and irradiated up to a dose of 1.8 Mrad(SiO2) are presented, showing no degradation in performance metrics under two low current density bias configurations. C1 [Diestelhorst, Ryan M.; Finn, Steven; Sutton, Akil K.; Cheng, Peng; Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. [Jun, Bongim] Georgia Inst Technol, Atlanta, GA 30332 USA. [Jun, Bongim] Boeing Corp, Sylmar, CA 91342 USA. [Marshall, Paul W.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Schrimpf, Ronald D.; Fleetwood, Daniel M.] Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. [Gustat, Hans; Heinemann, Bernd; Fischer, Gerhard G.; Knoll, Dieter; Tillack, Bernd] IHP Microelect, D-15236 Frankfurt, Germany. RP Diestelhorst, RM (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. EM ryan@ece.gatecb.edu RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 15 TC 12 Z9 12 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2190 EP 2195 DI 10.1109/TNS.2007.907869 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300050 ER PT J AU Najafizadeh, L Sutton, AK Diestelhorst, RM Bellini, M Jun, B Cressler, JD Marshall, PW Marshall, CJ AF Najafizadeh, Laleh Sutton, Akil K. Diestelhorst, Ryan M. Bellini, Marco Jun, Bongim Cressler, John D. Marshall, Paul W. Marshall, Cheryl J. TI A comparison of the effects of X-ray and proton irradiation on the performance of SiGe precision voltage references SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE BiCMOS analog integrated circuits; heterojuction bipolar transistors; ionization damage; proton radiation effects; SiGe; SiGeHBTs; X-rays AB A comprehensive investigation of the performance dependencies of irradiated SiGe precision voltage reference circuits on 1) total ionizing dose (TID), 2) circuit topology, and 3) radiation source is presented. Two different bandgap voltage references were designed using a first-generation (50-GHz) SiGe BiCMOS technology platform, and subsequently exposed to X-rays at doses of 1080 krad(SiO2) and 5400 krad(SiO2). The degradation in circuit performance following X-ray irradiation depends on both the TID level and the chosen circuit topology. Measurement results show that large TID levels can significantly shift the magnitude of the output voltage. Explanations for the observed shifts re provided by utilizing detailed analyses of the two circuit topologies and considering device-to-circuit interactions. The primary factor responsible for the difference in the circuit response before and after irradiation can be attributed to the excess base leakage current in the SiGe HBT. To investigate the impact of radiation source, the circuit topology showing the worst-case degradation from the X-ray experiment was independently exposed to 63-MeV protons at the same effective TID level. A clear source dependence in the circuit response was observed, and possible origins of this behavior are identified. C1 [Najafizadeh, Laleh; Sutton, Akil K.; Diestelhorst, Ryan M.; Bellini, Marco; Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. [Jun, Bongim] Spectrolab Inc, Sylmar, CA 91342 USA. [Marshall, Paul W.; Marshall, Cheryl J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Najafizadeh, L (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. EM laleh@ece.gatech.edu; asutton@ece.gatech.edu; ryan@ece.gatech.edu; bellini@ece.gatech.edu; bjun@spectrolab.com; cressler@ece.gatech.edu; PWMarshall@aol.com; CMarshall2@aol.com NR 10 TC 9 Z9 9 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2238 EP 2244 DI 10.1109/TNS.2007.910858 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300057 ER PT J AU Bellini, M Jun, B Sutton, AK Appaswamy, AC Cheng, P Cressler, JD Marshall, PW Schrimpf, RD Fleetwood, DM El-Kareh, B Balster, S Steinmann, P Yasuda, H AF Bellini, Marco Jun, Bongim Sutton, Akil K. Appaswamy, Aravind C. Cheng, Peng Cressler, John D. Marshall, Paul W. Schrimpf, Ronald D. Fleetwood, Daniel M. El-Kareh, Badih Balster, Scott Steinmann, Philipp Yasuda, Hiroshi TI The effects of proton and x-ray irradiation on the DC and AC performance of complementary (npn+pnp) SiGeHBTs on thick-film SOI SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE C-SiGe; heterojunction bipolar transistors; radiation effects; SiGeHBT; silicon-on-insulator; SOI; TCAD ID CMOS-COMPATIBLE SOI; BIPOLAR-TRANSISTORS; RADIATION TOLERANCE; DEVICES; BJTS AB The impact of 63.3 MeV proton and 10 keV x-ray irradiation on the DC and AC performance of complementary (npn + pnp) SiGe HBTs on thick-film SOI is investigated. Proton and x-ray induced changes in the forward and inverse Gummel characteristics, the output characteristics, and avalanche multiplication are reported for both npn and pnp SiGe HBTs, at both room temperature (300 K) and at cryogenic temperatures (down to 30 K). Comparison of room temperature and cryogenic data suggests interface trap formation at two distinct physical locations in the transistors. Experimental data and calibrated TCAD simulations are used to compare the radiation response of both thick-film SOI devices and thin-film SOI SiGe HBTs. C1 [Bellini, Marco; Sutton, Akil K.; Appaswamy, Aravind C.; Cheng, Peng; Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. [Jun, Bongim] Spectrolab, Sylmar, CA 91342 USA. [Marshall, Paul W.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Schrimpf, Ronald D.; Fleetwood, Daniel M.] Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. [Balster, Scott; Steinmann, Philipp; Yasuda, Hiroshi] Texas Instruments Inc, Dallas, TX 75265 USA. RP Bellini, M (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. EM bellini@ece.gatech.edu RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 23 TC 13 Z9 14 U1 1 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2245 EP 2250 DI 10.1109/TNS.2007.909022 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300058 ER PT J AU Madan, A Jun, B Diestelhorst, RM Appaswamy, A Cressler, JD Schrimpf, RD Fleetwood, DM Marshall, PW Isaacs-Smith, T Williams, JR Koester, SJ AF Madan, Anuj Jun, Bongim Diestelhorst, Ryan M. Appaswamy, Aravind Cressler, John D. Schrimpf, Ronald D. Fleetwood, Daniel M. Marshall, Paul W. Isaacs-Smith, Tamara Williams, John R. Koester, Steven J. TI The radiation tolerance of strained Si/SiGe n-MODFETs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE bulk traps; buried-channel; displacement damage; MODFET; radiation effects; SiGe; silicon-germanium; strain ID GHZ; TRANSISTORS AB The radiation tolerance of strained Si/SiGe n-MODFETs is investigated, using 10 keV X-rays, 63 MeV high energy protons, and 4 MeV low energy protons. The effects of radiation exposure on two major device design parameters (L-SD and L-G) in T-gate Si/SiGe n-MODFETs devices are examined. A strong dependence on source-drain spacing is observed for both the DC and RF characteristics. A drift-diffusion TCAD framework is used for 2-D device simulations. We believe that the low energy protons damage the SiGe/strained-Si/SiGe lattice, leading to partial strain relaxation. The conduction band-offset (CBO) of the strained SiGe/Si heterojunction is lowered leading to higher gate current leakage. The presence of radiation-induced bulk traps in the unrelaxed SiGe layers on the device behavior is also investigated. C1 [Madan, Anuj; Jun, Bongim; Diestelhorst, Ryan M.; Appaswamy, Aravind; Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. [Schrimpf, Ronald D.] Vanderbilt Univ, Nashville, TN 37235 USA. [Marshall, Paul W.] NASA, GSFC, Brookneal, VA 24528 USA. [Isaacs-Smith, Tamara; Williams, John R.] Auburn Univ, Auburn, AL 36849 USA. [Koester, Steven J.] IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA. RP Madan, A (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. EM madan@ece.gatech.edu RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 12 TC 1 Z9 1 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2251 EP 2256 DI 10.1109/TNS.2007.907871 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300059 ER PT J AU Wroe, A Rosenfeld, A Reinhard, M Pisacane, V Ziegler, J Nelson, M Cucinotta, F Zaider, M Dicello, J AF Wroe, A. Rosenfeld, A. Reinhard, M. Pisacane, V. Ziegler, J. Nelson, M. Cucinotta, F. Zaider, M. Dicello, J. TI Solid state microdosimetry with heavy ions for space applications SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE heavy ions; microdosimetry; space ID NEUTRON-CAPTURE THERAPY; SILICON MICRODOSIMETRY; RISK-ASSESSMENT; HADRON THERAPY; RADIATION; DETECTORS; UNCERTAINTIES; SIMULATION AB This work provides information pertaining to the performance of Silicon-On-Insulator (SOI) microdosimeters in heavy ion radiation fields. SOI microdosimeters have been previously tested in light ion radiation fields for both space and therapeutic applications, however their response has not been established in high energy, heavy ion radiation fields which are experienced in space. Irradiations were completed at the NASA Space Radiation Laboratory at BNL using 0.6 GeV/u Fe and 1.0 GeV/u Ti ions. Energy deposition and lineal energy spectra were obtained with this device at various depths within a Lucite phantom along the central axis of the beam. The response of which was compared with existing proportional counter data to assess the applicability of SOI microdosimeters to future deployments in space missions. C1 [Wroe, A.; Rosenfeld, A.] Univ Wollongong, Ctr Med Radiat Res, Wollongong, NSW 2087, Australia. [Reinhard, M.] Australian Nucl Sci & Technol Org, Menai, NSW 2234, Australia. [Pisacane, V.; Ziegler, J.; Nelson, M.; Dicello, J.] USN Acad, Annapolis, MD 21401 USA. [Cucinotta, F.] NASA, Radiat Res Dept, Houston, TX 77058 USA. [Zaider, M.] Mem Sloan Kettering Canc Ctr, Dept Med Phys, New York, NY 10021 USA. RP Wroe, A (reprint author), Univ Wollongong, Ctr Med Radiat Res, Wollongong, NSW 2087, Australia. EM ajw16@uow.edu.au; anatoly@uow.edu.au; mrz@ansto.gov.au; pisacane@usna.edu; ziegler@aya.yale.edu; nelson@usna.edu; francis.a.cucinotta@nasa.gov; zaiderm@mskcc.org; dicello@usna.edu RI Rosenfeld, Anatoly/D-1989-2014; OI Zaider, Marco/0000-0002-5113-7862 NR 25 TC 12 Z9 12 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2264 EP 2271 DI 10.1109/TNS.2007.910037 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300061 ER PT J AU Gersey, B Aghara, S Wilkins, R Wedeking, J Dwivedi, RC AF Gersey, B. Aghara, S. Wilkins, R. Wedeking, J. Dwivedi, R. C. TI Comparison of a tissue equivalent and a silicon equivalent proportional counter microdosimeter to high-energy proton and neutron fields SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE high-energy neutron; microdosimetry; radiation detectors; silicon microdosimetry ID SINGLE-EVENT UPSET; ENVIRONMENTS; DETECTOR; DEVICES AB A tissue equivalent and a silicon equivalent proportional counter microdosimeter were exposed to eight progressively hardened neutron energy spectra at the LANSCE ICE House facility and to 70 MeV protons. Selected dosimetric results are compared. C1 Prairie View A&M Univ, NASA, Ctr Appl Radiat Res, Prairie View, TX 77446 USA. RP Gersey, B (reprint author), Prairie View A&M Univ, NASA, Ctr Appl Radiat Res, Prairie View, TX 77446 USA. EM buddyhme@hotmail.com; skaghara@pvamu.edu; rtwilkins@pvamu.edu; JWedeking@pvamu.edu; redwivedi@pvamu.edu NR 24 TC 3 Z9 3 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2276 EP 2281 DI 10.1109/TNS.2007.910295 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300063 ER PT J AU Reed, RA Weller, RA Mendenhall, MH Lauenstein, JM Warren, KM Pellish, JA Schrimpf, RD Sierawski, BD Massengill, LW Dodd, PE Shaneyfelt, MR Felix, JA Schwank, JR Haddad, NF Lawrence, RK Bowman, JH Conde, R AF Reed, R. A. Weller, R. A. Mendenhall, M. H. Lauenstein, J. -M. Warren, K. M. Pellish, J. A. Schrimpf, R. D. Sierawski, B. D. Massengill, L. W. Dodd, P. E. Shaneyfelt, M. R. Felix, J. A. Schwank, J. R. Haddad, N. F. Lawrence, R. K. Bowman, J. H. Conde, R. TI Impact of ion energy and species on single event effects analysis SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE nuclear reactions; single event effects (SEE); single event effect rate ID SCREENED COULOMB SCATTERING; CROSS-SECTION MEASUREMENTS; SEU HARDENED SRAM; NUCLEAR-REACTIONS; UPSET; TECHNOLOGY; GEANT4; MODEL; RATES; TCAD AB Experimental evidence and Monte-Carlo simulations for several technologies show that accurate SEE response predictions depend on a detailed description of the variability of radiation events (e.g., nuclear reactions), as opposed to the classical single-valued LET parameter. Rate predictions conducted with this Simulation framework exhibit excellent agreement with the average observed SEU rate on NASA's MESSENGER mission to Mercury, while a prediction from the traditional IRPP method, which does not include the contribution from ion-ion reactions, falls well below the observed rate. While rate predictions depend on availability of technology information, the approach described here is sufficiently flexible that reasonably accurate results describing the response to irradiation can be obtained even in the absence of detailed information about the device geometry and fabrication process. C1 [Reed, R. A.; Weller, R. A.; Pellish, J. A.; Schrimpf, R. D.; Massengill, L. W.] Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. [Mendenhall, M. H.] Vanderbilt Univ, Nashville, TN 37235 USA. [Lauenstein, J. -M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Warren, K. M.; Sierawski, B. D.] Vanderbilt Univ, Inst Space & Def Elect, Nashville, TN 37203 USA. [Dodd, P. E.; Shaneyfelt, M. R.; Felix, J. A.; Schwank, J. R.] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Haddad, N. F.; Lawrence, R. K.; Bowman, J. H.] BAE Syst, Manassas, VA 20110 USA. [Conde, R.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RP Reed, RA (reprint author), Vanderbilt Univ, Dept Elect Engn & Comp Sci, 221 Kirkland Hall, Nashville, TN 37235 USA. EM robert.reed@vanderbilt.edu RI Pellish, Jonathan/A-8591-2008; Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 27 TC 57 Z9 62 U1 2 U2 18 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2312 EP 2321 DI 10.1109/TNS.2007.909901 PN 1 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300068 ER PT J AU Pellish, JA Reed, RA Sutton, AK Weller, RA Carts, MA Marshall, PW Marshall, CJ Krithivasan, R Cressler, JD Mendenhall, MH Schrimpf, RD Warren, KM Sierawski, BD Niu, GF AF Pellish, Jonathan A. Reed, Robert A. Sutton, Akil K. Weller, Robert A. Carts, Martin A. Marshall, Paul W. Marshall, Cheryl J. Krithivasan, Ramkumar Cressler, John D. Mendenhall, Marcus H. Schrimpf, Ronald D. Warren, Kevin M. Sierawski, Brian D. Niu, Guofu F. TI A generalized SiGe HBT single-event effects model for on-orbit event rate calculations SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE deep trench isolation; Geant4; geosynchronous orbit; low-earth orbit; rate prediction; silicon-germanium HBT; single-event upset ID HETEROJUNCTION BIPOLAR-TRANSISTORS; HEAVY-ION; NUCLEAR-REACTIONS; CHARGE COLLECTION; SILICON DEVICES; CROSS-SECTION; MICROPROBE; CIRCUITS; LOGIC; UPSET AB This work draws on experimental and simulation results to derive a generalized SEU response model for bulk SiGe HBTs. The model was validated using published heavy ion and new proton data gathered from high-speed HBT digital logic integrated circuits fabricated in the IBM 5AM SiGe BiCMOS process. Calibrating to heavy ion data was sufficient to reproduce the proton data without further adjustment. The validated model is used to calculate upset event rates for low-earth and geosynchronous orbits under typical conditions. C1 [Pellish, Jonathan A.; Reed, Robert A.; Weller, Robert A.; Schrimpf, Ronald D.] Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. [Sutton, Akil K.; Krithivasan, Ramkumar; Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. [Carts, Martin A.; Marshall, Cheryl J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Marshall, Paul W.] NASA, Brookneal, VA 24528 USA. [Mendenhall, Marcus H.; Warren, Kevin M.; Sierawski, Brian D.] Vanderbilt Univ, Inst Space & Def Elect, Nashville, TN 37235 USA. [Niu, Guofu F.] Auburn Univ, Dept Elect & Comp Engn, Auburn, AL 36849 USA. RP Pellish, JA (reprint author), Dept Elect Engn & Comp Sci, 221 Kirkland Hall, Nashville, TN 37235 USA. EM jonathan.pellish@ieee.org RI Pellish, Jonathan/A-8591-2008; Krithivasan, Ramkumar/D-3549-2011; Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 37 TC 14 Z9 15 U1 3 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2322 EP 2329 DI 10.1109/TNS.2007.909987 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300069 ER PT J AU Varadharajaperumal, M Niu, G Wei, XY Zhang, T Cressler, JD Reed, RA Marshall, PW AF Varadharajaperumal, Muthubalan Niu, Guofu Wei, Xiaoyun Zhang, Tong Cressler, John D. Reed, Robert A. Marshall, Paul W. TI 3-D simulation of SEU hardening of SiGeHBTs using shared dummy collector SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE critical charge; deep trench isolation (DTI); dummy collector; radiation hardening by design (RHBD); SiGeHBT; single event upset (SEU); SRH recombination ID INDUCED CHARGE COLLECTION; SINGLE; CIRCUIT; RATES AB This paper presents a SEU hardening approach that uses a dummy collector to reduce charge collection in the main transistor. The dummy collector is obtained using the silicon space between adjacent HBTs. It is obtained without any process modification or area penalty. The simulations are performed for normal and angled strikes. The hardened device shows significant reduction in charge collection due to sharing of diffusive charge collection by the dummy collector. Multiple HBT arrays of regular and hardened HBT are simulated to study the simultaneous charge collection in multiple HBTs. With hardening, charge collection in multiple devices is suppressed considerably for normal and angled strikes as the shared dummy collector collects a large amount of charge. C1 [Varadharajaperumal, Muthubalan; Niu, Guofu; Wei, Xiaoyun; Zhang, Tong] Auburn Univ, Alabama Microelect Sci & Technol Ctr, Dept Elect & Comp Engn, Auburn, AL 36849 USA. [Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. [Reed, Robert A.] Vanderbilt Univ, Nashville, TN 37212 USA. [Marshall, Paul W.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Varadharajaperumal, M (reprint author), Auburn Univ, Alabama Microelect Sci & Technol Ctr, Dept Elect & Comp Engn, Auburn, AL 36849 USA. EM niuguof@auburn.edu NR 14 TC 13 Z9 14 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2330 EP 2337 DI 10.1109/TNS.2007.910290 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300070 ER PT J AU Laird, JS Onoda, S Hirao, T Edmonds, L Ohshima, T AF Laird, Jamie S. Onoda, Shinobu Hirao, Toshio Edmonds, Larry Ohshima, Takeshi TI The role of ion track structure on high-injection carrier dynamics in high-speed Si and III-V optoelectronic sensors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE III-V; GaAs; heavy ion; high frequency; high-injection effects; ion track structure; optoelectronics; picosecond laser; Si; space-charge screening; transient current; ultrafast ID SINGLE-EVENT TRANSIENTS; CHARGE COLLECTION; HEAVY-ION; PULSED-LASER; GAAS-MESFETS; SILICON; ENERGY; PHOTODETECTORS; TEMPERATURE; DEPENDENCE AB The role of ion track structure on high-injection carrier dynamics in a high-speed GaAs p(+) - n - n(+) sensor is investigated using laser and high-energy heavy ion microbeams. The results are compared to similar data collected on a Si p+ - n - n+ device where Space Charge Screening Effects (SCSE) result in transient shape being dependent on ion track structure. The results collected are discussed within the framework of the Edmonds charge collection model and generalized to III-V optoelectronic sensors. C1 [Laird, Jamie S.; Edmonds, Larry] CALTECH, Jet Propuls Lab, Pasadena, CA 91101 USA. [Onoda, Shinobu; Hirao, Toshio; Ohshima, Takeshi] Japan Atom Energy Agcy, Dept Severe Environm Mat, Gunma 3701292, Japan. RP Laird, JS (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91101 USA. EM Jamie.S.Laird@jpl.nasa.gov RI Laird, Jamie/A-7683-2011 NR 43 TC 7 Z9 7 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2384 EP 2393 DI 10.1109/TNS.2007.911421 PN 1 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300077 ER PT J AU Hubbs, JE Marshall, PW Marshall, CJ Gramer, ME Maestas, D Garcia, JP Dole, GA Anderson, AA AF Hubbs, John E. Marshall, Paul W. Marshall, Cheryl J. Gramer, Mark E. Maestas, Diana Garcia, John P. Dole, Gary A. Anderson, Amber A. TI Lateral diffusion length changes in HgCdTe detectors in a proton environment SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE HgCdTe detectors; non-ionizing energy loss (NIEL); proton radiation effects ID DISPLACEMENT DAMAGE; NIEL AB This paper presents a study of the performance degradation in a proton environment of long wavelength infrared (LWIR) HgCdTe detectors. The energy dependence of the Non-Ionizing Energy Loss (NIEL) in HgCdTe provides a framework for estimating the responsivity degradation in LWIR HgCdTe detectors due to on-orbit exposure from protons. Banded detector arrays of different detector designs were irradiated at proton energies of 7, 12, and 63 MeV. These banded detector arrays allowed insight into how the fundamental detector parameters degraded in a proton environment at the three different proton energies. Measured data demonstrated that the detector responsivity degradation at 7 MeV is 5 times larger than the degradation at 63 MeV. Comparison of the responsivity degradation at the different proton energies suggests that the atomic Columbic interaction of the protons with the HgCdTe detector is likely the primary mechanism responsible for the degradation in responsivity at proton energies below 30 MeV. C1 [Hubbs, John E.; Gramer, Mark E.; Maestas, Diana; Garcia, John P.; Dole, Gary A.] Ball Aerosp & Technol Corp, Albuquerque, NM 87185 USA. [Marshall, Cheryl J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Anderson, Amber A.] AFRL VSSS, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA. RP Hubbs, JE (reprint author), Ball Aerosp & Technol Corp, Albuquerque, NM 87185 USA. EM jhubbs@ieee.org; pwmar-shall@aol.com; cmarshal2@aol.com; amber.anderson@kirtland.af.mil NR 17 TC 12 Z9 12 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2435 EP 2443 DI 10.1109/TNS.2007.910329 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300084 ER PT J AU Howe, CL Weller, RA Reed, RA Sierawski, BD Marshall, PW Marshall, CJ Mendenhall, MH Schrimpf, RD Hubbs, JE AF Howe, Christina L. Weller, Robert A. Reed, Robert A. Sierawski, Brian D. Marshall, Paul W. Marshall, Cheryl J. Mendenhall, Marcus H. Schrimpf, Ronald D. Hubbs, John E. TI Distribution of proton-induced transients in silicon focal plane arrays SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE energy deposited; event rate; focal plane array; Geant4; Monte Carlo; pile up ID DETECTOR AB Proton-induced energy deposition in a silicon P-i-N focal plane array is analyzed with Monte Carlo based simulations. These simulations include all physical processes, including events resulting from multiple particles incident on a single pixel, to describe the experimental data accurately. Post-processing of Monte Carlo simulations is done to account for the effects of pile up (multiple hits on a single pixel during one integration time) and non-radiation-induced noise in experiment. The results are compared with experimental data, and demonstrate how direct ionization dominates the cross section, yet fluctuations in dE/dx cause a broad range of energy depositions not addressed by an average LET calculation. An event rate is predicted for a full space proton flux and the dominance of direct ionization is shown and compared to computation using constant LET methods in CREME96. This comparison shows that at lower energies, CREME96 sufficiently predicts the event rate, but at higher energies a high fidelity simulation method is needed to capture the distribution. C1 [Howe, Christina L.; Weller, Robert A.; Reed, Robert A.; Schrimpf, Ronald D.] Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. [Weller, Robert A.; Reed, Robert A.; Sierawski, Brian D.; Schrimpf, Ronald D.] Vanderbilt Univ, Inst Space & Def Elect, Nashville, TN 37235 USA. [Marshall, Cheryl J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Mendenhall, Marcus H.] Vanderbilt Univ, Free Elect Laser Ctr, Nashville, TN 37235 USA. [Hubbs, John E.] Ball Aerosp & Technol Corp, Kirtland AFB, NM 87117 USA. RP Howe, CL (reprint author), Vanderbilt Univ, Dept Elect Engn & Comp Sci, 221 Kirkland Hall, Nashville, TN 37235 USA. EM christina.l.howe@vanderbilt.edu RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 13 TC 2 Z9 2 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2444 EP 2449 DI 10.1109/TNS.2007.909511 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300085 ER PT J AU Johnston, AH Miyahira, TF AF Johnston, A. H. Miyahira, T. F. TI LED technologies for Optocouplers: Fundamental issues and hardness assurance SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE hardness assurance; light-emitting diode; optocoupler; radiation effects ID LIGHT-EMITTING-DIODES; PROTON DAMAGE; RADIATION DEGRADATION; ENERGY-DEPENDENCE; GAAS AB Radiation damage is examined for several different LED technologies used in optocouplers, including those with wavelengths near 700 nm that are used in radiation-tolerant devices, and have not been widely studied. Forward diode characteristics and reverse recovery time measurements are examined as potential parameters for hardness assurance. C1 [Johnston, A. H.; Miyahira, T. F.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Johnston, AH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM allan.h.johnston@jpl.nasa.gov; tetsuo.f.miyahira@jpl.nasa.gov NR 19 TC 3 Z9 3 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2450 EP 2456 DI 10.1109/TNS.2007.909910 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300086 ER PT J AU Buchner, S Rapchun, DA Moseley, H Meyer, SE Oldham, T Ray, K Tuttle, J Quinn, E Buchanan, E Bloom, D Hait, T Pearce, M Beamer, A AF Buchner, S. Rapchun, David A. Moseley, Harvey Meyer, Stephen E. Oldham, Tim Ray, Knute Tuttle, Jim Quinn, Ed Buchanan, Ernie Bloom, Dave Hait, Tom Pearce, Mike Beamer, A. TI Response of a MEMS microshutter operating at 60 K to ionizing radiation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE insulators; low temperature; micro-electro-mechanical system; total ionizing dose ID SYSTEMS MEMS; ACCELEROMETERS AB Total ionizing dose (TID) measurements at low temperature (60 K) of a Micro-Electro-Mechanical System (MEMS) Microshutter Array (MSA) indicate that exposing the MSA to ionizing radiation causes some of the shutters to stop operating properly. The number of non-functional shutters depends on the applied bias. With increasing dose, the number of micro-shutters that become non-functional increases. C1 [Buchner, S.] Perot Syst, Seabrook, MD 20706 USA. Global Sci & Technol Inc, Greenbelt, MD 20771 USA. [Moseley, Harvey; Meyer, Stephen E.; Oldham, Tim; Tuttle, Jim; Bloom, Dave; Hait, Tom; Beamer, A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Ray, Knute] MEI, Lanham, MD 20706 USA. [Quinn, Ed] Orbital Sci, Dulles, VA 20166 USA. [Buchanan, Ernie] Sci Syst & Applicat Inc, Lanham, MD 20706 USA. [Pearce, Mike] Swales Aerosp, Beltsville, MD 20705 USA. RP Buchner, S (reprint author), Perot Syst, Seabrook, MD 20706 USA. EM sbuchner@pop500.gsfc.nasa.gov RI Moseley, Harvey/D-5069-2012 NR 11 TC 9 Z9 9 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2463 EP 2467 DI 10.1109/TNS.2007.910040 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300088 ER PT J AU Chen, WJ Varanasi, N Pouget, V Barnaby, HJ Vermeire, B Adell, PC Copani, T Fouillat, P AF Chen, Wenjian Varanasi, Niha Pouget, Vincent Barnaby, Hugh J. Vermeire, Bert Adell, Philippe C. Copani, Tino Fouillat, Pascal TI Impact of VCO topology on SET induced frequency response SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE amplitude modulation; frequency modulation; phase noise; single-event transients; voltage-controlled oscillator (VCO) ID SINGLE-EVENT TRANSIENTS; CIRCUITS AB Laser experiments performed on two SiGe voltage controlled oscillator (VCO) circuit topologies show different output spectrums. Analytical models demonstrate that spectral response is determined by design features that impact modulated amplitude or frequency characteristic of transient signals. Further analysis of the two circuits shows the DC bias condition dependence on the topology during laser strikes, which is the main cause of the frequency and amplitude modulation of the transient output signal. C1 [Chen, Wenjian; Varanasi, Niha; Barnaby, Hugh J.; Vermeire, Bert; Copani, Tino] Arizona State Univ, Tempe, AZ 85287 USA. [Pouget, Vincent; Fouillat, Pascal] IMS Lab, F-33405 Talence, France. [Adell, Philippe C.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chen, WJ (reprint author), Arizona State Univ, Tempe, AZ 85287 USA. EM wenjian.chen@asu.edu; vincent.pouget@ims-bordeaus.fr; philippe.c.adell@jpl.nasa.gov NR 7 TC 10 Z9 15 U1 3 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2500 EP 2505 DI 10.1109/TNS.2007.911422 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300094 ER PT J AU Bernard, MF Dusseau, L Buchner, S McMorrow, D Ecoffet, R Boch, J Vaille, JR Schrimpf, RD LaBel, K AF Bernard, M. F. Dusseau, L. Buchner, S. McMorrow, D. Ecoffet, R. Boch, J. Vaille, J. -R. Schrimpf, R. D. LaBel, K. TI Impact of total ionizing dose on the analog single event transient sensitivity of a linear bipolar integrated circuit SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE analog single event transients; bipolar integrated circuits; linear voltage comparator; pulsed-laser testing; total dose ID VOLTAGE COMPARATOR; LASER AB Total ionizing dose (TID) strongly affects the Single Event Transient (SET) sensitivity of a bipolar linear voltage comparator (LM139). The general rule that transistors in the non-conducting state are the most sensitive to SETs was verified, with some exceptions. The mechanisms responsible for those exceptions were identified and explained using circuit analysis. In the non typical behavior, a correlation of the degradation of the amplifier stages with the shape of the transient output signal was established. Following total dose exposure the SETs generally exhibit a reduction in amplitude due to the degradation of the slew rate. However, in some cases the transient signal is amplified because degradation of either the current source or of the current gain of some transistors forces the output transistor to the edge of conduction, so that it behaves like a voltage amplifier and amplifies the parasitic transient signal. Laser testing demonstrates that ASET sensitivity also is affected by TID degradation of transistors that are not directly hit by the laser. C1 [Bernard, M. F.; Dusseau, L.; Boch, J.; Vaille, J. -R.] Univ Montpellier 2, CNRS, UMR 5214, IES, F-34095 Montpellier 5, France. [Buchner, S.; LaBel, K.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. [McMorrow, D.] USN, Res Lab, Washington, DC 20375 USA. [Ecoffet, R.] Ctr Natl Etud Spatiales, F-31401 Toulouse 9, France. [Schrimpf, R. D.] Vanderbilt Univ, Nashville, TN 37235 USA. RP Bernard, MF (reprint author), Univ Montpellier 2, CNRS, UMR 5214, IES, F-34095 Montpellier 5, France. EM bernard@cem2.univ-montp2.fr RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 9 TC 17 Z9 17 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2534 EP 2540 DI 10.1109/TNS.2007.910229 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300098 ER PT J AU Irom, F Nguyen, DN AF Irom, Farokh Nguyen, Duc N. TI Single event effect characterization of high density commercial NAND and NOR nonvolatile flash memories SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE catastrophic; destructive; dielectric gate rupture; micro-dose; nonvolatile memory ID THIN GATE OXIDES; HARD ERRORS; ION; BREAKDOWN; IRRADIATION; RUPTURE; SRAMS AB Heavy ion single-event measurements on a variety of high density commercial NAND and NOR flash memories were reported. Three SEE phenomena were investigated: SEUs, SEFIs, and catastrophic loss of ability to erase and write to the device. Although for all devices under test SEUs and SEFIs were observed, these commercial high densities devices appear to be much less susceptible than typical flash devices that have been tested lately. A new high current phenomenon in the high density NAND flash memories and charge pump failure in the NOR flash memory are discussed. C1 [Irom, Farokh; Nguyen, Duc N.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Irom, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM farokh.irom@jpl.nasa.gov; duc.n.nguyen@jpl.nasa.gov NR 24 TC 39 Z9 42 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2547 EP 2553 DI 10.1109/TNS.2007.909984 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300100 ER PT J AU Scheick, LZ Selva, LE AF Scheick, Leif Z. Selva, Luis E. TI Effect of dose history on SEGR properties of power MOSFETS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 44th Annual IEEE International Nuclear and Space Radiation Effects Conference CY JUL 23-27, 2007 CL Waikiki Beach, HI SP IEEE DE power MOSFET; proton dose; single event gate rupture ID EVENT GATE-RUPTURE; BREAKDOWN VOLTAGE; RADIATION; IRRADIATION; DEVICES; ENERGY; DAMAGE; MODEL AB We present data that show that proton radiation damage can influence the single event gate rupture response of a power MOSFET. A primary phenomenon of single event gate rupture, the drain to gate threshold at which single event gate rupture occurs, drops as a function of device dosage. The shift in the threshold voltage correlates the best with the drop in the voltage at which SEGR occurs. The increase in the field strength due to trapped charges within the oxide during a charge collection event is suspected as the mechanism. C1 [Scheick, Leif Z.; Selva, Luis E.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Scheick, LZ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM leif.z.scheick@jpl.nasa.gov NR 25 TC 6 Z9 6 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2007 VL 54 IS 6 BP 2568 EP 2575 DI 10.1109/TNS.2007.910127 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 242RV UT WOS:000251744300103 ER PT J AU Rumsey, CL AF Rumsey, Christopher L. TI Apparent transition behavior of widely-used turbulence models SO INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW LA English DT Article; Proceedings Paper CT 5th Conference on Turbulence, Heat and Mass Transfer CY 2006 CL Dubrovnik, CROATIA DE turbulence model; transition ID BYPASS TRANSITION; EQUATION; PREDICTION; CLOSURE; FLOWS AB The Spalart-Allmaras and the Menter k-omega SST turbulence models are shown to have the undesirable characteristic that, for fully turbulent external flow computations, a transition region can occur whose extent varies with grid density. Extremely fine two-dimensional grids over the front portion of an airfoil are used to demonstrate the effect. As the grid density is increased, the laminar region near the nose becomes larger. In the Spalart-Allmaras model this behavior is due to convergence to a laminar-behavior fixed point that occurs in practice when freestream turbulence is below some threshold. It is the result of a feature purposefully added to the original model in conjunction with a special trip function. This degenerate fixed point can also cause non-uniqueness regarding where transition initiates on a given grid. Consistent fully turbulent results can easily be achieved by either using a freestream turbulence level higher than the threshold or by making a simple change to one of the model constants. Near the area where turbulence initiates, the SST model exhibits sensitivity to numerical resolution, but its solutions are unique on a given grid. Inconsistent apparent transition behavior with grid refinement in this case does not stem from the presence of a degenerate fixed point. A nullcline analysis is used to visualize the local behavior of the model. (C) 2007 Elsevier Inc. All rights reserved. C1 NASA Langley Res Ctr, Computat Aerosci Branch, Hampton, VA 23681 USA. RP Rumsey, CL (reprint author), NASA Langley Res Ctr, Computat Aerosci Branch, MS 128, Hampton, VA 23681 USA. EM c.l.rumsey@nasa.gov NR 29 TC 28 Z9 29 U1 1 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0142-727X EI 1879-2278 J9 INT J HEAT FLUID FL JI Int. J. Heat Fluid Flow PD DEC PY 2007 VL 28 IS 6 BP 1460 EP 1471 DI 10.1016/j.ijheatfluidflow.2007.04.003 PG 12 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 247SD UT WOS:000252099400022 ER PT J AU Turyshev, SG Israelsson, UE Shao, M Yu, N Kusenko, A Wright, EL Everitt, CWF Kasevich, M Lipa, JA Mester, JC Reasenberg, RD Walsworth, RL Ashby, N Gould, H Paik, HJ AF Turyshev, Slava G. Israelsson, Ulf E. Shao, Michael Yu, Nan Kusenko, Alexander Wright, Edward L. Everitt, C. W. Francis Kasevich, Mark Lipa, John A. Mester, John C. Reasenberg, Robert D. Walsworth, Ronald L. Ashby, Neil Gould, Harvey Paik, Ho Jung TI Space-based research in fundamental physics and quantum technologies SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop From Quantum to Cosmos - Fundamental Physics Research in Space CY MAY 21-24, 2006 CL Warrenton, VA DE fundamental physics in space; general and special theories of relativity; Standard Model extensions; gravitational waves; cosmology; astroparticle physics; cold atoms; quantum sensors; science policy ID INVERSE-SQUARE LAW; ELECTRIC-DIPOLE MOMENT; WARM DARK-MATTER; HIGHER-DIMENSIONAL THEORIES; EQUIVALENCE PRINCIPLE; NEUTRINO OSCILLATIONS; GENERAL-RELATIVITY; STERILE NEUTRINOS; ATOM INTERFEROMETRY; STRING THEORY AB Space offers unique experimental conditions and a wide range of opportunities to explore the foundations of modern physics with an accuracy far beyond that of ground-based experiments. Space-based experiments today can uniquely address important questions related to the fundamental laws of Nature. In particular, high-accuracy physics experiments in space can test relativistic gravity and probe the physics beyond the Standard Model; they can perform direct detection of gravitational waves and are naturally suited for investigations in precision cosmology and astroparticle physics. In addition, atomic physics has recently shown substantial progress in the development of optical clocks and atom interferometers. If placed in space, these instruments could turn into powerful high-resolution quantum sensors greatly benefiting fundamental physics. We discuss the current status of space-based research in fundamental physics, its discovery potential, and its importance for modern science. We offer a set of recommendations to be considered by the upcoming National Academy of Sciences' Decadal Survey in Astronomy and Astrophysics. In our opinion, the Decadal Survey should include space-based research in fundamental physics as one of its focus areas. We recommend establishing an Astronomy and Astrophysics Advisory Committee's interagency "Fundamental Physics Task Force" to assess the status of both ground- and space-based efforts in the field, to identify the most important objectives, and to suggest the best ways to organize the work of several federal agencies involved. We also recommend establishing a new NASA-led interagency program in fundamental physics that will consolidate new technologies, prepare key instruments for future space missions, and build a strong scientific and engineering community. Our goal is to expand NASA's science objectives in space by including "laboratory research in fundamental physics" as an element in the agency's ongoing space research efforts. C1 [Turyshev, Slava G.; Israelsson, Ulf E.; Shao, Michael; Yu, Nan] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Kusenko, Alexander; Wright, Edward L.] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. [Everitt, C. W. Francis; Kasevich, Mark; Lipa, John A.; Mester, John C.] Stanford Univ, Dept Phys, Hansen Expt Phys Lab, Stanford, CA 94305 USA. [Reasenberg, Robert D.; Walsworth, Ronald L.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Ashby, Neil] Univ Colorado, Dept Phys, Boulder, CO 80309 USA. [Gould, Harvey] Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. [Paik, Ho Jung] Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Turyshev, SG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM turyshev@jpl.nasa.gov NR 303 TC 28 Z9 28 U1 1 U2 10 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 EI 1793-6594 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD DEC PY 2007 VL 16 IS 12A BP 1879 EP 1925 DI 10.1142/S0218271807011760 PG 47 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258EA UT WOS:000252850000002 ER PT J AU Iess, L Asmar, S AF Iess, Luciano Asmar, Sami TI Probing space - Time in the solar system: From Cassini to BepiColombo SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop From Quantum to Cosmos - Fundamental Physics Research in Space CY MAY 21-24, 2006 CL Warrenton, VA DE relativistic gravity; radio science; spacecraft tracking ID GENERAL-RELATIVITY AB Spacecraft radio science techniques can be used for precision solar system tests of relativistic gravity, as was demonstrated by the measurement of the Doppler shift of radio signals with the Cassini mission. Similar experiments are planned for the BepiColombo mission to Mercury. Recent theoretical developments based on string theory and inflationary cosmologies link the validity of general relativity to the expansion of the Universe and indicate that violations may be within the reach of future, precise experiments. In spite of the uncertainty of the theoretical scenarios, the motivations for further tests of gravitational theories are stronger then ever: string theory, new cosmological observations, the hypotheses of dark matter and dark energy, all point to the need for a new and more profound understanding of the Universe and its laws, including the laws of gravity. This paper describes experiments for probing space-time in the solar system with the Cassini and BepiColombo missions, and discusses the experimental limitations of microwave systems used for these tests, including attitude motion and nongravitational accelerations of the spacecraft, propagation noise, and mechanical noise of ground antenna. C1 [Iess, Luciano] Univ Roma La Sapienza, Rome, Italy. [Asmar, Sami] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Iess, L (reprint author), Univ Roma La Sapienza, Rome, Italy. EM Luciano.Iess@uniroma1.it; sami.asmar@jpl.nasa.gov RI IESS, Luciano/F-4902-2011 OI IESS, Luciano/0000-0002-6230-5825 NR 18 TC 15 Z9 15 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD DEC PY 2007 VL 16 IS 12A BP 2117 EP 2126 DI 10.1142/S0218271807011449 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258EA UT WOS:000252850000020 ER PT J AU Merkowitz, SM Dabney, PW Livas, JC Mcgarry, JF Neumann, GA Zagwodzki, TW AF Merkowitz, Stephen M. Dabney, Philip W. Livas, Jeffrey C. Mcgarry, Jan F. Neumann, Gregory A. Zagwodzki, Thomas W. TI Laser ranging for gravitational, lunar and planetary science SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop From Quantum to Cosmos - Fundamental Physics Research in Space CY MAY 21-24, 2006 CL Warrenton, VA DE lunar ranging; general relativity; Moon; Mars ID EQUIVALENCE PRINCIPLE; GRAVITY; TESTS; MARS AB More precise lunar and Martian ranging will enable unprecedented tests of Einstein's theory of general relativity as well as lunar and planetary science. NASA is currently planning several missions to return to the Moon, and it is natural to consider if precision laser ranging instruments should be included. New advanced retroreflector arrays at carefully chosen landing sites would have an immediate positive impact on lunar and gravitational studies. Laser transponders are currently being developed that may offer an advantage over passive ranging, and could be adapted for use on Mars and other distant objects. Precision ranging capability can also be combined with optical communications for an extremely versatile instrument. In this paper we discuss the science that can be gained by improved lunar and Martian ranging along with several technologies that can be used for this purpose. C1 [Merkowitz, Stephen M.; Dabney, Philip W.; Livas, Jeffrey C.; Mcgarry, Jan F.; Neumann, Gregory A.; Zagwodzki, Thomas W.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Merkowitz, SM (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM Stephen.M.Merkowitz@nasa.gov RI Livas, Jeffrey/D-2994-2012; McGarry, Jan/C-4109-2013; Dabney, Philip/C-9976-2013; Merkowitz, Stephen/D-6680-2012; Neumann, Gregory/I-5591-2013 OI Merkowitz, Stephen/0000-0002-0412-4209; Neumann, Gregory/0000-0003-0644-9944 NR 20 TC 13 Z9 13 U1 0 U2 9 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD DEC PY 2007 VL 16 IS 12A BP 2151 EP 2164 DI 10.1142/S0218271807011565 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258EA UT WOS:000252850000023 ER PT J AU Turyshev, SG Williams, JG AF Turyshev, Slava G. Williams, James G. TI Space-based tests of gravity with laser ranging SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop From Quantum to Cosmos - Fundamental Physics Research in Space CY MAY 21-24, 2006 CL Warrenton, VA DE tests of gravity; lunar laser ranging; fundamental physics ID EQUIVALENCE PRINCIPLE; MOON AB Existing capabilities of laser ranging, optical interferometry, and metrology, in combination with precision frequency standards, atom-based quantum sensors, and drag-free technologies, are critical for space-based tests of fundamental physics; as a result of the recent progress in these disciplines, the entire area is poised for major advances. Thus, accurate ranging to the Moon and Mars will provide significant improvements in several gravity tests, namely the equivalence principle, geodetic precession, PPN parameters beta and., and possible variation of the gravitational constant G. Other tests will become possible with the development of an optical architecture that allows one to proceed from meter to centimeter to millimeter range accuracies on interplanetary distances. Motivated by anticipated accuracy gains, we discuss the recent renaissance in lunar laser ranging and consider future relativistic gravity experiments with precision laser ranging over interplanetary distances. C1 [Turyshev, Slava G.; Williams, James G.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Turyshev, SG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM turyshev@jpl.nasa.gov NR 32 TC 35 Z9 36 U1 0 U2 5 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD DEC PY 2007 VL 16 IS 12A BP 2165 EP 2179 DI 10.1142/S0218271807011838 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258EA UT WOS:000252850000024 ER PT J AU Turyshev, SG Shao, M AF Turyshev, Slava G. Shao, Michael TI Laser Astrometric Test of Relativity: Science, technology and mission design SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop From Quantum to Cosmos - Fundamental Physics Research in Space CY MAY 21-24, 2006 CL Warrenton, VA DE tests of general relativity; interferometric astrometry; laser ranging ID POST-NEWTONIAN FORMALISM; ANGULAR POWER SPECTRUM; TENSOR-SCALAR THEORIES; GRAVITATIONAL DEFLECTION; GENERAL-RELATIVITY; 2ND-ORDER CONTRIBUTIONS; COSMOLOGICAL CONSTANT; GRAVITY; LIGHT; SUPERNOVAE AB The Laser Astrometric Test of Relativity (LATOR) experiment is designed to explore the general theory of relativity in close proximity to the Sun-the most intense gravitational environment in the solar system. Using independent time series of highly accurate measurements of the Shapiro time delay (interplanetary laser ranging accurate to 3 mm at similar to 2 AU) and interferometric astrometry (accurate to 0.01 picoradian), LATOR will measure gravitational deflection of light by the solar gravity with an accuracy of one part in a billion-a factor of similar to 30,000 better than what is currently available. LATOR will perform a series of highly accurate tests in its search for cosmological remnants of the scalar field in the solar system. We present the science, technology and mission design for the LATOR mission. C1 [Turyshev, Slava G.; Shao, Michael] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Turyshev, SG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM turyshev@jpl.nasa.gov; mshao@huey.jpl.nasa.gov NR 38 TC 8 Z9 8 U1 1 U2 3 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 EI 1793-6594 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD DEC PY 2007 VL 16 IS 12A BP 2191 EP 2203 DI 10.1142/S0218271807011747 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258EA UT WOS:000252850000026 ER PT J AU Kolodziejczak, JJ Mester, J AF Kolodziejczak, Jeffery J. Mester, John TI Satellite test of the equivalence principle: Overview and progress SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop From Quantum to Cosmos - Fundamental Physics Research in Space CY MAY 21-24, 2006 CL Warrenton, VA DE equivalence principle; instrumentation; gravity; fundamental physics AB STEP, the Satellite Test of the Equivalence Principle, is reviewed and the current status of the project is discussed. This space- based experiment will test the universality of free fall and is designed to advance the present state of knowledge by over five orders of magnitude. The international STEP collaboration is pursuing a development plan to improve and verify the technology readiness of key systems. We discuss recent advances with an emphasis on accelerometer fabrication and tests. Critical technologies successfully demonstrated in flight by the Gravity Probe B mission also contribute to progress. C1 [Kolodziejczak, Jeffery J.] NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. [Mester, John] Stanford Univ, WW Hansen Expt Phys Lab, STEP, Stanford, CA 94305 USA. RP Kolodziejczak, JJ (reprint author), NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, 320 Sparkman Dr,XD 12, Huntsville, AL 35805 USA. EM Jeffery.Kolodziejczak-1@nasa.gov; mester@step.stanford.edu NR 12 TC 2 Z9 2 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD DEC PY 2007 VL 16 IS 12A BP 2215 EP 2225 DI 10.1142/S0218271807011486 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258EA UT WOS:000252850000028 ER PT J AU Bosco, A Cantone, C Dell'Agnello, S Delle Monache, GO Franceschi, MA Garattini, M Napolitano, T Ciufolini, I Agneni, A Graziani, F Ialongo, P Lucantoni, A Paolozzi, A Peroni, I Sindoni, G Bellettini, G Tauraso, R Pavlis, EC Currie, DG Rubincam, DP Arnold, DA Matzner, R Slabinski, VJ AF Bosco, A. Cantone, C. Dell'Agnello, S. Delle Monache, G. O. Franceschi, M. A. Garattini, M. Napolitano, T. Ciufolini, I. Agneni, A. Graziani, F. Ialongo, P. Lucantoni, A. Paolozzi, A. Peroni, I. Sindoni, G. Bellettini, G. Tauraso, R. Pavlis, E. C. Currie, D. G. Rubincam, D. P. Arnold, D. A. Matzner, R. Slabinski, V. J. TI Probing gravity in NEO's with high-accuracy laser-ranged test masses SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop From Quantum to Cosmos - Fundamental Physics Research in Space CY MAY 21-24, 2006 CL Warrenton, VA DE gravitomagnetism; climatic test; thermal analysis ID SATELLITES AB Gravity can be studied in detail in near Earth orbits NEO's using laser-ranged test masses tracked with few-mm accuracy by ILRS. The two LAGEOS satellites have been used to measure frame dragging (a truly rotational effect predicted by GR) with a 10% error. A new mission and an optimized, second generation satellite, LARES (I. Ciufolini PI), is in preparation to reach an accuracy of 1% or less on frame dragging, to measure some PPN parameters, to test the 1/r(2) law in a very weak. field and, possibly, to test select models of unified theories (using the perigee). This requires a full thermal analysis of the test mass and an accurate knowledge of the asymmetric thermal thursts due to the radiation emitted by the Sun and Earth. A Space Climatic Facility (SCF) has been built at INFN-LNF (Frascati, Italy) to perform this experimental program on LAGEOS and LARES prototypes. It consists of a 2 m x 1 m cryostat, simulators of the Sun and Earth radiations and a versatile thermometry system made of discrete probes and an infrared digital camera. The SCF commissioning is well underway. A test of all its subsystems has been successfully completed on August 4, 2006, using a LAGEOS 3 x 3 retroreflector array built at LNF. This prototype has been thermally modeled in detail with a commercial simulation software. We expect to demonstrate the full functionality of the SCF with the thermal characterization of this LAGEOS array by the beginning of September 2006. C1 [Bosco, A.; Cantone, C.; Dell'Agnello, S.; Delle Monache, G. O.; Franceschi, M. A.; Garattini, M.; Napolitano, T.] Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. [Ciufolini, I.] Univ Lecce, I-73100 Lecce, Italy. [Ciufolini, I.] Ist Nazl Fis Nucl, I-73100 Lecce, Italy. [Agneni, A.; Graziani, F.; Ialongo, P.; Lucantoni, A.; Paolozzi, A.; Peroni, I.; Sindoni, G.] Univ Roma La Sapienza, Sch Aerosp Engn, I-00184 Rome, Italy. [Bellettini, G.; Tauraso, R.] Univ Roma Tor Vergata, Dept Math, I-00133 Rome, Italy. [Pavlis, E. C.] Univ Maryland, Baltimore, MD 21201 USA. [Pavlis, E. C.] NASA, Baltimore, MD USA. [Currie, D. G.] Univ Maryland, College Pk, MD 20742 USA. [Rubincam, D. P.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Matzner, R.] Univ Texas Austin, Austin, TX 78712 USA. [Slabinski, V. J.] USN Observ, Washington, DC 20392 USA. RP Bosco, A (reprint author), Ist Nazl Fis Nucl, Lab Nazl Frascati, POB 13, I-00044 Frascati, Italy. EM Simone.DellAgnello@Inf.infn.it RI Rubincam, David/D-2918-2012; OI Tauraso, Roberto/0000-0002-5619-3513 NR 6 TC 18 Z9 18 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD DEC PY 2007 VL 16 IS 12A BP 2271 EP 2285 DI 10.1142/S0218271807011322 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258EA UT WOS:000252850000032 ER PT J AU Stecker, FW AF Stecker, F. W. TI TESTING RELATIVITY AT HIGH ENERGIES USING SPACEBORNE DETECTORS SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article DE Relativity; gamma rays; quantum gravity; cosmic rays; space telescopes AB The Gamma-Ray Large Area Space Telescope (GLAST), to be launched in the fall of 2007, will measure the spectra of distant extragalactic sources of high energy.rays, particularly active galactic nuclei and gamma-ray bursts. GLAST can look for energy dependent gamma-ray propagation effects from such sources as a signal of Lorentz invariance violation (LIV). These sources should also exhibit the high energy cutoffs predicted to be the result of intergalactic annihilation interactions with low energy photons having a flux level as determined by various astronomical observations. Such annihilations result in electron-positron pair production above a threshold energy given by 2m(e) in the center-of-momentum frame of the system, assuming Lorentz invariance. If Lorentz invariance is violated, this threshold can be significantly raised, changing the predicted absorption turnover in the observed spectrum of the sources. Stecker and Glashow have shown that the existence of such absorption features in the spectra of extragalactic sources puts constraints on LIV. Such constraints have important implications for some quantum gravity and large extra dimension models. Future spaceborne detectors dedicated to measuring gamma-ray polarization can look for birefringence effects as a possible signal of loop quantum gravity. As shown by Coleman and Glashow, a much smaller amount of LIV has potential implications for possibly suppressing the "GZK cutoff" predicted to be caused by the interactions of cosmic rays having multijoule energies with photons of the 2.7K cosmic background radiation in intergalactic space. Owing to the rarity of such ultrahigh energy cosmic rays, their spectra are best studied by a UV-sensitive satellite detector which looks down on a large volume of the Earth's atmosphere to study the nitrogen fluorescence tracks of giant air showers produced by these ultrahigh energy cosmic rays. We discuss here, in particular, a two-satellite mission called OWL, which would be suited for making such studies. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. RP Stecker, FW (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. RI Stecker, Floyd/D-3169-2012 FU NASA [ATP03-0000-0057] FX Part of this work was supported by NASA grant ATP03-0000-0057. NR 44 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 EI 1793-6594 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD DEC PY 2007 VL 16 IS 12B BP 2343 EP 2355 DI 10.1142/S021827180701170X PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA V11XQ UT WOS:000207564700003 ER PT J AU Hahn, I Day, P Bumble, B Leduc, HG AF Hahn, I. Day, P. Bumble, B. Leduc, H. G. TI ADVANCED HYBRID SQUID MULTIPLEXER CONCEPT FOR THE NEXT GENERATION OF ASTRONOMICAL INSTRUMENTS SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article DE SQUID; multiplexer; bolometer AB The Superconducting Quantum Interference Device (SQUID) has been used and proposed often to read out low-temperature detectors for astronomical instruments. A multiplexed SQUID readout for currently envisioned astronomical detector arrays, which will have tens of thousands of pixels, is still challenging with the present technology. We present a new, advanced multiplexing concept and its prototype development that will allow for the readout of 1,000-10,000 detectors with only three pairs of wires and a single microwave coaxial cable. C1 [Hahn, I.; Day, P.; Bumble, B.; Leduc, H. G.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hahn, I (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Inseob.Hahn@jpl.nasa.gov FU Jet Propulsion Laboratory, California Institute of Technology, under National Aeronautics and Space Administration FX This work was supported by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. NR 6 TC 1 Z9 1 U1 1 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD DEC PY 2007 VL 16 IS 12B BP 2407 EP 2412 DI 10.1142/S0218271807011413 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA V11XQ UT WOS:000207564700009 ER PT J AU Maleki, L Prestage, J AF Maleki, Lute Prestage, John TI SPACETIME: PROBING FOR 21ST CENTURY PHYSICS WITH CLOCKS NEAR THE SUN SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article DE General relativity; fundamental constants; SpaceTime mission AB We will describe a space mission study based on three high-precision atomic clocks, flying to within six solar radii of the Sun, for a test of the possible variation of the fine structure constant, alpha. The three clocks are based on transitions in three different atomic species. Measurement of the drift in ratios between the frequencies generated by each clock will probe for the variation of alpha. Since the response of each atomic species to alpha change in alpha has a specific signature, this measurement will provide sensitive and unambiguous results. The sensitivity of this experiment to a changing alpha is comparable to the sensitivity of recent tests based on observational astronomy, exceeding the geophysical bounds on alpha variations. Thus, the experiment will provide a compelling reaffirmation or refutation of astronomical observations, and represents an important test of the models aimed at bridging physics of the quantum to the cosmos. C1 [Maleki, Lute; Prestage, John] CALTECH, Jet Prop Lab, Quantum Sci & Technol Grp, Pasadena, CA 91109 USA. RP Maleki, L (reprint author), CALTECH, Jet Prop Lab, Quantum Sci & Technol Grp, Pasadena, CA 91109 USA. EM Lute.Maleki@jpl.nasa.gov; John.D.Prestage@jpl.nasa.gov NR 23 TC 1 Z9 1 U1 0 U2 3 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD DEC PY 2007 VL 16 IS 12B BP 2525 EP 2536 DI 10.1142/S0218271807011541 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA V11XQ UT WOS:000207564700020 ER PT J AU Osman, S Moissl, C Hosoya, N Briegel, A Mayilraj, S Satomi, M Venkateswaran, K AF Osman, Shariff Moissl, Christine Hosoya, Naofumi Briegel, Ariane Mayilraj, Shanmugam Satomi, Masataka Venkateswaran, Kasthuri TI Tetrasphaera remsis sp nov., isolated from the regenerative enclosed life support module simulator (REMS) air system SO INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY LA English DT Article ID CANDIDATUS NOSTOCOIDA-LIMICOLA; ACTIVATED-SLUDGE; GENUS TETRASPHAERA; TOMOGRAPHY; BACTERIUM AB Two Gram-positive, coccoid, non-spore-forming bacteria (strains 3-M5-R-4(T) and 3-M5-R-7), cells of which formed diploid, tetrad and cluster arrangements, were isolated from air of the Regenerative Enclosed Life Support Module Simulator system. On the basis of 16S rRNA gene sequence similarity, these strains were shown to belong to the family Intrasporangiaceae and were related to members of the genus Tetrasphaera, with similarities to the seven known species of the genus Tetrasphaera of 96.71-97.76%. The fatty acid profile supported affiliation of these novel isolates to the genus Tetrasphaera, although larger amounts of octadecanoic acid (C-18:0) and cis-9-octadecenoic acid (C-18:1) were observed in the isolates, thus enabling them to be differentiated from other Tetrasphaera species. In addition, DNA-DNA hybridization studies indicated that these strains belonged to a novel species that could be readily distinguished from its nearest neighbour, Tetrasphaera japonica DSM 13192(T), which had less than 20% DNA-DNA relatedness. Physiological and biochemical tests showed few phenotypic differences, but genotypic analysis enabled these gelatin-liquefying strains to be differentiated from the seven Tetrasphaera species. The strains described in this study therefore represent a novel species, for which the name Tetrasphaera remsis sp. nov. is proposed; the type strain is 3-M5-R-4(T) (=ATCC BAA-1496(T) =CIP 109413(T)). C1 [Osman, Shariff; Moissl, Christine; Hosoya, Naofumi; Venkateswaran, Kasthuri] CALTECH, Biotechnol & Planetary Protect Grp, Jet Prop Lab, Pasadena, CA 91109 USA. [Moissl, Christine] Univ Regensburg, Lehrstuhl Mikrobiol & Archaeezentrum, D-93053 Regensburg, Germany. [Briegel, Ariane] CALTECH, Div Biol, Pasadena, CA 91125 USA. [Mayilraj, Shanmugam] Inst Microbial Technol, Microbial Type Culture Collect & Gene Bank, Chandigarh 160036, India. [Satomi, Masataka] Fisheries Res Agcy, Natl Res Inst Fisheries Sci, Yokohama, Kanagawa 2368648, Japan. RP Venkateswaran, K (reprint author), CALTECH, Biotechnol & Planetary Protect Grp, Jet Prop Lab, Pasadena, CA 91109 USA. EM kjvenkat@jpl.nasa.gov RI Shanmugam, Mayilraj/F-8807-2010; Moissl-Eichinger, Christine/A-6682-2015 OI Moissl-Eichinger, Christine/0000-0001-6755-6263 NR 15 TC 5 Z9 5 U1 0 U2 2 PU SOC GENERAL MICROBIOLOGY PI READING PA MARLBOROUGH HOUSE, BASINGSTOKE RD, SPENCERS WOODS, READING RG7 1AG, BERKS, ENGLAND SN 1466-5026 J9 INT J SYST EVOL MICR JI Int. J. Syst. Evol. Microbiol. PD DEC PY 2007 VL 57 BP 2749 EP 2753 DI 10.1099/ijs.0.65137-0 PN 12 PG 5 WC Microbiology SC Microbiology GA 245YX UT WOS:000251975800004 PM 18048719 ER PT J AU Johnson, S AF Johnson, Stephen TI Into the black: JPL and the American Space Program SO ISIS LA English DT Book Review C1 [Johnson, Stephen] Univ Colorado, NASA Marshall Space Flight Ctr, Ares Crew Launch Vehicle Program, Colorado Springs, CO 80907 USA. RP Johnson, S (reprint author), Univ Colorado, NASA Marshall Space Flight Ctr, Ares Crew Launch Vehicle Program, Colorado Springs, CO 80907 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0021-1753 J9 ISIS JI Isis PD DEC PY 2007 VL 98 IS 4 BP 881 EP 882 DI 10.1086/529341 PG 4 WC History & Philosophy Of Science SC History & Philosophy of Science GA 250OQ UT WOS:000252310300078 ER PT J AU Matloff, GL Johnson, L Maccone, C AF Matloff, Gregory L. Johnson, Les Maccone, Claudio TI Helios and Prometheus: A solar/nuclear outer-solar system mission SO JBIS-JOURNAL OF THE BRITISH INTERPLANETARY SOCIETY LA English DT Article DE heliopause; solar sail; Kuiper Belt objects; radioisotope electric propulsion ID PROPULSION; SPACE AB A 2-3 decade mission is proposed with a solar-sail spacecraft approaching the Sun within 0.2 AU. After sail unfurlment at the perihelion of an initially elliptical solar orbit and the completion of acceleration, the spacecraft splits into two components. One part is a scientific payload bound for the heliopause; the second is designed to rendezvous with a Kuiper Belt Object and decelerates across the solar system using Radioisotope-Electric Propulsion. C1 CUNY, New York city Coll Technol, Phys Dept, Brooklyn, NY 11216 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Matloff, GL (reprint author), CUNY, New York city Coll Technol, Phys Dept, 300 Jay St, Brooklyn, NY 11216 USA. EM GMatloff@citytech.cuny.edu NR 9 TC 2 Z9 2 U1 0 U2 1 PU BRITISH INTERPLANETARY SOC PI LONDON PA 27-29 S LAMBETH RD, LONDON SW8 1SZ, ENGLAND SN 0007-084X J9 JBIS-J BRIT INTERPLA JI JBIS-J. Br. Interplanet. Soc. PD DEC PY 2007 VL 60 IS 12 BP 439 EP 442 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Engineering; Astronomy & Astrophysics; Geology GA 230PB UT WOS:000250887300002 ER PT J AU Offermann, D Jarisch, M Schmidt, H Oberheide, J Grossmann, KU Gusev, O Russell, JM Mlynczak, MG AF Offermann, D. Jarisch, M. Schmidt, H. Oberheide, J. Grossmann, K. U. Gusev, O. Russell, J. M., III Mlynczak, M. G. TI The "wave turbopause" SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT 2rd IAGA/ICMA on Vertical Coupling in the Atmosphere/Ionosphere System CY SEP 18-22, 2006 CL Varna, BULGARIA SP Int Assoc Geomagnetism & Aeronomy, Int Commisson Middle Atmosphere, Int Union Geodesy Geophysics, Int Union Radio Sci, US Air Force European Off Aerospace Dev DE mesosphere; wave damping; turbopause; HAMMONIA; CRISTA; SABER ID ENERGY-DISSIPATION RATES; MIDDLE ATMOSPHERE; LOWER THERMOSPHERE; GRAVITY-WAVE; MESOPAUSE REGION; SOLAR-CYCLE; MESOSPHERE; RADAR; MODEL; TURBULENCE AB The "wave turbopause" is defined as the mesospheric altitude level where the temperature fluctuation field indicates a substantial increase in wave amplitudes in the vertical direction. The turbopause altitude is analyzed on the basis of four years of SABER data (2002-2005, Version 1.06). Substantial seasonal and latitudinal variations are found, with some interannual variability also present. Seasonal changes are annual at high latitudes, semi-annual at low latitudes, and a mixture of both at middle latitudes. Southern hemisphere data are similar as in the North if shifted by half a year. Latitudinal variations show a minimum in the tropics and two relative maxima at middle latitudes. The "wave turbopause" is found near to zero-wind lines or low-wind zones (zonal wind). It is compared to rocket and other measurements, and interesting similarities are obtained. The wave turbopause can also be found in the HAMMONIA GCM. A preliminary analysis shows results similar to those of the SABER measurements. (c) 2007 Elsevier Ltd. All rights reserved. C1 [Offermann, D.; Jarisch, M.; Oberheide, J.; Grossmann, K. U.; Gusev, O.] Univ Wuppertal, Wuppertal, Germany. [Schmidt, H.] Max Planck Inst Meteorol, Hamburg, Germany. [Russell, J. M., III] Hampton Univ, Hampton, VA USA. [Mlynczak, M. G.] NASA, Langley Res Ctr, Hampton, VA USA. RP Offermann, D (reprint author), Univ Wuppertal, Wuppertal, Germany. EM offerm@uni-wuppertal.de RI Oberheide, Jens/C-6156-2011; Mlynczak, Martin/K-3396-2012; Schmidt, Hauke/J-4469-2013 OI Oberheide, Jens/0000-0001-6721-2540; Schmidt, Hauke/0000-0001-8271-6456 NR 37 TC 15 Z9 15 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD DEC PY 2007 VL 69 IS 17-18 BP 2139 EP 2158 DI 10.1016/j.jastp.2007.05.012 PG 20 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 244BU UT WOS:000251841800005 ER PT J AU Shepherd, MG Wu, DL Fedulina, IN Gurubaran, S Russell, JM Mlynczak, MG Shepherd, GG AF Shepherd, M. G. Wu, D. L. Fedulina, I. N. Gurubaran, S. Russell, J. M. Mlynczak, M. G. Shepherd, G. G. TI Stratospheric warming effects on the tropical mesospheric temperature field SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT 2rd IAGA/ICMA on Vertical Coupling in the Atmosphere/Ionosphere System CY SEP 18-22, 2006 CL Varna, BULGARIA SP Int Assoc Geomagnetism & Aeronomy, Int Commisson Middle Atmosphere, Int Union Geodesy Geophysics, Int Union Radio Sci, US Air Force European Off Aerospace Dev DE tropical mesosphere; temperature; stratospheric warming; satellites ID ATMOSPHERE RESEARCH SATELLITE; WIND IMAGING INTERFEROMETER; STATIONARY PLANETARY-WAVES; LOWER THERMOSPHERE; DATA ASSIMILATION; SABER EXPERIMENT; WINTER; VARIABILITY; UARS; OSCILLATION AB Temperature observations at 20-90 km height and 5-15 degrees N during the winter of 1992-1993, 1993-1994 and 2003-2004, from the Wind Imaging Interferometer (WINDII) and Microwave Limb Sounder (MLS) experiments on the Upper Atmosphere Research Satellite (UARS) satellite and the Sounding the Atmosphere using Broadband Emission Radiometry (SABER) experiment on the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) satellite are analyzed together with MF radar winds and UK Meteorological Office (UKMO) assimilated fields. Mesospheric cooling is observed at the time of stratospheric warming at the tropics correlative with stratospheric warming events at middle and high latitudes. Planetary waves m = 1 with periods of 4-5, 6-8, 10 and 12-18 days are found to dominate the period. Westward 7- and 16-day waves at the tropics appear enhanced by stationary planetary waves during sudden stratospheric warming events. (c) 2007 Elsevier Ltd. All rights reserved. C1 [Shepherd, M. G.; Shepherd, G. G.] York Univ, Ctr Res Earth & Space Sci, N York, ON M3J 1P3, Canada. [Wu, D. L.] CALTECH, Microwave Atmos Sc, Pasadena, CA 91109 USA. [Fedulina, I. N.] Inst Ionosphere, Alma Ata 480020, Kazakhstan. [Gurubaran, S.] Indian Inst Geomagnetism, Equatorial Geophys Res Lab, Tirunelveli 627011, India. [Russell, J. M.] Hampton Univ, Hampton, VA USA. [Mlynczak, M. G.] NASA, Langley Res Ctr, Hampton, VA USA. RP Shepherd, MG (reprint author), York Univ, Ctr Res Earth & Space Sci, 4700 Keele St, N York, ON M3J 1P3, Canada. EM mshepher@yorku.ca RI Mlynczak, Martin/K-3396-2012; Gurubaran, Subramanian/C-6694-2013; Wu, Dong/D-5375-2012 NR 69 TC 35 Z9 36 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD DEC PY 2007 VL 69 IS 17-18 BP 2309 EP 2337 DI 10.1016/j.jastp.2007.04.009 PG 29 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 244BU UT WOS:000251841800015 ER PT J AU Lopez-Gonzalez, M Garcia-Comas, M Rodriguez, E Lopez-Puertas, M Shepherd, MG Shepherd, GG Sargoytchev, S Aushev, VM Smith, SM Mlynczak, MG Russell, JM Brown, S Cho, YM Wiens, RH AF Lopez-Gonzalez, M. J. Garcia-Comas, M. Rodriguez, E. Lopez-Puertas, M. Shepherd, M. G. Shepherd, G. G. Sargoytchev, S. Aushev, V. M. Smith, S. M. Mlynczak, M. G. Russell, J. M. Brown, S. Cho, Y. -M. Wiens, R. H. TI Ground-based mesospheric temperatures at mid-latitude derived from O-2 and OH airglow SATI data: Comparison with SABER measurements SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT 2rd IAGA/ICMA on Vertical Coupling in the Atmosphere/Ionosphere System CY SEP 18-22, 2006 CL Varna, BULGARIA SP Int Assoc Geomagnetism & Aeronomy, Int Commisson Middle Atmosphere, Int Union Geodesy Geophysics, Int Union Radio Sci, US Air Force European Off Aerospace Dev DE mesosphere; airglow; temperature; instruments ID ROTATIONAL TEMPERATURES; SEASONAL-VARIATIONS; MESOPAUSE REGION; MIDDLE ATMOSPHERE; THERMAL STRUCTURE; HYDROXYL AIRGLOW; CO 41-DEGREES-N; LOW-LATITUDES; IMAGER; CLIMATOLOGY AB Rotational temperatures obtained from the O-2 Atmospheric (0-1) nightglow band and from the OH (6-2) band, with a Spectral Airglow Temperature Imager (SATI) instrument at Sierra Nevada Observatory (37.06 degrees N, 3.38 degrees W) are presented. A revision of the temperatures obtained from the Q branch of the (6-2) Meinel band has been undertaken. First, new experimental Einstein coefficients for these lilies have been introduced and the temperatures derived from the Q lilies (1, 2 and 3) of the (6-2) OH Meinel band have been compared to those deduced from the P lines (2 and 4) of the same band of spectra taken by a spectrograph at Boston University. The new set of SATI data has been used to analyse the seasonal behaviour of the inesospheric and lower thermospheric temperatures. Atmospheric temperatures deduced from SATI and from satellite observations with the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board the TIMED satellite, have also been compared. SABER temperatures at 95 kin are slightly warmer (about 2.5 K) than SATI temperatures while at 87 km they are slightly colder (about 5.7 K). Also, similar patterns of seasonal and day to day variations are found in the temperatures retrieved from both instruments at the latitude of 37 degrees N. (c) 2007 Elsevier Ltd. All rights reserved. C1 [Lopez-Gonzalez, M. J.; Garcia-Comas, M.; Rodriguez, E.; Lopez-Puertas, M.] CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain. [Shepherd, M. G.; Shepherd, G. G.; Sargoytchev, S.; Brown, S.; Cho, Y. -M.] York Univ, CRESS, N York, ON M3J 1P3, Canada. [Aushev, V. M.] Minist Educ & Sci, Inst Ionosphere, Alma Ata, Kazakhstan. [Smith, S. M.] Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. [Mlynczak, M. G.] NASA, Langley Res Ctr, Hampton, VA USA. [Russell, J. M.] Hampton Univ, Hampton, VA USA. RP Lopez-Gonzalez, M (reprint author), CSIC, Inst Astrofis Andalucia, PO Box 3004, E-18080 Granada, Spain. EM mariajose@iaa.es RI Mlynczak, Martin/K-3396-2012; Lopez Puertas, Manuel/M-8219-2013; Garcia-Comas, Maya/E-4050-2014 OI Lopez Puertas, Manuel/0000-0003-2941-7734; Garcia-Comas, Maya/0000-0003-2323-4486 NR 36 TC 17 Z9 17 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD DEC PY 2007 VL 69 IS 17-18 BP 2379 EP 2390 DI 10.1016/j.jastp.2007.07.004 PG 12 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 244BU UT WOS:000251841800019 ER PT J AU Liu, WT Xie, XS Niiler, PP AF Liu, W. Timothy Xie, Xiaosu Niiler, Pearn P. TI Ocean-atmosphere interaction over agulhas extension meanders SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; TROPICAL INSTABILITY WAVES; EXTRATROPICAL SST ANOMALIES; EASTERN EQUATORIAL PACIFIC; BOUNDARY-LAYER RESPONSE; SATELLITE MEASUREMENTS; SOUTHERN-OCEAN; BULK PARAMETERIZATION; VORTICITY BALANCE; RETURN CURRENT AB Many years of high-resolution measurements by a number of space-based sensors and from Lagrangian drifters became available recently and are used to examine the persistent atmospheric imprints of the semipermanent meanders of the Agulhas Extension Current (AEC), where strong surface current and temperature gradients are found. The sea surface temperature (SST) measured by the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and the chlorophyll concentration measured by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) support the identification of the meanders and related ocean circulation by the drifters. The collocation of high and low magnitudes of equivalent neutral wind (ENW) measured by Quick Scatterometer (QuikSCAT), which is uniquely related to surface stress by definition, illustrates not only the stability dependence of turbulent mixing but also the unique stress measuring capability of the scatterometer. The observed rotation of ENW in opposition to the rotation of the surface current clearly demonstrates that the scatterometer measures stress rather than winds. The clear differences between the distributions of wind and stress and the possible inadequacy of turbulent parameterization affirm the need of surface stress vector measurements, which were not available before the scatterometers. The opposite sign of the stress vorticity to current vorticity implies that the atmosphere spins down the current rotation through momentum transport. Coincident high SST and ENW over the southern extension of the meander enhance evaporation and latent heat flux, which cools the ocean. The atmosphere is found to provide negative feedback to ocean current and temperature gradients. Distribution of ENW convergence implies ascending motion on the downwind side of local SST maxima and descending air on the upwind side and acceleration of surface wind stress over warm water ( deceleration over cool water); the convection may escalate the contrast of ENW over warm and cool water set up by the dependence of turbulent mixing on stability; this relation exerts a positive feedback to the ENW-SST relation. The temperature sounding measured by the Atmospheric Infrared Sounder ( AIRS) is consistent with the spatial coherence between the cloud-top temperature provided by the International Satellite Cloud Climatology Project (ISCCP) and SST. Thus ocean mesoscale SST anomalies associated with the persistent meanders may have a long-term effect well above the midlatitude atmospheric boundary layer, an observation not addressed in the past. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. RP Liu, WT (reprint author), CALTECH, Jet Prop Lab, MS 300-323, Pasadena, CA 91109 USA. EM liu@pacific.jpl.nasa.gov NR 66 TC 45 Z9 45 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 2007 VL 20 IS 23 BP 5784 EP 5797 DI 10.1175/2007JCLI1732.1 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 239RG UT WOS:000251534800008 ER PT J AU Nettles, AT Gregory, ED Jackson, JR AF Nettles, A. T. Gregory, E. D. Jackson, J. R. TI Using the climbing drum peel (CDP) test to obtain a G(IC) value for Core/Face sheet bonds SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE honeycomb; fracture toughness; mode I delamination; double cantilever beam; climbing drum peel ID SANDWICH STRUCTURES; FRACTURE; DELAMINATION; HONEYCOMB; ADHESION AB A method of measuring the mode I (peeling) fracture toughness of core/face sheet bonds in sandwich structures is desired, particularly with the widespread use of models that need this data as input. This study examined if a mode I critical strain energy release rate, G(IC), can be obtained from the climbing drum peel (CDP) test. The CDP test is relatively simple to perform and does not rely on measuring small crack lengths such as required by the more commonly used double cantilever beam (DCB) test. Simple energy methods were used to calculate G(IC) from CDP test data on composite face sheets bonded to a honeycomb core. Face sheet thicknesses from 2 to 5 plies (0.51-1.27 mm) were tested to examine the upper and lower bounds on face sheet thickness requirements. Suggestions on conducting the test and on modifying the CDP apparatus to test composite face sheets (as opposed to metallic) are also presented. Results from the study suggest that the CDP test, with certain provisions, can be used to find the G(IC) value of a core/face sheet bond. C1 NASA, George C Marshall Space Flight Ctr, Damage Tolerance Branch, Huntsville, AL 35812 USA. Univ Kansas, Dept Aerosp Engn, Lawrence, KS 66045 USA. NASA, George C Marshall Space Flight Ctr, Non Met Mat Branch, Huntsville, AL 35812 USA. RP Nettles, AT (reprint author), NASA, George C Marshall Space Flight Ctr, Damage Tolerance Branch, Huntsville, AL 35812 USA. EM Alan.t.nettles@nasa.gov NR 11 TC 5 Z9 5 U1 2 U2 3 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PD DEC PY 2007 VL 41 IS 24 BP 2863 EP 2876 DI 10.1177/0021998307079974 PG 14 WC Materials Science, Composites SC Materials Science GA 233BV UT WOS:000251066300001 ER PT J AU Wang, C Newman, TS Gallagher, DL AF Wang, Cuilan Newman, Timothy S. Gallagher, Dennis L. TI Plasmapause equatorial shape determination via the Minimum L Algorithm: Description and evaluation SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID RING CURRENT; EUV IMAGES; PLASMASPHERE; DENSITY; MODEL; MAGNETOSPHERE; EVOLUTION AB Algorithms for determination of the equatorial shape of the plasmapause using NASA IMAGE Extreme Ultraviolet ( EUV) imagery are considered. Focus is on the Minimum L Algorithm, which operates without human intervention given a single EUV image in which the plasmasphere silhouette boundary has been identified. For each line of sight ( LOS) through pixels on the plasmasphere silhouette boundary, the algorithm first finds all magnetic dipole field lines intersected by the LOS and then returns as the plasmasphere's boundary the field line with the minimum L value. An analysis of the reasonableness, applicability, and accuracy of the algorithm is presented, and it is contrasted with the well-known Edge Algorithm ( Roelof and Skinner, 2000). A revised version of the Edge Algorithm is also introduced. Application of all three algorithms to real EUV imagery is demonstrated. C1 Univ Alabama, Dept Comp Sci, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Newman, TS (reprint author), Univ Alabama, Dept Comp Sci, TH N300, Huntsville, AL 35899 USA. EM tnewman@cs.uah.edu NR 22 TC 6 Z9 6 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 2007 VL 112 IS A12 AR A12201 DI 10.1029/2006JA012202 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 237BY UT WOS:000251349000001 ER PT J AU Nghiem, SV Leshkevich, GA AF Nghiem, Son V. Leshkevich, George A. TI Satellite SAR remote sensing of Great Lakes ice cover, part 1. Ice backscatter signatures at C band SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE Great Lakes; ice; Synthetic Aperture Radar (SAR); ERS-2; RADARSAT; C-band polarimetric scatterometer; classification; remote sensing ID WIND-GENERATED WAVES; ST-CLAIR RIVER; MICHIGAN; SCATTEROMETRY AB For remote sensing of Great Lakes ice cover, afield experiment campaign was conducted in the 1997 winter season across the Straits of Mackinac and Lake Superior. The campaign was coordinated in two expeditions on two different United States Coast Guard icebreaker vessels, the Biscayne Bay in February and the Mackinaw in March. Aboard these icebreakers, the Jet Propulsion Laboratory C-band polarimetric scatterometer was used to measure backscatter signatures of various ice types and open water at incidence angles from 0 degrees to 60 degrees. The radar measurements include incidence angles and polalrizations of spaceborne Synthetic Aperture Radars (SAR) on ERS, RADARSAT, and Envisat satellites. The radar data together with in situ measurements form a signature library that can be used to interpret SAR data for ice classification and mapping. Results are presented for backscatter signatures of Great Lakes ice types from thin lake ice to thick brash ice with different snow-cover and surface conditions. The signature library indicates that several ice types can be identified with multi-polarization SAR data; however, single-polarization data can result in misclassification of ice and open water at different ranges of incidence angle and wind conditions. For incidence angles larger than 30 degrees, thick brash ice, the most difficult for icebreaking operations and the most hazardous for ship navigation, can be uniquely identified by co-polarized backscatter for all wind conditions below the gale force. C1 [Nghiem, Son V.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Leshkevich, George A.] NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Nghiem, SV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM son.v.nghiem@jpl.nasa.gov NR 26 TC 12 Z9 12 U1 1 U2 8 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2205 COMMONWEALTH BLVD, ANN ARBOR, MI 48105 USA SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PD DEC PY 2007 VL 33 IS 4 BP 722 EP 735 DI 10.3394/0380-1330(2007)33[722:SSRSOG]2.0.CO;2 PG 14 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 252UZ UT WOS:000252473500002 ER PT J AU Leshkevich, GA Nghiem, SV AF Leshkevich, George A. Nghiem, Son V. TI Satellite SAR remote sensing of Great Lakes ice cover, part 2. Ice classification and mapping SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE Synthetic Aperture Radar (SAR); Great Lakes; ice; classification; mapping; RADARSAT; ERS-2; satellite; remote sensing AB During the 1997 winter season, shipborne polarimetric backscatter measurements of Great Lakes (freshwater) ice types using the Jet propulsion Laboratory C-band scatterometer, together with surface-based ice physical characterization measurements and environmental parameters, were acquired concurrenty with Earth Resource Satellite 2 (ERS-2) and RADARSAT Synthetic Aperture Radar (SAR) data. This polarimetric data set, composed of over 20 variations of different ice types measured at incident angles from 0 degrees to 60 degrees for all polarizations, was processed to radar cross-section to establish a library of signatures (look-tip table) for different ice types. The library is used in the computer classification of calibrated satellite SAR data. Computer analysis of ERS-2 and RADARSAT ScanSAR images of Great Lakes ice cover using a supervised classification technique indicates that different ice types in the ice cover can be identified and mapped, and that wind speed and direction can have an influence on the classification of water as ice based on single frequency, single polarization data. Once satellite SAR data are classified into ice types, the ice map provides important and necessary input for environmental protection and management, ice control and ice breaking operations, and ice forecasting and modeling efforts. C1 [Leshkevich, George A.] NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. [Nghiem, Son V.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Leshkevich, GA (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. EM george.leshkevich@noaa.gov NR 38 TC 5 Z9 6 U1 1 U2 5 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2205 COMMONWEALTH BLVD, ANN ARBOR, MI 48105 USA SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PD DEC PY 2007 VL 33 IS 4 BP 736 EP 750 DI 10.3394/0380-1330(2007)33[736:SSRSOG]2.0.CO;2 PG 15 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 252UZ UT WOS:000252473500003 ER PT J AU Tian, Y Peters-Lidard, CD Choudhury, BJ Garcia, M AF Tian, Yudong Peters-Lidard, Christa D. Choudhury, Bhaskar J. Garcia, Matthew TI Multitemporal analysis of TRMM-based satellite precipitation products for land data assimilation applications SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID SPATIAL RAINFALL VARIABILITY; GLOBAL PRECIPITATION; PASSIVE-MICROWAVE; TEMPORAL RESOLUTION; RADAR RAINFALL; IMPACT; SENSITIVITY; SCALES; CMORPH; STATES AB In this study, the recent work of Gottschalck et al. and Ebert et al. is extended by assessing the suitability of two Tropical Rainfall Measuring Mission (TRMM)-based precipitation products for hydrological land data assimilation applications. The two products are NASA's gauge-corrected TRMM 3B42 Version 6 (3B42), and the satellite-only NOAA Climate Prediction Center (CPC) morphing technique (CMORPH). The two products were evaluated against ground-based rain gauge-only and gauge-corrected Doppler radar measurements. The analyses were performed at multiple time scales, ranging from annual to diurnal, for the period March 2003 through February 2006. The analyses show that at annual or seasonal time scales, TRMM 3B42 has much lower biases and RMS errors than CMORPH. CMORPH shows season-dependent biases, with overestimation in summer and underestimation in winter. This leads to 50% higher RMS errors in CMORPH's area-averaged daily precipitation than TRMM 3B42. At shorter time scales (5 days or less), CMORPH has slightly less uncertainty, and about 10%-20% higher probability of detection of rain events than TRMM 3B42. In addition, the satellite estimates detect more high-intensity events, causing a remarkable shift in precipitation spectrum. Summertime diurnal cycles in the United States are well captured by both products, although the 8-km CMORPH seems to capture more diurnal features than the 0.25 degrees CMORPH or 3B42 products. CMORPH tends to overestimate the amplitude of the diurnal cycles, particularly in the central United States. Possible causes for the discrepancies between these products are discussed. C1 [Tian, Yudong; Peters-Lidard, Christa D.; Choudhury, Bhaskar J.] NASA, Goddard Space Flight Ctr, GEST Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. [Tian, Yudong; Garcia, Matthew] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Tian, Y (reprint author), NASA, Goddard Space Flight Ctr, GEST Ctr, Hydrol Sci Branch, Mail Code 614-3, Greenbelt, MD 20771 USA. EM Yudong.Tian@nasa.gov RI Garcia, Matthew/K-9286-2013; Measurement, Global/C-4698-2015; Peters-Lidard, Christa/E-1429-2012 OI Garcia, Matthew/0000-0002-9637-4204; Peters-Lidard, Christa/0000-0003-1255-2876 NR 33 TC 136 Z9 143 U1 0 U2 14 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X J9 J HYDROMETEOROL JI J. Hydrometeorol. PD DEC PY 2007 VL 8 IS 6 BP 1165 EP 1183 DI 10.1175/2007JHM859.1 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 247QT UT WOS:000252095100001 ER PT J AU Rouault, M Illig, S Bartholomae, C Reason, CJC Bentamy, A AF Rouault, M. Illig, S. Bartholomae, C. Reason, C. J. C. Bentamy, A. TI Propagation and origin of warm anomalies in the Angola Benguela upwelling system in 2001 SO JOURNAL OF MARINE SYSTEMS LA English DT Article DE Angola Benguela upwelling system; tropical Atlantic variability; ocean atmosphere interaction ID SEA-SURFACE TEMPERATURE; TROPICAL ATLANTIC-OCEAN; EASTERN ATLANTIC; SOUTHERN-AFRICA; AIR-TEMPERATURE; SATELLITE DATA; THERMAL DOMES; FRONTAL ZONE; UPPER-LAYER; MARCH 1995 AB Warmer than average sea surface temperatures were observed by the Tropical Rainfall Mission Microwave Imager in the Angola Benguela Current system in late austral summer 2001 and persisted for about three months. These coastal anomalies extended offshore by 1 to 4 degrees longitude and were not due to local ocean atmosphere interaction or relaxation of the upwelling favorable southerly winds. Instead, they were remotely forced by ocean atmosphere interaction in the Tropical Atlantic. Satellite remote sensing and a linear ocean model suggest that relaxation of trade winds along the equator triggered Kelvin waves that crossed the basin within a month in early 2001. Westerly wind anomalies were also observed in December 2000 and January 2001 over most of the Tropical Atlantic contributing to a warm preconditioning due to an enhancement of the oceanic annual cycle. This led to abnormal sea level heights near equatorial Africa that propagated southwards along the coast towards the Angola Benguela Frontal zone. This process increased the seasonal penetration of warm and salty water of tropical origin into the Angola Benguela upwelling system. (C) 2006 Elsevier B.V All rights reserved. C1 [Rouault, M.; Reason, C. J. C.] Univ Cape Town, Dept Oceanog, ZA-7701 Rondebosch, South Africa. [Illig, S.] NASA, Jet Propuls Lab, Pasadena, CA USA. [Bartholomae, C.] Natl Marine Informat & Res Ctr, Swakopmund, Namibia. [Bentamy, A.] IFREMER, Plouzane, France. [Illig, S.] Legos, Toulouse, France. RP Rouault, M (reprint author), Univ Cape Town, Dept Oceanog, Private Bag, ZA-7701 Rondebosch, South Africa. EM rouault@ocean.uct.ac.za RI Rouault, Mathieu/A-5022-2008 OI Rouault, Mathieu/0000-0002-3207-6777 NR 59 TC 32 Z9 32 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-7963 EI 1879-1573 J9 J MARINE SYST JI J. Mar. Syst. PD DEC PY 2007 VL 68 IS 3-4 BP 473 EP 488 DI 10.1016/j.jmarsys.2006.11.010 PG 16 WC Geosciences, Multidisciplinary; Marine & Freshwater Biology; Oceanography SC Geology; Marine & Freshwater Biology; Oceanography GA 244AD UT WOS:000251837500011 ER PT J AU Toth, RA Miller, CE Devi, VM Benner, DC Brown, LR AF Toth, R. A. Miller, C. E. Devi, V. Malathy Benner, D. C. Brown, L. R. TI Air-broadened halfwidth and pressure shift coefficients of (CO2)-C-12-O-16 bands: 4750-7000 cm(-1) SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE carbon dioxide; CO2; air-broadening; near infrared; lorentz widths; pressure shift ID CONSTRAINED MULTISPECTRUM ANALYSIS; NEAR-INFRARED SPECTROSCOPY; CARBON-DIOXIDE; LINE POSITIONS; MU-M; LASER SPECTROSCOPY; SPEED DEPENDENCE; CO2; INTENSITIES; PARAMETERS AB Previously we obtained self-broadened halfwidth and self-induced shift coefficients at room temperature for 15 near infrared CO2 bands between 4750 and 7000 cm(-1) [R.A. Toth, L.R. Brown, C.E. Miller, V.M. Devi, D.C. Benner, J. Mol. Spectrosc., 239 (2006) 243-271]. The present study expands our work on the near infrared line parameters Of CO2 to include air broadening coefficients. Here we report nearly 400 air-broadened half width and air-induced pressure shift coefficients spanning I I different CO2 vibrational bands in the 4750-7000 cm(-1) region. Retrievals have been performed using Voigt line profiles over three distinct spectral intervals: (a) 47505200 cm(-1), covering the 20011 <- 00001, 20012 <- 00001, and 20013 <- 00001 Fermi Triad and three associated hot bands 21111 <- 0 110 1, 21112 <- 0 110 1, 21113 <- 01101; (b) 6100-7000 cm(-1), covering the 30011 <- 00001, 30012 <- 00001, 30013 <- 00001 and 30014 <- 00001 Fermi Tetrad; (c) near 6950 cm(-1) for the 00031 <- 0000 1 overtone band. The air-broadened halfwidth and air-induced pressure shift coefficients have been modeled with empirical expressions and compared to other measurements available in the literature. (c) 2007 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Coll William & Mary, Williamsburg, VA 23187 USA. RP Toth, RA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ratoth@jpl.nasa.gov NR 30 TC 40 Z9 39 U1 0 U2 6 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD DEC PY 2007 VL 246 IS 2 BP 133 EP 157 DI 10.1016/j.jms.2007.09.005 PG 25 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 238PV UT WOS:000251460600001 ER PT J AU Mackenzie, CL AF Mackenzie, Clyde L., Jr. TI Causes underlying the historical decline in eastern oyster (Crassostrea virginica Gmelin, 1791) landings SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article DE oyster; Crassostrea virginica; East Coast; Gulf Coast; Canada; landings; consumer demand; pathogens; economic depressions; bed damage ID DELAWARE BAY; CHESAPEAKE BAY; NELSONI MSX; RESISTANCE; MORTALITY; PROGRAM; ISLAND AB Landings of eastern oysters (Crassostrea virginica) along the United States East Coast (mainly Rhode Island through South Carolina) increased to nearly 27 million bushels by 1890s, but they then declined by, nearly 60% to 11.5 million bushels by 1940 and by almost 99% to 0.35 million bushels by 2004. Though overharvesting usually has been cited as the primary factor for the decline in landings from 1890 to 1940, the principal causes were: (1) a fall in demand for oysters, because consumers became aware that oysters could contain pathogens and competition from other foods increased in markets; (2) three economic depressions; and (3) biological and physical damage to the oysters and their beds (predation, siltation, severe storms, channel dredging, and harvesting by dredges). As a consequence of a huge decline in oyster landings in Delaware and Chesapeake Bays during and after the 1960s because of high oyster mortalities caused by the diseases MSX and Dermo, space became available in the United States national oyster market. The oyster industries of Prince Edward Island, Long Island Sound (Connecticut and New York), and the United States Gulf Coast took advantage of this and increased their production. C1 NOAA, Natl Marine Fisheries Serv, James J Howard Marine Sci Lab, NE Fisheries Sci Ctr, Highlands, NJ 07732 USA. RP Mackenzie, CL (reprint author), NOAA, Natl Marine Fisheries Serv, James J Howard Marine Sci Lab, NE Fisheries Sci Ctr, 74 Magruder Rd, Highlands, NJ 07732 USA. EM clyde.mackenzie@noaa.gov NR 78 TC 21 Z9 22 U1 6 U2 37 PU NATL SHELLFISHERIES ASSOC PI GROTON PA C/O DR. SANDRA E. SHUMWAY, UNIV CONNECTICUT, 1080 SHENNECOSSETT RD, GROTON, CT 06340 USA SN 0730-8000 EI 1943-6319 J9 J SHELLFISH RES JI J. Shellfish Res. PD DEC PY 2007 VL 26 IS 4 BP 927 EP 938 DI 10.2983/0730-8000(2007)26[927:CUTHDI]2.0.CO;2 PG 12 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 250US UT WOS:000252327300006 ER PT J AU Jones, SM AF Jones, Steven M. TI A method for producing gradient density aerogel SO JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY LA English DT Article DE aerogel; gradient density; sol-gel ID STARDUST; CAPTURE; IMPACT AB The Stardust Mission used gradient density aerogel as the hypervelocity particle capture medium in both the cometary and interstellar collection grids. The development and production of these materials was performed exclusively for this mission as a means of improving the efficiency of the collection process. The density of an aerogel can be dictated by controlling the ratio of the condensable silica to that of the solvent used in the aerogel precursor solution. A density gradient was established by gradually mixing the precursor solution for low density aerogel into the precursor solution for high density aerogel and continuously pumping the resultant mixture into a mold. The aerogel designed for the capture of cometary particles had a density gradient ranging from 10 mg/cm(3) to 50 mg/cm(3) across the 3 cm profile of each block. Whereas those designed for the capture of interstellar grains had a gradient ranging from 10 mg/cm(3) to 20 mg/cm(3) across a 1 cm profile. Since various physical properties, e.g., refractive index, thermal conductivity, acoustic impedance, dielectric constant, are correlated to the density, they also vary with the density. This method of establishing a density gradient in aerogel can be used to produce other material gradients, e.g., gradient oxide, gradient dopant, in any sol-gel based material. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Jones, SM (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. EM Steven.M.Jones@jpl.nasa.gov NR 11 TC 31 Z9 37 U1 4 U2 25 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0928-0707 J9 J SOL-GEL SCI TECHN JI J. Sol-Gel Sci. Technol. PD DEC PY 2007 VL 44 IS 3 BP 255 EP 258 DI 10.1007/s10971-007-1618-7 PG 4 WC Materials Science, Ceramics SC Materials Science GA 226ZH UT WOS:000250626500012 ER PT J AU Zeng, X Tao, WK Zhang, MH Peters-Lidard, C Lang, S Simpson, J Kumar, S Xie, SC Eastman, JL Shie, CL Geiger, JV AF Zeng, Xiping Tao, Wei-Kuo Zhang, Minghua Peters-Lidard, Christa Lang, Stephen Simpson, Joanne Kumar, Sujay Xie, Shaocheng Eastman, Joseph L. Shie, Chung-Lin Geiger, James V. TI Evaluating clouds in long-term cloud-resolving model Simulations with observational data SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GENERAL-CIRCULATION MODELS; DEEP TROPICAL CLOUDS; RADIATION INTERACTION; SURFACE PROCESSES; TOGA COARE; BULK PARAMETERIZATION; NUMERICAL-SIMULATION; CUMULUS CLOUDS; SUBCLOUD-LAYER; GRAVITY-WAVES AB Two 20-day, continental midlatitude cases are simulated with a three-dimensional (313) cloud-resolving model (CRM) and are compared to Atmospheric Radiation Measurement Program (ARM) data. Surface fluxes from ARM ground stations and a land data assimilation system are used to drive the CRM. This modeling evaluation shows that the model simulates precipitation well but overpredicts clouds, especially in the upper troposphere. The evaluation also shows that the ARM surface fluxes can have noticeable errors in summertime. Theoretical analysis reveals that buoyancy damping is sensitive to spatial smoothers in two-dimensional (2D) CRMs, but not in 3D ones. With this theoretical analysis and the ARM cloud observations as background, 2D and 3D simulations are compared, showing that the 2D CRM has not only rapid fluctuations in surface precipitation but also spurious dehumidification (or a decrease in cloud amount). The present study suggests that the rapid precipitation fluctuation and spurious dehumidification be attributed to the sensitivity of buoyancy damping to dimensionality. C1 [Zeng, Xiping; Tao, Wei-Kuo; Lang, Stephen; Simpson, Joanne; Shie, Chung-Lin] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. [Zeng, Xiping; Kumar, Sujay; Eastman, Joseph L.; Shie, Chung-Lin] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. [Zhang, Minghua] SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. [Peters-Lidard, Christa; Kumar, Sujay; Eastman, Joseph L.; Geiger, James V.] NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD USA. [Peters-Lidard, Christa; Kumar, Sujay; Eastman, Joseph L.; Geiger, James V.] Syst Sci & Applicat Inc, Lanham, MD USA. [Xie, Shaocheng] Lawrence Livermore Natl Lab, Div Atmospher Sci, Livermore, CA USA. RP Zeng, X (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Mail Code 613-1, Greenbelt, MD 20771 USA. EM zeng@agnes.gsfc.nasa.gov RI Peters-Lidard, Christa/E-1429-2012; Xie, Shaocheng/D-2207-2013; Kumar, Sujay/B-8142-2015 OI Peters-Lidard, Christa/0000-0003-1255-2876; Xie, Shaocheng/0000-0001-8931-5145; NR 73 TC 38 Z9 38 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC PY 2007 VL 64 IS 12 BP 4153 EP 4177 DI 10.1175/2007JAS2170.1 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 244WQ UT WOS:000251896400001 ER PT J AU Zhou, YP Tao, WK Hou, AY Olson, WS Shie, CL Lau, KM Chou, MD Lin, X Grecu, M AF Zhou, Y. P. Tao, W. -K. Hou, A. Y. Olson, W. S. Shie, C.-L. Lau, K. -M. Chou, M. -D. Lin, X. Grecu, M. TI Use of high-resolution satellite observations to evaluate cloud and precipitation statistics from cloud-resolving model simulations. Part I: South China Sea Monsoon Experiment SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID MEASURING MISSION TRMM; MESOSCALE CONVECTIVE SYSTEMS; TROPICAL CUMULUS CLOUDS; LONG-TERM BEHAVIOR; TOGA COARE; BULK PARAMETERIZATION; SURFACE PROCESSES; SQUALL LINES; PHASE-III; ENVIRONMENTAL-CONDITIONS AB Cloud and precipitation simulated using the three-dimensional (313) Goddard Cumulus Ensemble (GCE) model are compared to Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and Precipitation Radar (PR) rainfall measurements and Clouds and the Earth's Radiant Energy System (CERES) single scanner footprint (SSF) radiation and cloud retrievals. Both the model simulation and retrieved parameters are based upon observations made during the South China Sea Monsoon Experiment (SCSMEX) field campaign. The model-simulated cloud and rain systems are evaluated by systematically examining important parameters such as the surface rain rate, convective/stratiform percentage, rain profiles, cloud properties, and precipitation efficiency. It is demonstrated that the GCE model is capable of simulating major convective system development and reproduces the total surface rainfall amount as compared to rainfall estimated from the SCSMEX sounding network. The model yields a slightly higher total convective rain/stratiform rain ratio than the TMI and PR observations. The GCE rainfall spectrum exhibits a greater contribution from heavy rains than those estimated from PR or TMI observations. In addition, the GCE simulation produces much greater amounts of snow and graupel than the TRMM retrievals. The model's precipitation efficiency of convective rain is close to the observations, but the precipitation efficiency of stratiform rain is much lower than the observations because of large amounts of slowly falling simulated snow and graupel. Compared to observations, the GCE produces more compact areas of intense convection and less anvil cloud, which are consistent with a smaller total cloud fraction and larger domain-averaged outgoing longwave radiation. C1 [Tao, W. -K.; Hou, A. Y.; Lau, K. -M.; Lin, X.; Grecu, M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. [Zhou, Y. P.; Shie, C.-L.; Lin, X.; Grecu, M.] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. [Olson, W. S.] Univ Maryland, Joint Ctr Earth Syst Technol, Baltimore, MD 21201 USA. [Chou, M. -D.] Natl Taiwan Univ, Taipei 10764, Taiwan. RP Zhou, YP (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 613-2, Greenbelt, MD USA. EM yaping.zhou-1@nasa.gov RI Hou, Arthur/D-8578-2012; Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 80 TC 31 Z9 32 U1 2 U2 11 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC PY 2007 VL 64 IS 12 BP 4309 EP 4329 DI 10.1175/2007JAS2281.1 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 244WQ UT WOS:000251896400008 ER PT J AU Randel, WJ Park, MJ Wu, F Livesey, N AF Randel, William J. Park, Mijeong Wu, Fei Livesey, Nathaniel TI A large annual cycle in ozone above the tropical tropopause linked to the Brewer-Dobson circulation SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID LOWER STRATOSPHERE; TEMPERATURES; CLIMATOLOGY; VARIABILITY; OCCULTATION; SATELLITE; TRANSPORT AB Near-equatorial ozone observations from balloon and satellite measurements reveal a large annual cycle in ozone above the tropical tropopause. The relative amplitude of the annual cycle is large in a narrow vertical layer between similar to 16 and 19 km, with approximately a factor of 2 change in ozone between the minimum (during NH winter) and maximum (during NH summer). The annual cycle in ozone occurs over the same altitude region, and is approximately in phase with the well-known annual variation in tropical temperature. This study shows that the large annual variation in ozone occurs primarily because of variations in vertical transport associated with mean upwelling in the lower stratosphere (the Brewer-Dobson circulation); the maximum relative amplitude peak in the lower stratosphere is collocated with the strongest background vertical gradients in ozone. A similar large seasonal cycle is observed in carbon monoxide (CO) above the tropical tropopause, which is approximately out of phase with ozone (associated with an oppositely signed vertical gradient). The observed ozone and CO variations can be used to constrain estimates of the seasonal cycle in tropical upwelling. C1 [Randel, William J.; Park, Mijeong; Wu, Fei] Natl Ctr Atmospher Res, Boulder, CO 80307 USA. [Livesey, Nathaniel] CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Randel, WJ (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM randel@ucar.edu RI Randel, William/K-3267-2016 OI Randel, William/0000-0002-5999-7162 NR 28 TC 73 Z9 73 U1 2 U2 19 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC PY 2007 VL 64 IS 12 BP 4479 EP 4488 DI 10.1175/2007JAS2409.1 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 244WQ UT WOS:000251896400019 ER PT J AU Kupinski, MA Watson, AB Siewerdsen, JH Myers, KJ Eckstein, M AF Kupinski, Matthew A. Watson, Andrew B. Siewerdsen, Jeffrey H. Myers, Kyle J. Eckstein, Miguel TI Image quality - Introduction SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Editorial Material C1 [Kupinski, Matthew A.] Univ Arizona, Coll Opt sci, Tucson, AZ 85721 USA. [Kupinski, Matthew A.] Univ Arizona, Dept Radiol, Tucson, AZ 85721 USA. [Watson, Andrew B.] NASA, Ames Res Ctr, Vis Grp, Moffett Field, CA 94035 USA. [Siewerdsen, Jeffrey H.] Univ Toronto, Div Biophys & Bioimaging, Toronto, ON M5G 2M9, Canada. [Myers, Kyle J.] US FDA, NIBIB CDRH Lab Assessment Med Imaging Syst, Rockville, MD 20857 USA. [Eckstein, Miguel] Univ Calif Santa Barbara, Dept Psychol, Santa Barbara, CA 93106 USA. RP Kupinski, MA (reprint author), Univ Arizona, Coll Opt sci, Tucson, AZ 85721 USA. EM mkupinski@optics.arizona.edu; andrew.b.watson@nasa.gov; jsiewerd@uhnres.utoronto.ca; kyle.myers@fda.hhs.gov; eckstein@psych.ucsb.edu NR 0 TC 0 Z9 0 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1084-7529 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD DEC PY 2007 VL 24 IS 12 PG 1 WC Optics SC Optics GA 248BP UT WOS:000252126600001 ER PT J AU Savchenkov, AA Matsko, AB Ilchenko, VS Yu, N Maleki, L AF Savchenkov, Anatoliy A. Matsko, Andrey B. Ilchenko, Vladimir S. Yu, Nan Maleki, Lute TI Whispering-gallery-mode resonators as frequency references. II. Stabilization SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID NEGATIVE THERMAL-EXPANSION; OPTICAL RESONATORS; BARIUM FLUORIDE; HEAT-CAPACITY; DIODE-LASER; TEMPERATURE-DEPENDENCE; SYNTHETIC SAPPHIRE; MAGNESIUM FLUORIDE; ELASTIC-CONSTANTS; CALCIUM-FLUORIDE AB We show theoretically that the absolute frequency stability of a solid-state millimeter-scale whispering gallery mode resonator can reach one part per 10(14) per 1 s integration time if proper crystalline material as well as proper stabilization technique is selected. Both the fluctuations of the resonator temperature and the fluctuations of the temperature in the mode volume can be measured with the sensitivity better than the fundamental thermodynamic limit and actively compensated. (C) 2007 Optical Society of America. C1 [Savchenkov, Anatoliy A.; Matsko, Andrey B.; Ilchenko, Vladimir S.; Yu, Nan; Maleki, Lute] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Matsko, AB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Andrey.Matsko@jpl.nasa.gov RI Matsko, Andrey/A-1272-2007 NR 70 TC 61 Z9 61 U1 4 U2 21 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD DEC PY 2007 VL 24 IS 12 BP 2988 EP 2997 DI 10.1364/JOSAB.24.002988 PG 10 WC Optics SC Optics GA 248BN UT WOS:000252126400009 ER PT J AU Jalbout, AF AF Jalbout, Abraham F. TI On the evaluation of the rigorous electrostatic potential/atomic energy relationship SO JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY LA English DT Article DE electrostatic potential; rigorous expressions; energies; DFT ID THOMAS-FERMI; DENSITY; MOLECULES; ATOMS; APPROXIMATION; FORMULAS; ELECTRONEGATIVITY; EXCHANGE; SYSTEMS; LENGTH AB A series of atomic energy formulas that relate atomic energies to the electrostatic potentials V-0 at nuclei are obtained by a series of polynomial and series fits of V0 versus nuclear charge (Z). Density functional and Hartree-Fock V-0 are used for a series of fits that involve an isoelectronic series of anions, cations, and neutral ground state atoms to approximate atomic energies. Comparisons to the exact energies were performed in order to demonstrate the efficacy of the rigorous expressions. C1 [Jalbout, Abraham F.] Univ Nacl Autonoma Mexico, Inst Quim, Mexico City 04510, DF, Mexico. [Jalbout, Abraham F.] Univ Arizona, NASA, Astrobiol Inst, Tucson, AZ 85721 USA. [Jalbout, Abraham F.] Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. RP Jalbout, AF (reprint author), Univ Nacl Autonoma Mexico, Inst Quim, Mexico City 04510, DF, Mexico. EM ajalbout@u.arizona.edu NR 39 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0219-6336 EI 1793-6888 J9 J THEOR COMPUT CHEM JI J. Theor. Comput. Chem. PD DEC PY 2007 VL 6 IS 4 BP 761 EP 788 DI 10.1142/S0219633607003386 PG 28 WC Chemistry, Multidisciplinary SC Chemistry GA 254VF UT WOS:000252615400009 ER PT J AU Kharkovsky, S Zoughi, R Hepburn, E AF Kharkovsky, S. Zoughi, R. Hepburn, El. TI High resolution millimeter wave imaging of space shuffle external fuel tank spray-on foam insulation SO MATERIALS EVALUATION LA English DT Article DE millimeter waves; high resolution imaging; space shuttle; insulating foam; SOFT; focusing lens; nondestructive testing; discontinuities; voids ID MICROWAVE AB The Space Shuttle Columbia's catastrophic structural failure was caused by a dislodged piece of spray-on foam insulation (SOFT) from the external fuel tank. Separation of SOFT pieces may be caused by the presence within the foam of anomalies such as voids, delaminations and disbonds. These unwanted discontinuities may occur during the spraying of the foam onto the external tank or may be due to post-spray damage. High spatial resolution millimeter wave nondestructive testing and imaging techniques have shown great potential and overall system utility for evaluating internal SOFI structures. This paper presents the basic design of a 150 GHz imaging reflectometer system and discusses the results of a critical investigation of the capabilities of this system that examined a SOFI panel with subtle embedded delaminations and voids without sharp boundaries, and another special panel possessing unknown natural discontinuities (the result of intentional manufacturing processes). Finally, the information obtained from the millimeter wave images was correlated with information obtained from post-imaging dissection of the panel. It was shown that 91% of the discontinuities (such as extended and localized voids and delaminations) were successfully identified using this millimeter wave imaging system. C1 Univ Missouri, Dept Elect & Comp Engn, Appl Micowave Nondestruct Tesing Lab, Rolla, MO 65409 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Kharkovsky, S (reprint author), Univ Missouri, Dept Elect & Comp Engn, Appl Micowave Nondestruct Tesing Lab, Rolla, MO 65409 USA. EM sergiy@umr.edu; zoughir@umr.edu; frank.l.hepbum@nasa.gov NR 24 TC 4 Z9 4 U1 0 U2 0 PU AMER SOC NONDESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD DEC PY 2007 VL 65 IS 12 BP 1220 EP 1229 PG 10 WC Materials Science, Characterization & Testing SC Materials Science GA 237FL UT WOS:000251359500005 ER PT J AU Ashbourn, SFM Elsila, JE Dworkin, JP Bernstein, MP Sandford, SA Allamandola, LJ AF Ashbourn, Samantha F. M. Elsila, Jamie E. Dworkin, Jason P. Bernstein, Max P. Sandford, Scott A. Allamandola, Louis J. TI Ultraviolet photolysis of anthracene in H(2)O interstellar ice analogs: Potential connection to meteoritic organics SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; INTERPLANETARY DUST PARTICLES; MURCHISON METEORITE; CARBONACEOUS CHONDRITES; DEUTERIUM ENRICHMENT; ASTROPHYSICAL ICES; VACUUM-ULTRAVIOLET; MASS-SPECTROMETRY; RADIATION-FIELD; UV-RADIATION AB The polycyclic aromatic hydrocarbon (PAH) anthracene was oxidized by exposure to ultraviolet (UV) radiation in H(2)O ice under simulated astrophysical conditions, forming several anthracene ketones (9-anthrone, 1,4-anthraquinone, and 9, 10-anthraquinone) and alcohols (1-anthrol and 2-anthrol). Two of the ketones produced have been detected in the Murchison meteorite but, to our knowledge, there has been no search for the alcohols or other oxidized anthracenes in meteorites. These results seem consistent with the possibility that interstellar ice photochemistry could have influenced the inventory of aromatics in meteorites. Since quinones are also fundamental to biochemistry, their formation in space and delivery to planets is relevant to studies relating to the habitability of planets and the evolution of life. C1 [Ashbourn, Samantha F. M.; Elsila, Jamie E.; Bernstein, Max P.; Sandford, Scott A.; Allamandola, Louis J.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Dworkin, Jason P.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Elsila, Jamie E.] SETI Inst, Moffett Field, CA 94043 USA. [Ashbourn, Samantha F. M.] SRI Int, Menlo Pk, CA 94025 USA. RP Sandford, SA (reprint author), NASA, Ames Res Ctr, Mail Stop 245-6, Moffett Field, CA 94035 USA. RI Elsila, Jamie/C-9952-2012; Dworkin, Jason/C-9417-2012 OI Dworkin, Jason/0000-0002-3961-8997 NR 56 TC 22 Z9 22 U1 2 U2 12 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD DEC PY 2007 VL 42 IS 12 BP 2035 EP 2041 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 287UC UT WOS:000254941000001 ER PT J AU Martins, Z Alexander, CMO Orzechowska, GE Fogel, ML Ehrenfreund, P AF Martins, Z. Alexander, C. M. O'D. Orzechowska, G. E. Fogel, M. L. Ehrenfreund, P. TI Indigenous amino acids in primitive CR meteorites SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID CARBONACEOUS CHONDRITE; ORGANIC-MATTER; ANTARCTIC MICROMETEORITES; LIQUID-CHROMATOGRAPHY; MASS SPECTROMETRY; SEARCH; MURCHISON; ISOTOPE AB CR chondrites are among the most primitive meteorites. In this paper, we report the first measurements of amino acids in Antarctic CR meteorites. Three CRs, Elephant Moraine (EET) 92042, Graves Nunataks (GRA) 95229, and Grosvenor Mountains (GRO) 95577, were analyzed for their amino acid content using high-performance liquid chromatography with UV fluorescence detection (HPLC-FD) and gas chromatography-mass spectrometry (GC-MS). Our data show that EET 92042 and GRA 95229 are the most amino acid-rich chondrites ever analyzed, with total amino acid concentrations ranging from 180 ppm to 249 ppm. The most abundant amino acids present in the EET 92042 and GRA 95229 meteorites are the alpha-amino acids glycine, isovaline, alpha-aminoisobutyric acid (alpha-AIB), and alanine, with delta(13)C values ranging from +31.6%. to +50.5%.. The carbon isotope results together with racemic enantiomeric ratios determined for most amino acids strongly indicate an extraterrestrial origin for these compounds. Compared to Elephant Moraine (EET) 92042 and GRA 95229, the more aqueously altered GRO 95577 is depleted in amino acids. In both CRs and CMs, the absolute amino acid abundances appear to be related to the degree of aqueous alteration in their parent bodies. In addition, the relative abundances of C1 [Alexander, C. M. O'D.] Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. [Martins, Z.; Ehrenfreund, P.] Leiden Inst Chem, Astrobiol Lab, NL-2300 RA Leiden, Netherlands. [Orzechowska, G. E.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Fogel, M. L.] Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. RP Martins, Z (reprint author), Univ London Imperial Coll Sci Technol & Med, Dept Earth Sci & Engn, London SW7 2AZ, England. EM z.martins@imperial.ac.uk RI Alexander, Conel/N-7533-2013; Fogel, Marilyn/M-2395-2015; Martins, Zita/H-4860-2015 OI Alexander, Conel/0000-0002-8558-1427; Fogel, Marilyn/0000-0002-1176-3818; Martins, Zita/0000-0002-5420-1081 NR 43 TC 75 Z9 77 U1 5 U2 30 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD DEC PY 2007 VL 42 IS 12 BP 2125 EP 2136 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 287UC UT WOS:000254941000009 ER PT J AU Abell, PA Vilas, F Jarvis, KS Gaffey, MJ Kelley, MS AF Abell, Paul A. Vilas, Faith Jarvis, Kandy S. Gaffey, Michael J. Kelley, Michael S. TI Mineralogical composition of (25143) Itokawa 1998 SF36 from visible and near-infrared reflectance spectroscopy: Evidence for partial melting SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID C MISSION TARGET; ASTEROID-25143 ITOKAWA; PHYSICAL-CHARACTERISTICS; CCD PHOTOMETRY; SOLAR-SYSTEM; HAYABUSA; SPECTRA; METEORITES; ORIGIN AB In March 2001, asteroid (25143) Itokawa, the target of the Japanese Hayabusa spacecraft mission, was in a favorable viewing geometry for ground-based telescopic study. Visible/near-infrared (VNIR) spectra (similar to 0.48 to 0.9 mu m) obtained on March 24, 26, and 27 UT, and near-infrared (NIR) spectra (similar to 0.75 to 2.5 mu m) obtained on March 10, 11, 12, 23, and 24 UT collectively show absorption features centered near 1.0 and 2.0 mu m, which are indicative of olivine and pyroxene. Analyses of these absorption features indicate an abundance ratio of olivine to pyroxene of approximately 75:25 +/- 5, respectively, with no significant variation in the relative abundance of these minerals across its surface on a regional scale. The band center positions indicate that the mean pyroxene chemistry is similar to Wo(14) (+/- 5)Fs(43) (+/-) (5). There appear to be at least two pyroxene components: primarily a low-Ca orthopyroxene accompanied by a spectrally significant (similar to 15-20%) high Fe-rich pigeonite phase. The mean pyroxene composition is significantly more Fe-rich than the Fs(14-26) range found in ordinary chondrites. These pyroxene compositions are suggestive of phases crystallized from partial melts. This would indicate that the parent body of (25143) Itokawa reached temperatures sufficient to initiate partial melting (similar to 1050 to 1250 degrees C), but that it did not attain the degree of melting required for significant melt mobilization and efficient segregation of the basaltic melt component from the unmelted residual olivine portion. Itokawa's spectral band parameters place it near the S(III)/S(IV) boundary, but within the S(III) taxonomic field. In meteoritic nomenclature, Itokawa would be most analogous to an olivine-rich primitive achondrite. Alternatively, if the high FS value is not related to partial melting, then Itokawa could also represent a rare atypical LL chondrite, or a previously unsampled oxidized Fe-rich chondritic-like assemblage. C1 [Abell, Paul A.; Vilas, Faith; Jarvis, Kandy S.; Kelley, Michael S.] NASA, Johnson Space Ctr, Planetary Astron Grp, Houston, TX 77085 USA. [Jarvis, Kandy S.] ESC Grp, Jacobs Sverdrup, Houston, TX 77085 USA. [Gaffey, Michael J.] Univ N Dakota, Dept Space Studies, Grand Forks, ND 58202 USA. RP Abell, PA (reprint author), NASA, Johnson Space Ctr, Planetary Astron Grp, Mail Code KR, Houston, TX 77085 USA. EM paul.a.abell@jsc.nasa.gov NR 39 TC 15 Z9 15 U1 0 U2 2 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD DEC PY 2007 VL 42 IS 12 BP 2165 EP 2177 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 287UC UT WOS:000254941000012 ER PT J AU Larson, KM Ashby, N Hackman, C Bertiger, W AF Larson, Kristine M. Ashby, Neil Hackman, Christine Bertiger, Willy TI An assessment of relativistic effects for low Earth orbiters: the GRACE satellites SO METROLOGIA LA English DT Article ID GPS CARRIER-PHASE; TIME-TRANSFER AB The GRACE mission consists of two identical satellites orbiting the Earth at an altitude of similar to 500 km. Dual-frequency carrier-phase Global Positioning System (GPS) receivers are flying on both satellites. They are used for precise orbit determination and to time-tag the K-band ranging system used to measure changes in the distances between the two satellites. The satellites are also flying ultra-stable oscillators (USOs) to achieve the mission's need for short-term (< 1 s) oscillator stability. Because of the high quality of both the GPS receivers and the oscillators, relativistic effects in the GRACE GPS data can be examined. An expression is developed for relativistic effects that explicitly includes the effects of the Earth's oblateness (J(2)). Use of this expression significantly reduces the twice per orbital period energy in the GRACE clock solutions, indicating that the effect of J2 can be significant and should be modeled for satellite clocks in low Earth orbit. After relativistic effects have been removed, both GRACE USOs show large (2 ns to 3 ns) once per orbital period signatures that correlate with voltage variations on the spacecraft. C1 [Larson, Kristine M.] Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA. [Ashby, Neil] NIST, Div Time & Frequency, Boulder, CO USA. [Hackman, Christine] USN Observ, Earth Orientat Dept, Washington, DC 20392 USA. [Bertiger, Willy] Jet Prop Lab, Radiometr Tracking Grp, Pasadena, CA USA. RP Larson, KM (reprint author), Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA. EM kristinem.larson@gmail.com NR 21 TC 12 Z9 12 U1 2 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0026-1394 J9 METROLOGIA JI Metrologia PD DEC PY 2007 VL 44 IS 6 BP 484 EP 490 DI 10.1088/0026-1394/44/6/007 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 252UL UT WOS:000252472000014 ER PT J AU Greenhall, CA AF Greenhall, Charles A. TI A Kalman filter clock ensemble algorithm that admits measurement noise: corrections and update SO METROLOGIA LA English DT Article ID MODEL; ALLAN AB This note rectifies oversights and errors in the author's recent paper about a clock ensemble algorithm based on a modified Kalman filter. It is shown by simulation and theory that initial frequency state errors can cause the corrected clocks to diverge linearly with time. Two statements about the Brown ensemble algorithm are corrected, and results of that algorithm are compared with those of the author's algorithm for a simulated three-clock ensemble. C1 [Greenhall, Charles A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Greenhall, CA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 298, Pasadena, CA 91109 USA. EM cgreenhall@jpl.nasa.gov NR 9 TC 6 Z9 6 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0026-1394 J9 METROLOGIA JI Metrologia PD DEC PY 2007 VL 44 IS 6 BP 491 EP 494 DI 10.1088/0026-1394/44/6/008 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 252UL UT WOS:000252472000015 ER PT J AU Yang, Y Gupta, MC Dudley, KL AF Yang, Y. Gupta, M. C. Dudley, K. L. TI Studies on electromagnetic interference shielding characteristics of metal nanoparticle- and carbon nanostructure-filled polymer composites in the Ku-band frequency SO MICRO & NANO LETTERS LA English DT Article ID INTRINSICALLY CONDUCTING POLYMERS; MECHANICAL-PROPERTIES; NANOTUBES; POLYANILINE; NANOCOMPOSITES; FIBERS; BLENDS; FILMS AB The dispersion behaviour and electromagnetic interference (EMI) shielding properties were investigated for metal nanoparticle- and carbon nanostructure-filled polymer composites. It was observed that carbon nanostructure-polymer composites exhibited a much higher shielding performance than Ag nanoparticle-polymer composites at the same filler loading. The results also showed that Ag nanoparticle-polymer composites could exhibit an ideal shielding performance only with a very high Ag loading ( >30 wt%). The experimental data exhibited that the shielding effectiveness of the polymer composite containing 5 wt% carbon nanotubes could reach more than 20 dB in the measured frequency region, indicating such composites can be applied to the practical EMI shielding materials. In addition, some possible approaches to further improve the shielding performance of carbon nanotube-polymer composites were proposed and discussed. C1 [Yang, Y.; Gupta, M. C.] Univ Virginia, Charles L Brown Dept Elect & Comp Engn, Charlottesville, VA 22904 USA. [Dudley, K. L.] NASA, Langley Res Ctr, Electromagnet & Sensors Res Branch, Hampton, VA 23681 USA. RP Yang, Y (reprint author), Univ Virginia, Charles L Brown Dept Elect & Comp Engn, Charlottesville, VA 22904 USA. EM yonglaiyang@hotmail.com NR 30 TC 19 Z9 19 U1 0 U2 13 PU INST ENGINEERING TECHNOLOGY-IET PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 1750-0443 J9 MICRO NANO LETT JI Micro Nano Lett. PD DEC PY 2007 VL 2 IS 4 BP 85 EP 89 DI 10.1049/mnl:20070042 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Science & Technology - Other Topics; Materials Science GA 256AB UT WOS:000252698900002 ER PT J AU McBride, VA Coe, MJ Bird, AJ Dean, AJ Hill, AB McGowan, KE Schurch, MPE Udalski, A Soszynski, I Finger, M Wilson, CA Corbet, RHD Negueruela, I AF McBride, V. A. Coe, M. J. Bird, A. J. Dean, A. J. Hill, A. B. McGowan, K. E. Schurch, M. P. E. Udalski, A. Soszynski, I. Finger, M. Wilson, C. A. Corbet, R. H. D. Negueruela, I. TI INTEGRAL observations of the Small Magellanic Cloud SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : neutron; X-rays : binaries; X-rays : individual : SMC X-1 ID BE/X-RAY BINARIES; SMC X-1; SPACED DATA; ACCRETION; ABUNDANCES; EMISSION; CATALOG; SMC-X-1; PERIOD; STARS AB The first INTEGRAL observations of the Small Magellanic Cloud (SMC) (carried out in 2003) are reported in which two sources are clearly detected. The first source, SMC X-1, shows a hard X-ray eclipse and measurements of its pulse period indicate a continuation of the long-term spin-up now covering approximately 30 years. The second source is likely to be a high-mass X-ray binary, and shows a potential periodicity of 6.8 s in the Imager on Board INTEGRAL Satellite lightcurve. An exact X-ray or optical counterpart cannot be designated, but a number of proposed counterparts are discussed. One of these possible counterparts shows a strong coherent optical modulation at similar to 2.7 d, which, together with the measured hard X-ray pulse period, would lead to this INTEGRAL source being classified as the fourth known high-mass Roche lobe overflow system. C1 Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. Univ Warsaw Observ, PL-00478 Warsaw, Poland. NASA, MSFC, Huntsville, AL 35812 USA. NASA, GSFC, USRA, Greenbelt, MD 20771 USA. Univ Alicante, Escuela Politecn Super, Dept Fis Ingn Sistemas & Teora Seal, E-03080 Alicante, Spain. RP McBride, VA (reprint author), Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. RI Negueruela, Ignacio/L-5483-2014; OI Negueruela, Ignacio/0000-0003-1952-3680; Hill, Adam/0000-0003-3470-4834 NR 29 TC 6 Z9 6 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD DEC 1 PY 2007 VL 382 IS 2 BP 743 EP 749 DI 10.1111/j.1365-2966.2007.12423.x PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235AH UT WOS:000251205400019 ER PT J AU Russell, GL AF Russell, Gary L. TI Step-mountain technique applied to an atmospheric C-grid model, or how to improve precipitation near mountains SO MONTHLY WEATHER REVIEW LA English DT Article ID ENERGY CONSERVING SCHEME; SHALLOW-WATER EQUATIONS; GLOBAL PRECIPITATION; POTENTIAL ENSTROPHY; VARIABILITY; CLIMATOLOGY; COORDINATE; ADVECTION AB Starting with Arakawa and Lamb's second-order C-grid scheme, this paper describes the modifications made to the dynamics to create a C-grid atmospheric model with a variable number of cells for each vertical column. Where mountains exist, grid cells are discarded at the bottom of the column so that the mass per square meter of retained cells is more nearly equal to that of horizontally adjacent cells. This leads to the following chain of causes and effects: decreased mass variations reduce the numerically induced alternating patterns in the horizontal velocity components, which reduce erroneous vertical mass fluxes, which reduce erroneous precipitation. In addition, horizontal flows above mountains are smoother, the Ferrel cell is stronger, and the polar cell is better organized. The C-grid performs geostrophic adjustment best among the gridpoint schemes, being the most sensitive to condensation-released heating perturbations. It also overreacts more egregiously to numerical errors, particularly with respect to the vertical mass flux, and consequently is often not used. Mesinger et al. applied the step-mountain (eta coordinate) technique to an E-grid scheme with excellent results. Its application to the C-grid reduces numerical errors in the vertical mass flux resulting in improvements in precipitation and other quantities. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Russell, GL (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM gary.l.russell@nasa.gov NR 22 TC 8 Z9 8 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD DEC PY 2007 VL 135 IS 12 BP 4060 EP 4076 DI 10.1175/2007MWR2048.1 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 245BC UT WOS:000251908400010 ER PT J AU Capadona, JR Van Den Berg, O Capadona, LA Schroeter, M Rowan, SJ Tyler, DJ Weder, C AF Capadona, Jeffrey R. Van Den Berg, Otto Capadona, Lynn A. Schroeter, Michael Rowan, Stuart J. Tyler, Dustin J. Weder, Christoph TI A versatile approach for the processing of polymer nanocomposites with self-assembled nanofibre templates SO NATURE NANOTECHNOLOGY LA English DT Article ID TUNICATE CELLULOSE WHISKERS; MECHANICAL-PROPERTIES; COMPOSITES; POLYSTYRENE; MEMBRANES; POLYPROPYLENE; DISPERSION AB The incorporation of nanoparticles into polymers is a design approach that is used in many areas of materials science. The concept is attractive because it enables the creation of materials with new or improved properties by mixing multiple constituents and exploiting synergistic effects. One important technological thrust is the development of structural materials with improved mechanical and thermal characteristics. Equally intriguing is the possibility to design functional materials with unique optical or electronic properties, catalytic activity or selective permeation. The broad technological exploitation of polymer nanocomposites is, however, stifled by the lack of effective methods to control nanoparticle dispersion. We report a simple and versatile process for the formation of homogeneous polymer/nanofibre composites. The approach is based on the formation of a three-dimensional template of well-individualized nanofibres, which is filled with any polymer of choice. We demonstrate that this template approach is broadly applicable and allows for the fabrication of otherwise inaccessible nanocomposites of immiscible components. C1 Case Western Reserve Univ, Dept Macromol Sci & Engn, Cleveland, OH 44106 USA. Louis Stokes Cleveland DVA Med Ctr, Cleveland, OH 44106 USA. Case Western Reserve Univ, Dept Biomed Engn, Cleveland, OH 44106 USA. NASA, Glenn Res Ctr, Polymer Mat Branch, Cleveland, OH 44135 USA. GKSS Res Ctr Geesthacht GmbH, Polymer Res Inst, D-14513 Teltow, Germany. Case Western Reserve Univ, Dept Chem, Cleveland, OH 44106 USA. RP Capadona, JR (reprint author), Case Western Reserve Univ, Dept Macromol Sci & Engn, 2100 Adelbert Rd, Cleveland, OH 44106 USA. EM christoph.weder@case.edu RI Capadona, Jeffrey /G-4772-2010; Weder, Christoph/K-7453-2012; Tyler, Dustin/C-7995-2015 OI Tyler, Dustin/0000-0002-2298-8510 FU NINDS NIH HHS [R21 NS053798, R21 NS053798-01A1, R21NS053798-01] NR 37 TC 208 Z9 212 U1 19 U2 166 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1748-3387 J9 NAT NANOTECHNOL JI Nat. Nanotechnol. PD DEC PY 2007 VL 2 IS 12 BP 765 EP 769 DI 10.1038/nnano.2007.379 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Science & Technology - Other Topics; Materials Science GA 238OG UT WOS:000251456500012 PM 18654428 ER PT J AU Gubarev, MV Ramsey, BD Engelhaupt, DE Burgess, JM Mildner, DFR AF Gubarev, M. V. Ramsey, B. D. Engelhaupt, D. E. Burgess, J. M. Mildner, D. F. R. TI An evaluation of grazing-incidence optics for neutron imaging SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE atom and neutron optics; X-ray optics AB The focusing capabilities of neutron imaging optics based on the Wolter-1 geometry have been successfully demonstrated with a beam of long wavelength neutrons with low angular divergence. A test mirror was fabricated using an electroformed nickel replication process at Marshall Space Flight Center. The neutron current density gain at the focal spot of the mirror is found to be at least 8 for neutron wavelenaths in the range from 6 to 20 angstrom. Possible applications of the optics are briefly discussed. (C) 2007 Elsevier B.V. All rialus reserved. C1 [Gubarev, M. V.; Ramsey, B. D.] NASA, George C Marshall Space Flight Ctr, MSFC, Huntsville, AL 35812 USA. [Engelhaupt, D. E.] Univ Alabama, Ctr Appl Opt, Huntsville, AL 35899 USA. [Burgess, J. M.] Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. [Mildner, D. F. R.] Natl Inst Stand & Technol, Ctr Neuron Res, Gaithersburg, MD 20899 USA. RP Gubarev, MV (reprint author), NASA, George C Marshall Space Flight Ctr, MSFC, VP62, Huntsville, AL 35812 USA. EM Mikhail.V.Gubarev@nasa.gov NR 11 TC 11 Z9 11 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD DEC PY 2007 VL 265 IS 2 BP 626 EP 630 DI 10.1016/j.nimb.2007.09.041 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 246IX UT WOS:000252001800025 ER PT J AU Mather, J AF Mather, J. TI From the Big Bang to the Nobel Prize and the James Webb Space Telescope SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS LA English DT Editorial Material AB The Cosmic Background Explorer (COBE) team measured the spectrum and anisotropy of the Cosmic Microwave Background (CMB) radiation from the Big Bang to extraordinary precision, leading to the Nobel Prize in Physics in 2006. In addition, the COBE team measured the Cosmic Infrared Background radiation, showing that the Universe is twice as bright as expected from the then-known populations of galaxies. The success of this mission has already led to the WMAP (Wilkinson Microwave Anisotropy Probe) mission, the Planck mission is in preparation, and plans are being made for space missions to measure the primeval B-mode polarization of the CMB. It may eventually be possible to measure the deviations of the primeval spectrum from a black body, as predicted from the effects of disequilibrium during the decoupling. My personal work has continued in a different direction, extending the observations and discoveries of the Hubble Space Telescope (HST) to the James Webb Space Telescope (JWST). The JWST is planned for launch in 2013 as a general purpose observatory open to astronomers around the world. Its technologies are all mature and flight hardware is being made. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. RP Mather, J (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. NR 4 TC 3 Z9 3 U1 0 U2 1 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1594-9982 J9 NUOVO CIMENTO B JI Nouvo Cimento Soc. Ital. Fis. B-Gen. Phys. Relativ. Astron. Math. Phys. Methods PD DEC PY 2007 VL 122 IS 12 BP 1315 EP 1326 DI 10.1393/ncb/i2008-10489-6 PG 12 WC Physics, Multidisciplinary SC Physics GA 356EE UT WOS:000259760700001 ER PT J AU Negreiros, FR Soares, EA de Carvalho, VE Bozzolo, G AF Negreiros, F. R. Soares, E. A. de Carvalho, V. E. Bozzolo, G. TI Atomistic modeling of Au-Ag nanoparticle formation SO PHYSICAL REVIEW B LA English DT Article ID BIMETALLIC NANOPARTICLES; SURFACE; ABSORPTION; PARTICLES; NANOBOXES; NANOCAGES; COLLOIDS; CLUSTERS; SYSTEM; PD AB Atomistic modeling of the formation process of Au-Ag nanoparticles is performed using the Bozzolo-Ferrante-Smith method for alloys for the energetic. Silver segregation to the surface, surface structure and orientation, and weak Au-Ag interactions are identified as the main features driving the formation process. C1 [Negreiros, F. R.; Soares, E. A.; de Carvalho, V. E.] Univ Fed Minas Gerais, Dept Fis, BR-30123970 Belo Horizonte, MG, Brazil. [Bozzolo, G.] Ohio Aerosp Inst, Cleveland, OH 44142 USA. [Bozzolo, G.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Negreiros, FR (reprint author), Univ Fed Minas Gerais, Dept Fis, Caixa Postale 702, BR-30123970 Belo Horizonte, MG, Brazil. RI Soares, Edmar/C-2303-2013; de Carvalho, Vagner/A-4583-2008 NR 27 TC 7 Z9 7 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD DEC PY 2007 VL 76 IS 24 AR 245432 DI 10.1103/PhysRevB.76.245432 PG 5 WC Physics, Condensed Matter SC Physics GA 246DB UT WOS:000251986600113 ER PT J AU Wu, H Zhou, W Udovic, TJ Rush, JJ Yildirim, T Hartman, MR Bowman, RC Vajo, JJ AF Wu, Hui Zhou, Wei Udovic, Terrence J. Rush, John J. Yildirim, Taner Hartman, Michael R. Bowman, Robert C., Jr. Vajo, John J. TI Neutron vibrational spectroscopy and first-principles calculations of the ternary hydrides Li4Si2H(D) and Li4Ge2H(D): Electronic structure and lattice dynamics SO PHYSICAL REVIEW B LA English DT Article ID LITHIUM-SILICON; SYSTEM; SI AB Using combined neutron spectroscopy and first-principles calculations, we investigated the electronic structure and vibrational dynamics of the recently discovered class of ternary hydrides Li(4)Tt(2)H (Tt=Si and Ge). In these compounds, all hydrogen atoms are located in a single type of Li-6-defined octahedral site. The Tt atoms form long-range Tt-Tt chains sandwiched between each Li-6-octahedra layer. The Li-H interactions are strongly ionic, with bond lengths comparable to those in LiH. Our density functional theory calculations indicate that Li atoms transfer their electrons to both H and Tt atoms. Tt atoms within the Tt-Tt chain are bonded covalently. The electronic density of states reveals that both hydrides exhibit metallic behavior. The observed vibrational spectra of these hydrides are in good overall agreement with the calculated phonon modes. There is evidence of dispersion induced splitting in the optical phonon peaks that can be ascribed to the coupling of H vibrations within the Li-6-octahedra layers. C1 [Wu, Hui; Zhou, Wei; Udovic, Terrence J.; Rush, John J.; Yildirim, Taner] NIST, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. [Wu, Hui; Rush, John J.] Univ Maryland, Dept Mat Sci & Engn, College Pk, MD 20742 USA. [Zhou, Wei; Yildirim, Taner] Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. [Hartman, Michael R.] Oregon State Univ, Dept Nucl Engn & Radiat Hlth Phys, Corvallis, OR 97331 USA. [Bowman, Robert C., Jr.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Vajo, John J.] HRL Labs LLC, Malibu, CA 90265 USA. RP Wu, H (reprint author), NIST, NIST Ctr Neutron Res, 100 Bur Dr,MS 6102, Gaithersburg, MD 20899 USA. EM huiwu@nist.gov RI Wu, Hui/C-6505-2008; Zhou, Wei/C-6504-2008; yildirim, taner/A-1290-2009; OI Wu, Hui/0000-0003-0296-5204; Zhou, Wei/0000-0002-5461-3617; Bowman, Robert/0000-0002-2114-1713 NR 18 TC 15 Z9 15 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD DEC PY 2007 VL 76 IS 22 AR 224301 DI 10.1103/PhysRevB.76.224301 PG 6 WC Physics, Condensed Matter SC Physics GA 246CZ UT WOS:000251986400037 ER PT J AU D'Ambrosio, E Maleki, L Yu, N AF D'Ambrosio, Erika Maleki, Lute Yu, Nan TI Translational invariance of gravitational wave atom interferometers SO PHYSICAL REVIEW D LA English DT Article ID MATTER-WAVE AB We evaluate the transfer function of a novel kind of detector and reconcile our results with previously published calculations (whose conclusions are apparently significantly different from each other) thereby showing the natural equivalence of all considered methods. C1 [D'Ambrosio, Erika; Maleki, Lute; Yu, Nan] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP D'Ambrosio, E (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 11 TC 5 Z9 5 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 J9 PHYS REV D JI Phys. Rev. D PD DEC PY 2007 VL 76 IS 12 AR 122001 DI 10.1103/PhysRevD.76.122001 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 246DI UT WOS:000251987300007 ER PT J AU Racine, E Cutler, C AF Racine, Etienne Cutler, Curt TI Gaussianity of LISA's confusion backgrounds SO PHYSICAL REVIEW D LA English DT Article AB Data analysis for the proposed Laser Interferometer Space Antenna (LISA) will be complicated by the huge number of sources in the LISA band. In the frequency band similar to 10(-4)-2x10(-3) Hz, galactic white dwarf binaries (GWDBs) are sufficiently dense in frequency space that it will be impossible to resolve most of them, and "confusion noise" from the unresolved Galactic binaries will dominate over instrumental noise in determining LISA's sensitivity to other sources in that band. Confusion noise from unresolved extreme-mass-ratio inspirals (EMRIs) could also contribute significantly to LISA's total noise curve. To date, estimates of the effect of LISA's confusion noise on matched-filter searches and their detection thresholds have generally approximated the noise as Gaussian, based on the central limit theorem. However in matched-filter searches, the appropriate detection threshold for a given class of signals may be located rather far out on the tail of the signal-to-noise probability distribution, where a priori it is unclear whether the Gaussian approximation is reliable. Using the Edgeworth expansion and the theory of large deviations, we investigate the probability distribution of the usual matched-filter detection statistic, far out on the tail of the distribution. We apply these tools to four somewhat idealized versions of LISA data searches: searches for EMRI signals buried in GWDB confusion noise, and searches for massive black hole binary signals buried in (i) GWDB noise, (ii) EMRI noise, and (iii) a sum of EMRI noise and Gaussian noise. Assuming reasonable short-distance cutoffs in the populations of confusion sources (since the very closest and hence strongest sources will be individually resolvable), modifications to the appropriate detection threshold, due to the non-Gaussianity of the confusion noise, turn out to be quite small for realistic cases. The smallness of the correction is partly due to the fact that these three types of sources evolve on quite different time scales, so no single background source closely resembles any search template. We also briefly discuss other types of LISA searches where the non-Gaussianity of LISA's confusion backgrounds could perhaps have a much greater impact on search reliability and efficacy. C1 [Racine, Etienne] CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. [Cutler, Curt] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Racine, E (reprint author), CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. NR 10 TC 7 Z9 7 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 J9 PHYS REV D JI Phys. Rev. D PD DEC PY 2007 VL 76 IS 12 AR 124033 DI 10.1103/PhysRevD.76.124033 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 246DI UT WOS:000251987300075 ER PT J AU Langer, CA Akylas, E Kassinos, SC AF Langer, C. A. Akylas, E. Kassinos, S. C. TI Linear analysis of generalized turbulent hyperbolic flow in a rotating frame SO PHYSICS OF FLUIDS LA English DT Article AB We apply inviscid rapid distortion theory to the generalized case of turbulent hyperbolic flow in a rotating frame and investigate the dependence of the evolution of the turbulent kinetic energy on the frame rotation rate. We derive an analytical two-dimensional solution which allows for an accurate approximation of the three-dimensional initially isotropic problem. From the analytical solutions we determine a new generalized stability criterion for the evolution of the turbulent kinetic energy in this class of flows. C1 [Langer, C. A.; Akylas, E.; Kassinos, S. C.] Univ Cyprus, Dept Mech & Mfg Engn, CY-1678 Nicosia, Cyprus. [Akylas, E.] Natl Observ Athens, Inst Environm Res, Athens, Greece. [Kassinos, S. C.] NASA, Stanford Univ, Ctr Turbulence Res, Ames, IA USA. RP Kassinos, SC (reprint author), Univ Cyprus, Dept Mech & Mfg Engn, CY-1678 Nicosia, Cyprus. EM kassinos@ucy.ac.cy RI Kassinos, Stavros/B-6404-2016; Akylas, Evangelos/E-4418-2016 OI Kassinos, Stavros/0000-0002-3501-3851; Akylas, Evangelos/0000-0002-2731-657X NR 13 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 EI 1089-7666 J9 PHYS FLUIDS JI Phys. Fluids PD DEC PY 2007 VL 19 IS 12 AR 128106 DI 10.1063/1.2821911 PG 4 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 246DP UT WOS:000251988000039 ER PT J AU Argus, D AF Argus, Donald TI Where is the centre of the Earth? SO PHYSICS WORLD LA English DT Article C1 NASA, Jet Prop Lab, Pasadena, CA 91109 USA. RP Argus, D (reprint author), NASA, Jet Prop Lab, Pasadena, CA 91109 USA. EM donald.f.argus@jpl.nasa.gov RI Argus, Donald/F-7704-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8585 J9 PHYS WORLD JI Phys. World PD DEC PY 2007 VL 20 IS 12 BP 35 EP 38 PG 4 WC Physics, Multidisciplinary SC Physics GA 239DB UT WOS:000251497700032 ER PT J AU Nemecek, Z Safrankova, J Merka, J Simunek, J Prech, L AF Nemecek, Z. Safrankova, J. Merka, J. Simunek, J. Prech, L. TI Interball contribution to the high-altitude cusp observations SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT International Meeting on Dynamical Processes in Space Plasmas CY MAY 07-15, 2006 CL ISRAEL DE cusp; plasma mantle; maenetopause; magnetosheath; magnetic reconnection; low-latitude boundary layer ID INTERPLANETARY MAGNETIC-FIELD; TURBULENT-BOUNDARY-LAYER; OUTER CUSP; POLAR CUSP; LATITUDE MAGNETOPAUSE; DIPOLE TILT; LOCAL TIME; LOCATION; PLASMA; SHAPE AB The polar cusps have traditionally been described as narrow funnel-shaped regions of magnetospheric magnetic field lines directly connected to magnetosheath, allowing the magnetosheath plasma to precipitate into the ionosphere. However, recent observations and theoretical considerations revealed that the formation of the cusp cannot be treated separately from the processes along the whole dayside magnetopause and that the plasma in regions like cleft or low-latitude boundary layer is of the same origin. Our review of statistical results as well as numerous case studies identified the anti-parallel merging at the magnetopause as the principal source of the magnetosheath plasma in all altitudes. Since effective merging requires a low plasma speed at the reconnection spot, we have found that the magnetopause shape and especially its indentation at the outer cusp is a very important part of the whole process. The plasma is slowed down in this indentation and arising multiscale turbulent processes enhance the reconnection rate. (c) 2007 Elsevier Ltd. All rights reserved. C1 [Safrankova, J.; Prech, L.] Charles Univ Prague, Fac Math & Phys, CR-18000 Prague 8, Czech Republic. [Merka, J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Simunek, J.] Acad Sci Czech Republic, Inst Atmospher Phys, Prague 14131 4, Czech Republic. RP Nemecek, Z (reprint author), Charles Univ Prague, Fac Math & Phys, V Holesovickach 2, CR-18000 Prague 8, Czech Republic. EM zdenek.nemecek@mff.cu.ni.cz RI Simunek, Jiri/H-8139-2014 NR 44 TC 3 Z9 3 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2007 VL 55 IS 15 BP 2286 EP 2294 DI 10.1016/j.pss.2007.05.021 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 243RL UT WOS:000251814900013 ER PT J AU Safrankova, J Nemecek, Z Prech, L Samsonov, AA Koval, A Andreeova, K AF Safrankova, J. Nemecek, Z. Prech, L. Samsonov, A. A. Koval, A. Andreeova, K. TI Interaction of interplanetary shocks with the bow shock SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT International Meeting on Dynamical Processes in Space Plasmas CY MAY 07-15, 2006 CL ISRAEL DE solar wind interaction; upstream conditions; magnetopause; magnetosheath; MHD modeling; interplanetary shock ID SOLAR-WIND; MAGNETOPAUSE; WAVES; MAGNETOSPHERE; ORIGIN AB Fast forward interplanetary (IP) shocks have been identified as a source of large geomagnetic disturbances. However, the shocks can evolve in the solar wind, they are modified by interaction with the bow shock and during their propagation through the magnetosheath. A few previous papers refer the inclination and deceleration of the IP shock front in this region. Our contribution continues this effort and presents the study of an IP shock interaction with the bow shock. Since the bow shock is a reversed fast shock, the interaction of the IP shock and bow shock is a problem of interaction of two fast MHD shocks. We compare profiles of magnetic field and plasma parameters observed by several spacecraft in the solar wind and magnetosheath with the profiles of the same parameters resulting from the MHD numerical model. The MHD model suggests that the interaction of an IP shock with the bow shock results in an inward bow shock displacement that is followed by its outward motion. Such motion will result in an indentation propagating along the bow shock surface. This scenario is confirmed by multipoint observations. Moreover, the model confirms also previous suggestions on the IP shock deceleration in the magnetosheath. (c) 2007 Elsevier Ltd. All rights reserved. C1 [Safrankova, J.; Nemecek, Z.; Prech, L.; Andreeova, K.] Charles Univ Prague, Fac Math & Phys, CR-18000 Prague 8, Czech Republic. [Samsonov, A. A.] St Petersburg State Univ, Inst Phys, St Petersburg, Russia. [Koval, A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Safrankova, J (reprint author), Charles Univ Prague, Fac Math & Phys, V Holesovickach 2, CR-18000 Prague 8, Czech Republic. EM jana.safrankova@mff.cuni.cz RI Samsonov, Andrey/I-7057-2012 OI Samsonov, Andrey/0000-0001-8243-1151 NR 23 TC 7 Z9 7 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2007 VL 55 IS 15 BP 2324 EP 2329 DI 10.1016/j.pss.2007.05.012 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 243RL UT WOS:000251814900019 ER PT J AU Johnson, NL AF Johnson, N. L. TI Developments in space debris mitigation policy and practices SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART G-JOURNAL OF AEROSPACE ENGINEERING LA English DT Article DE space debris; mitigation; policy AB Since the American Institute of Aeronautics and Astronautics issued the first position paper on space debris 25 years ago, recognition of the threats posed by debris in Earth orbit and the need to act now to protect the future space environment have become widespread. This new awareness has been matched with positive actions by spacecraft and launch vehicle designers, manufacturers, and operators. As a result, a common set of space debris mitigation policies and practices has been forming at both the national and international levels. C1 NASA, Johnson Space Ctr, Washington, DC 20546 USA. RP Johnson, NL (reprint author), NASA, Johnson Space Ctr, Washington, DC 20546 USA. EM nicholas.l.johnson@nasa.gov NR 0 TC 5 Z9 5 U1 0 U2 1 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI WESTMINISTER PA 1 BIRDCAGE WALK, WESTMINISTER SW1H 9JJ, ENGLAND SN 0954-4100 J9 P I MECH ENG G-J AER JI Proc. Inst. Mech. Eng. Part G-J. Aerosp. Eng. PD DEC PY 2007 VL 221 IS G6 BP 907 EP 909 DI 10.1243/09544100JAERO166 PG 3 WC Engineering, Aerospace; Engineering, Mechanical SC Engineering GA 246YM UT WOS:000252044300002 ER PT J AU Zhou, DK Smith, WL Cuomo, V Taylor, JP Barnet, CD Di Girolamo, P Pappalardo, G Larar, AM Liu, X Newman, SM Lee, C Mango, SA AF Zhou, Daniel K. Smith, William L. Cuomo, Vincenzo Taylor, Jonathan P. Barnet, Christopher D. Di Girolamo, Paolo Pappalardo, Gelsomina Larar, Allen M. Liu, Xu Newman, Stuart M. Lee, Clare Mango, Stephen A. TI Retrieval validation during the European aqua thermodynamic experiment SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE EAQUATE; AIRS; NPOESS; NAST-I; retrieval; validation ID SEA-SURFACE TEMPERATURE; NAST-I; AIRS; EMISSIVITY AB Atmospheric and surface thermodynamic parameters retrieved with advanced hyperspectral remote sensors aboard Earth observing satellites are critical to weather prediction and scientific research. The retrieval algorithms and retrieved parameters from satellite sounders must be validated to demonstrate the capability and accuracy of both observation and data processing systems. The European Aqua Thermodynamic Experiment (EAQUATE) was conducted not only for validation of the Atmospheric InfraRed Sounder on the Aqua satellite, but also for assessment of validation systems of both ground-based and aircraft-based instruments that will be used for other satellite systems, such as the Infrared Atmospheric Sounding Interferometer on the European MetOp satellite, the Cross-track Infrared Sounder from the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project and the continuing series of NPOESS satellites. Detailed intercomparisons were conducted and presented using different retrieval methodologies: measurements from airborne ultraspectral Fourier transform spectrometers, aircraft in situ instruments, dedicated dropsondes and radiosondes, ground-based Raman lidar, as well as the European Centre for Medium-range Weather Forecasting modelled thermal structures. The results of this study not only illustrate the quality of the measurements and retrieval products, but also demonstrate the capability of the validation systems put in place to validate current and future hyperspectral sounding instruments and their scientific products. Copyright (C) 2007 Royal Meteorological Society. C1 [Zhou, Daniel K.; Larar, Allen M.; Liu, Xu] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Smith, William L.] Hampton Univ, Hampton, VA 23668 USA. [Smith, William L.] Univ Wisconsin, Madison, WI USA. [Cuomo, Vincenzo; Pappalardo, Gelsomina] CNR, IMAA, Tito, Potenza, Italy. [Taylor, Jonathan P.; Newman, Stuart M.; Lee, Clare] Met Off, Exeter, Devon, England. [Barnet, Christopher D.] NOAA NESDIS, Camp Springs, MD USA. [Di Girolamo, Paolo] Univ Basilicata, DIFA, I-85100 Potenza, Italy. [Mango, Stephen A.] NPOESS Integrated Program Off, Silver Spring, MD USA. RP Zhou, DK (reprint author), NASA, Langley Res Ctr, Mail Stop 401A, Hampton, VA 23681 USA. EM Daniel.k.zhou@nasa.gov RI Barnet, Christopher/F-5573-2010; Taylor, Jonathan/B-3786-2013 NR 34 TC 11 Z9 11 U1 1 U2 3 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0035-9009 EI 1477-870X J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD DEC PY 2007 VL 133 SU 3 BP 203 EP 215 DI 10.1002/qj.181 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 259ES UT WOS:000252922500003 ER PT J AU Zhou, DK Larar, AM Liu, X Smith, WL Taylor, JP Newman, SM Sachse, GW Mango, SA AF Zhou, Daniel K. Larar, Allen M. Liu, Xu Smith, William L. Taylor, Jonathan P. Newman, Stuart M. Sachse, Glen W. Mango, Stephen A. TI NAST-I tropospheric CO retrieval validation during INTEX-NA and EAQUATE SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE ultraspectral sounder; NPOESS; CO; retrieval ID CARBON-MONOXIDE; EMISSION SPECTROMETER; FAST-RESPONSE; SATELLITE; MOPITT; METHODOLOGY; INSTRUMENT; SYSTEMS AB Troposphere carbon monoxide (CO), as well as other trace species retrieved with advanced ultraspectral remote sensors of Earth observing satellites, is critical in air quality observation, modelling, and forecasting. The retrieval algorithm and the accuracy of the parameters retrieved from passive satellite remote sounders must be validated. The Intercontinental Chemical Transport Experiment - North America (INTEXNA) and the European Aqua Thermodynamic Experiment (EAQUATE) provide important validation of satellite observations with ongoing satellite measurement programmes such as Terra, Aura, and Aqua. One of the experimental objectives is to validate chemical species observed from ultraspectral sounders with aircraft in situ measurements, such as the NPOESS Airborne Sounder Testbed-Interferometer (NAST-I). Detailed intercomparisons between aircraft in situ measured and NAST-I retrieved CO profiles were performed to assess the retrieval capability of a passive infrared spectral remote sounder. Validation results illustrate that the CO vertical structure can be obtained by the NAST-I. The thermal radiances are most sensitive to CO emissions from the free troposphere. However, the profile retrieval accuracy depends on the CO uncertainty in the terrestrial boundary layer. It is shown here that the CO distribution in the terrestrial boundary layer over the sea cannot be obtained with reliable accuracy where there is little contrast between the surface air and surface skin temperature. Copyright (C) 2007 Royal Meteorological Society. C1 [Zhou, Daniel K.; Larar, Allen M.; Liu, Xu; Sachse, Glen W.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Smith, William L.] Hampton Univ, Hampton, VA 23668 USA. [Smith, William L.] Univ Wisconsin, Madison, WI USA. [Taylor, Jonathan P.; Newman, Stuart M.] Met Off, Exeter, Devon, England. [Mango, Stephen A.] NPOESS Integrated Program Off, Silver Spring, MD USA. RP Zhou, DK (reprint author), NASA, Langley Res Ctr, Mail Stop 401 A, Hampton, VA 23681 USA. EM daniel.k.zhou@nasa.gov RI Taylor, Jonathan/B-3786-2013 NR 31 TC 1 Z9 1 U1 1 U2 5 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD DEC PY 2007 VL 133 BP 233 EP 241 DI 10.1002/qj.130 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 259ES UT WOS:000252922500005 ER PT J AU Liu, X Zhou, DK Larar, A Smith, WL Mango, SA AF Liu, Xu Zhou, Daniel K. Larar, Allen Smith, William L. Mango, Stephen A. TI Case-study of a principal-component-based radiative transfer forward model and retrieval algorithm using EAQUATE data SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE remote sensing; inversion algorithm; physical retrievals; atmospheric profiles ID NUMERICAL WEATHER PREDICTION; TROPOSPHERIC EMISSION SPECTROMETER; SOUNDING INTERFEROMETER RADIANCES; CHANNEL SELECTION; NAST-I; SATELLITE; AIRS; SYSTEM; GAS; AIRS/AMSU/HSB AB The objective of the paper is to apply a novel radiative transfer model and a physical retrieval algorithm to hyperspectral data taken during the European Aqua Atmospheric Thermodynamics Experiment (EAQUATE) campaign. A principal-component-based radiative transfer model (PCRTM) is used to calculate projection coefficients of the radiance spectrum onto a set of predefined empirical orthogonal functions (EOFs) and associated derivatives with respect to the state vector. Instead of fitting channel radiances, the physical retrieval algorithm iteratively fits the principal component (PC) scores or the EOF projection coefficients of the observed radiance spectrum using the PCRTM as its forward model. Since the EOFs are orthonormal to each other, only a few PC scores are needed to capture the information content of the radiance spectrum, therefore reducing the computational time needed for running both the forward model and the inversion. This paper demonstrates the application of such a physical algorithm for retrieving atmospheric temperature, moisture and ozone profiles, and surface properties such as surface skin temperature and surface emissivity. The results have been compared with those obtained with a NAST-I channel-based physical retrieval algorithm and with those obtained from collocated radiosonde and LIDAR measurements. Copyright (C) 2007 Royal Meteorological Society C1 [Liu, Xu; Zhou, Daniel K.; Larar, Allen] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Smith, William L.] Hampton Univ, Hampton, VA 23668 USA. [Mango, Stephen A.] NPOESS Integrated Program Off, Silver Spring, MD USA. RP Liu, X (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM Xu.Liu-1@nasa.gov NR 60 TC 14 Z9 14 U1 0 U2 5 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0035-9009 EI 1477-870X J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD DEC PY 2007 VL 133 SU 3 BP 243 EP 256 DI 10.1002/qj.156 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 259ES UT WOS:000252922500006 ER PT J AU Atwood, WB Michelson, PF Ritz, S AF Atwood, William B. Michelson, Peter F. Ritz, Steven TI Window on the extreme universe SO SCIENTIFIC AMERICAN LA English DT Article C1 [Michelson, Peter F.] Stanford Univ, Stanford, CA 94305 USA. [Ritz, Steven] NASA, Goddard Space Flight Ctr, Washington, DC 20546 USA. [Ritz, Steven] Univ Maryland, College Pk, MD 20742 USA. RP Atwood, WB (reprint author), Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU NATURE PUBLISHING GROUP PI NEW YORK PA 75 VARICK ST, 9TH FLR, NEW YORK, NY 10013-1917 USA SN 0036-8733 J9 SCI AM JI Sci.Am. PD DEC PY 2007 VL 297 IS 6 BP 54 EP 61 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 243NQ UT WOS:000251805000031 ER PT J AU Lee, ZP Carder, K Arnone, R He, MX AF Lee, ZhongPing Carder, Kendall Arnone, Robert He, MingXia TI Determination of primary spectral bands for remote sensing of aquatic environments SO SENSORS LA English DT Article DE ocean-color remote sensing; spectral bands ID INHERENT OPTICAL-PROPERTIES; WATER-LEAVING RADIANCE; OCEAN COLOR; SHALLOW WATERS; RED-TIDE; CASE-I; REFLECTANCE; MODEL; PHYTOPLANKTON; ABSORPTION AB About 30 years ago, NASA launched the first ocean-color observing satellite: the Coastal Zone Color Scanner. CZCS had 5 bands in the visible-infrared domain with an objective to detect changes of phytoplankton ( measured by concentration of chlorophyll) in the oceans. Twenty years later, for the same objective but with advanced technology, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS, 7 bands), the Moderate-Resolution Imaging Spectrometer ( MODIS, 8 bands), and the Medium Resolution Imaging Spectrometer (MERIS, 12 bands) were launched. The selection of the number of bands and their positions was based on experimental and theoretical results achieved before the design of these satellite sensors. Recently, Lee and Carder ( 2002) demonstrated that for adequate derivation of major properties ( phytoplankton biomass, colored dissolved organic matter, suspended sediments, and bottom properties) in both oceanic and coastal environments from observation of water color, it is better for a sensor to have similar to 15 bands in the 400-800 nm range. In that study, however, it did not provide detailed analyses regarding the spectral locations of the 15 bands. Here, from nearly 400 hyperspectral (similar to 3nm resolution) measurements of remote-sensing reflectance ( a measure of water color) taken in both coastal and oceanic waters covering both optically deep and optically shallow waters, first- and second-order derivatives were calculated after interpolating the measurements to 1-nm resolution. From these derivatives, the frequency of zero values for each wavelength was accounted for, and the distribution spectrum of such frequencies was obtained. Furthermore, the wavelengths that have the highest appearance of zeros were identified. Because these spectral locations indicate extrema ( a local maximum or minimum) of the reflectance spectrum or inflections of the spectral curvature, placing the bands of a sensor at these wavelengths maximizes the potential of capturing ( and then restoring) the spectral curve, and thus maximizes the potential of accurately deriving properties of the water column and/or bottom of various aquatic environments with a multi-band sensor. C1 [Lee, ZhongPing; Arnone, Robert] USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. [Carder, Kendall] Univ S Florida, Coll Marine Sci, St Petersburg, FL 33701 USA. [He, MingXia] Ocean Univ China, Ocean Remote Sensing Inst, Qingdao, Peoples R China. RP Lee, ZP (reprint author), USN, Res Lab, Stennis Space Ctr, Code 7333, Stennis Space Ctr, MS 39529 USA. EM zplee@nrlssc.navy.mil NR 34 TC 37 Z9 37 U1 1 U2 15 PU MOLECULAR DIVERSITY PRESERVATION INT PI BASEL PA MATTHAEUSSTRASSE 11, CH-4057 BASEL, SWITZERLAND SN 1424-8220 J9 SENSORS-BASEL JI Sensors PD DEC PY 2007 VL 7 IS 12 BP 3428 EP 3441 DI 10.3390/s7123428 PG 14 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 255AE UT WOS:000252628300028 ER PT J AU DeCastro, JA Melcher, KJ Noebe, RD Gaydosh, DJ AF DeCastro, J. A. Melcher, K. J. Noebe, R. D. Gaydosh, D. J. TI Development of a numerical model for high-temperature shape memory alloys SO SMART MATERIALS & STRUCTURES LA English DT Article ID POSITION CONTROL; SMART STRUCTURES; CONTROL-SYSTEM; HYSTERESIS; ACTUATOR; TRACKING AB A new thermomechanical hysteresis model for a high-temperature shape memory alloy (HTSMA) actuator material is presented. The proposed Brinson-Preisach model is capable of predicting the strain output of a tensile-loaded HTSMA when excited by arbitrary temperature-stress inputs for the purpose of actuator and control design. Quasistatic generalized Preisach hysteresis models available in the literature require large sets of experimental data for model identification at a particular operating point, and substantially more data for multiple operating points. The minor loop algorithm is an alternate approach to common Preisach methods that is better suited for research-stage alloys, such as recently developed HTSMAs, for which a complete identification database is not yet available. A detailed description of the minor loop hysteresis algorithm is presented in this paper and a methodology for determination of model parameters is introduced. The algorithm is assembled together with a modified form of the one-dimensional Brinson constitutive equation to provide a continuous thermomechanical response even within the characteristically wide detwinning region of the HTSMA. The computationally efficient algorithm is shown to demonstrate each of the unique characteristics of Preisach minor loop hysteresis over the usable actuation range in high-stress, high-temperature applications. C1 [DeCastro, J. A.] ASRC Aerrosp Corp, Cleveland, OH 44135 USA. [Noebe, R. D.; Gaydosh, D. J.] NASA, Glenn Res Ctr, Adv Met Branch, Cleveland, OH 44135 USA. [Gaydosh, D. J.] Ohio Aerosp Inst, Cleveland, OH 44135 USA. RP DeCastro, JA (reprint author), ASRC Aerrosp Corp, Cleveland, OH 44135 USA. NR 24 TC 15 Z9 15 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD DEC PY 2007 VL 16 IS 6 BP 2080 EP 2090 DI 10.1088/0964-1726/16/6/011 PG 11 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 253QM UT WOS:000252532700012 ER PT J AU Michalek, G Gopalswamy, N Yashiro, S AF Michalek, G. Gopalswamy, N. Yashiro, S. TI Prediction of space weather using an asymmetric cone model for halo CMEs SO SOLAR PHYSICS LA English DT Article DE Sun; solar activity; Sun; coronal mass ejections; Sun; space weather ID CORONAL MASS EJECTIONS; GEOMAGNETIC STORMS; LASCO; SOHO; INTENSITY; SPEEDS; EIT AB Halo coronal mass ejections (HCMEs) are responsible of the most severe geomagnetic storms. A prediction of their geoeffectiveness and travel time to Earth's vicinity is crucial to forecast space weather. Unfortunately, coronagraphic observations are subjected to projection effects and do not provide true characteristics of CMEs. Recently, Michalek (Solar Phys. 237, 101, 2006) developed an asymmetric cone model to obtain the space speed, width, and source location of HCMEs. We applied this technique to obtain the parameters of all front-sided HCMEs observed by the SOHO/LASCO experiment during a period from the beginning of 2001 until the end of 2002 (solar cycle 23). These parameters were applied for space weather forecasting. Our study finds that the space speeds are strongly correlated with the travel times of HCMEs to Earth's vicinity and with the magnitudes related to geomagnetic disturbances. C1 Jagiellonian Univ, Astron Observ, Krakow, Poland. NASA, Solar Syst Explorat Div, GSFC, Greenbelt, MD USA. Catholic Univ Amer, Ctr Solar & Space Weather, Washington, DC USA. RP Michalek, G (reprint author), Jagiellonian Univ, Astron Observ, Krakow, Poland. EM michalek@oa.uj.edu.pl RI Gopalswamy, Nat/D-3659-2012 NR 37 TC 11 Z9 11 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 2007 VL 246 IS 2 BP 399 EP 408 DI 10.1007/s11207-007-9081-8 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 238DH UT WOS:000251427000007 ER PT J AU Michalek, G Gopalswamy, N Xie, H AF Michalek, G. Gopalswamy, N. Xie, H. TI Width of radio-loud and radio-quiet CMEs SO SOLAR PHYSICS LA English DT Article DE Sun; solar activity; Sun; coronal mass ejections; Sun; solar radio emission ID CORONAL MASS EJECTIONS; II BURSTS; SPACECRAFT; SOHO; WAVE AB In the present paper we report on the difference in angular sizes between radio-loud and radio-quiet CMEs. For this purpose we compiled these two samples of events using Wind/WAVES and SOHO/LASCO observations obtained during 1996-2005. We show that the radio-loud CMEs are almost twice as wide as the radio-quiet CMEs (considering expanding parts of CMEs). Furthermore, we show that the radio-quiet CMEs have a narrow expanding bright part with a large extended diffusive structure. These results were obtained by measuring the CME widths in three different ways. C1 Jagiellonian Univ, Astron Observ, Krakow, Poland. NASA, Solar Syst Explorat Div, GSFC, Greenbelt, MD USA. Catholic Univ Amer, Ctr Solar & Space Weather, Washington, DC USA. RP Michalek, G (reprint author), Jagiellonian Univ, Astron Observ, Krakow, Poland. EM michalek@oa.uj.edu.pl RI Gopalswamy, Nat/D-3659-2012 NR 19 TC 11 Z9 11 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 2007 VL 246 IS 2 BP 409 EP 414 DI 10.1007/s11207-007-9062-y PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 238DH UT WOS:000251427000008 ER PT J AU Campbell, J AF Campbell, Joel TI The SMM model as a boundary value problem using the discrete diffusion equation SO THEORETICAL POPULATION BIOLOGY LA English DT Article DE discrete diffusion; SMM; stepwise mutation; infinite alleles; microsatellite; n-step; bessel ID ELECTROPHORETICALLY DETECTABLE ALLELES; MICROSATELLITE LOCI; GENETIC DISTANCES; MUTATION; EVOLUTION AB A generalized single-step stepwise mutation model (SMM) is developed that takes into account an arbitrary initial state to a certain partial difference equation. This is solved in both the approximate continuum limit and the more exact discrete form. A time evolution model is developed for Y DNA or mtDNA that takes into account the reflective boundary modeling minimum microsatellite length and the original difference equation. A comparison is made between the more widely known continuum Gaussian model and a discrete model, which is based on modified Bessel functions of the first kind. A correction is made to the SMM model for the probability that two individuals are related that takes into account a reflecting boundary modeling minimum microsatellite length. This method is generalized to take into account the general n-step model and exact solutions are found. A new model is proposed for the step distribution. Published by Elsevier Inc. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Campbell, J (reprint author), NASA, Langley Res Ctr, MS 488, Hampton, VA 23681 USA. EM joel.f.campbell@nasa.gov NR 23 TC 4 Z9 4 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0040-5809 J9 THEOR POPUL BIOL JI Theor. Popul. Biol. PD DEC PY 2007 VL 72 IS 4 BP 539 EP 546 DI 10.1016/j.tpb.2007.08.001 PG 8 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA 236CA UT WOS:000251279400008 PM 17884123 ER PT J AU Marantidou, O Loukopoulou, L Zervou, E Martinis, G Egglezou, A Fountouli, P Dimoxenous, P Parara, M Gavalaki, M Maniatis, A AF Marantidou, O. Loukopoulou, L. Zervou, E. Martinis, G. Egglezou, A. Fountouli, P. Dimoxenous, P. Parara, M. Gavalaki, M. Maniatis, A. TI Factors that motivate and hinder blood donation in Greece SO TRANSFUSION MEDICINE LA English DT Article DE blood; incentives; perception; replacement risk; volunteer ID UNITED-STATES; DONORS; RECRUITMENT; INCENTIVES; VOLUNTEER; BEHAVIOR; IMPACT; IRON AB Donations in Greece are insufficient to cover the high transfusion needs arising from large numbers of thalassaemia and sickle cell anaemia patients and the implementation of new surgical techniques. Efforts to achieve self-sufficiency, and to render blood supplies safer and manageable must focus on recruiting and retaining more volunteer donors and on converting the large pool of replacement donors. The aim of the study was to gain insight into public perception regarding the risks of donation and transfusion and to identify the factors that would motivate more people in Greece to regularly donate blood. Questionnaires were distributed to 1600 donors at the blood bank and visitors to hospitals at 11 locations across the country. Data on demographics, donation behaviour, incentives, risk perception and attitudes towards donation and transfusion were analysed separately for volunteer and replacement donors and non-donors. The results showed that women and young people donate the least in Greece. Also, many donors do not donate because they are not reminded to. A small percentage of donors confessed to having concealed part of the truth to background questions. Overall, incentives to donate were considered important and included future availability of blood for self or family, paid leave from work and free blood tests. Recruitment and retention efforts should include better communication with current donors, and raising awareness among eligible donors. Staff should be educated in soliciting information from potential donors, and incentives should be better aligned to avoid conflict with ethical values and ensure honesty in the prescreening process. C1 Asklipeion Hosp, Blood Bank, Athens, Greece. San Jose State Univ, NASA, Ames Res Ctr, San Jose, CA USA. Univ Hosp Ioannina, Blood Bank, Ioannina, Greece. Univ Hosp Alexandroupolis, Blood Bank, Alexandroupolis, Greece. Papanikolaou Hosp, Blood Bank, Thessaloniki, Greece. Univ Hosp Hrakleio, Blood Bank, Crete, NE USA. Mamatseio Hosp, Blood Bank, Kozani, Greece. Euaggelismos Hosp, Blood Bank, Athens, Greece. Laikon Gen Hosp, Blood Bank, Athens, Greece. Henry Dunan Hosp, Haematol Clin, Athens, Greece. RP Marantidou, O (reprint author), Asklipeion Hosp, Blood Bank, Athens, Greece. EM olga_marantidou@hotmail.com NR 32 TC 33 Z9 35 U1 1 U2 2 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0958-7578 J9 TRANSFUSION MED JI Transfus. Med. PD DEC PY 2007 VL 17 IS 6 BP 443 EP 450 DI 10.1111/j.1365-3148.2007.00797.x PG 8 WC Hematology SC Hematology GA 236UX UT WOS:000251330000003 PM 18067648 ER PT J AU Giles, KA Laxon, SW Wingham, DJ Wallis, DW Krabill, WB Leuschen, CJ McAdoo, D Manizade, SS Raney, RK AF Giles, K. A. Laxon, S. W. Wingham, D. J. Wallis, D. W. Krabill, W. B. Leuschen, C. J. McAdoo, D. Manizade, S. S. Raney, R. K. TI Combined airborne laser and radar altimeter measurements over the Fram Strait in May 2002 SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE radar altimetry; laser altimetry; sea ice thickness; snow depth ID SEA-ICE; ARCTIC ICE; THICKNESS; LAND AB Knowledge of sea ice thickness is critical for the prediction of future climate, and for assessing the significance of changes in thickness. Sea ice thickness can be calculated from radar or laser satellite altimetry measurements of freeboard. However, a lack of knowledge of snow depth introduces significant uncertainties into these calculations. This paper compares the first coincident airborne laser and radar altimetry data over sea ice, collected during the Laser Radar Altimetry (LaRA) field campaign. LaRA was a flight of opportunity that provided valuable data to explore techniques to validate satellite measurements of ice freeboard, and the possibility of combining laser and radar measurements over snow covered sea ice to calculate the snow depth. Two new methods were created to analyse these data sets: a new radar retracker and a radar power simulator, which models radar returns from the laser data. We present the first quantitative analysis of data from the LaRA laser and radar altimeters, and demonstrate the potential of combining laser and radar altimetry to estimate snow depth. LaRA elevation estimates compare well with elevations from the radar altimeter onboard ERS-2 at the sub-meter level and the study provides lessons for future validation of satellite altimetry data over sea ice. Laser elevations are consistently higher than the radar elevations over snow covered sea ice. As LaRA was a flight of opportunity, no coincident in-situ measurements were available. Nevertheless, the difference between the reflecting surface of the laser and radar is consistent with snow depth from climatology and the analysis techniques developed in this paper will be useful for future radar and laser altimetry comparisons. (c) 2007 Elsevier Inc. All rights reserved. C1 UCL, Ctr Polar Observat & Modelling, London WC1E 6BT, England. NASA, Goddard Space Flight Ctr, Cryospher Sci Branch, Wallops Isl, VA 23337 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NOAA, Lab Satellite Altimetry, Silver Spring, MD 20910 USA. NASA, Wallops Flight Facil, EG&G Techn Serv, Wallops Isl, VA 23337 USA. RP Giles, KA (reprint author), UCL, Ctr Polar Observat & Modelling, Gower St, London WC1E 6BT, England. EM k.giles@cpom.ucl.ac.uk RI Giles, Katharine/G-3837-2010; Laxon, Seymour/C-1644-2008; McAdoo, Dave/F-5612-2010 OI McAdoo, Dave/0000-0002-7533-5564 NR 31 TC 50 Z9 50 U1 1 U2 14 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 EI 1879-0704 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD NOV 30 PY 2007 VL 111 IS 2-3 BP 182 EP 194 DI 10.1016/j.rse.2007.02.037 PG 13 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 234QF UT WOS:000251178000006 ER PT J AU Tedesco, M Kokhanovsky, AA AF Tedesco, M. Kokhanovsky, A. A. TI The semi-analytical snow retrieval algorithm and its application to MODIS data SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE grain size; MODIS; snow retrieval ID GRAIN-SIZE; BIDIRECTIONAL REFLECTANCE; ASYMPTOTIC THEORY; SPECTRAL ALBEDO; SURFACE-AREA; IN-SITU; SCATTERING; LIGHT; MODEL AB Grain size is a key parameter of a snowpack, affecting its thermodynamic state and influencing the spectral snow albedo. Differently from visible wavelengths, where the sensitivity to grain size is very low, in the near-infrared band there is a strong sensitivity of the reflectance to the grain size. This sensitivity provides the basis for the retrieval of grain size. In this paper we introduce a new snow retrieval algorithm that makes use of near-infrared measurements in which snow is modeled as a semi-infinite, weakly absorbing medium. It is assumed that the dense packing effects can be neglected and the radiative transport in snow can be studied using the standard radiative transfer equation extensively used, e.g., in cloud optics. The shape of grains is accounted for in the framework of fractal snow grain model. The performance of the algorithm is evaluated using ground-based measurements of snow albedo and results from a different retrieval algorithm. The technique is applied to study the changes of snow properties before and just after snow fall as seen by two MODIS sensors on TERRA and AQUA satellites. These satellites fly approximately 3 h and half apart (10:30 a.m. and 1:30 p.m. equator crossing time). The values of grain size retrieved from MODIS are also compared with values of grain size collected on ground. However, the area observed by MODIS including the locations of ground measurements was completely covered by clouds on the date of the measurements and the comparison could be performed only for the two previous days. A sensitivity analysis of the retrieval error due to atmospheric correction is also performed. Results show that the error on grain size retrieval induced by atmospheric correction ranges between +/- 5% and +/- 40%, depending on the grain size. (c) 2007 Elsevier Inc. All rights reserved. C1 Univ Maryland Baltimore Cty, GEST, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Bremen, Inst Environm Phys, D-28334 Bremen, Germany. RP Tedesco, M (reprint author), Univ Maryland Baltimore Cty, GEST, Baltimore, MD 21228 USA. EM mtedesco@umbc.edu RI Tedesco, Marco/F-7986-2015; Kokhanovsky, Alexander/C-6234-2016 OI Kokhanovsky, Alexander/0000-0001-7370-1164 NR 35 TC 24 Z9 27 U1 0 U2 9 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 EI 1879-0704 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD NOV 30 PY 2007 VL 111 IS 2-3 BP 228 EP 241 DI 10.1016/j.rse.2007.02.036 PG 14 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 234QF UT WOS:000251178000010 ER PT J AU Moody, EG King, MD Schaaf, CB Hall, DK Platnick, S AF Moody, Eric G. King, Michael D. Schaaf, Crystal B. Hall, Dorothy K. Platnick, Steven TI Northern Hemisphere five-year average (2000-2004) spectral albedos of surfaces in the presence of snow: Statistics computed from Terra MODIS land products SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE Moderate Resolution Imaging Spectroradiometer (MODIS); radiative transfer; remote sensing; satellite applications; spectral surface albedo; Terra; vegetation; ecosystem; modeling; snow ID GENERAL-CIRCULATION MODELS; OPTICAL-PROPERTIES; BOREAL FOREST; GRAIN-SIZE; CLIMATE; COVER; ICE; ALGORITHMS; CLOUD; WATER AB In this paper, we present five-year (2000-2004) climatological statistics of Northern Hemisphere spectral white-sky albedo for the 16 International Geosphere-Biosphere Program (IGBP) ecosystem classes when accompanied by the presence of snow on the ground. These statistics are obtained using validated, high quality Moderate Resolution Imaging Spectroradiometer (MODIS) land surface albedo (MOD43B3) data flagged as snow in the associated Quality Assurance (QA) fields. Near Real-Time Ice and Snow Extent (NISE) data are used as an additional discriminator of snow extent. Statistics are provided for the first seven MODIS bands, ranging from 0.47 to 2.1 mu m, and for three broadbands, 0.3-0.7, 0.3-5.0 and 0.7-5.0 mu m. The statistics demonstrate that each ecosystem classification has a discernible spectral albedo signature when accompanied by snow on the ground. This indicates that winter canopy and the underlying surface radiative properties are impacted by the presence of snow overlying these surfaces. For example, the 0.47 mu m albedo of winter snow-free evergreen needleleaf forests increases from 0.03 to 0.36 in the presence of snow, compared to an increase of 0.04 to 0.76 for croplands. In general, the albedo of snow-covered ecosystems with some winter canopy has lower albedos than ecosystems with little to no winter canopy; for example the 0.47 mu m albedo of snow-covered mixed forests is 0.39 compared to 0.87 for barren/deserts and 0.95 for permanent snow. These statistics can be used within land surface models in a stand-alone mode, to prescribe albedo values in atmospheric General Circulation Models (GCMs), or be incorporated into research and operational projects. They are intended to provide researchers with representative spectral albedo values of IGBP ecosystems in the presence of snow that are derived from validated satellite data. (c) 2007 Elsevier Inc. All rights reserved. C1 RS Informat Syst Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Div Earth Sci, Greenbelt, MD 20771 USA. Boston Univ, Dept Geog, Ctr Remote Sensing, Boston, MA 02215 USA. NASA, Goddard Space Flight Ctr, Cryospher Sci Branch, Greenbelt, MD 20771 USA. RP Moody, EG (reprint author), RS Informat Syst Inc, Lanham, MD 20706 USA. EM moody@climate.gsfe.nasa.gov RI King, Michael/C-7153-2011; Hall, Dorothy/D-5562-2012; Platnick, Steven/J-9982-2014 OI King, Michael/0000-0003-2645-7298; Platnick, Steven/0000-0003-3964-3567 NR 51 TC 49 Z9 49 U1 1 U2 9 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD NOV 30 PY 2007 VL 111 IS 2-3 BP 337 EP 345 DI 10.1016/j.rse.2007.03.026 PG 9 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 234QF UT WOS:000251178000015 ER PT J AU Tedesco, M Miller, J AF Tedesco, M. Miller, J. TI Observations and statistical analysis of combined active-passive microwave space-borne data and snow depth at large spatial scales SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE microwave remote sensing; active and passive; snow; snow depth ID NASA SCATTEROMETER NSCAT; WATER EQUIVALENT; SSM/I DATA; ALGORITHM; RETRIEVAL AB Remote sensing based on active and passive microwave data represents a useful tool for studying the state of the cryosphere at high temporal resolution and large spatial scale. In particular, retrieving snow parameters from space-borne data can benefit hydrological, meteorological, and climatological applications. In this paper, we analyze the trend of Ku band backscatter coefficients measured by the NASA's Quick Scatterometer (QuikSCAT) and K and Ka band brightness temperatures measured by the Special Sensor Microwave Imager (SSM/I) with respect to snow depth values at different locations in the Northern hemisphere during the period 1999-2004. We also quantify, for the first time, the dynamic range of space-borne Ku band scatterometer data over snow covered areas at very large spatial scale in comparison to the range in passive microwave brightness temperatures. Also for the first time, we quantify the improvement on the snow depth retrieval related to the combined use of active and passive data and compare the results with those obtained using either only active or passive data. Finally, we report first results regarding an analysis involving X-band brightness temperatures, collected by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E), aiming at understanding whether the improvements derived from using a combination of active and passive data are related to the use of a low frequency or to the different techniques used (e.g., active or passive). (c) 2007 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA. RSIS, Mclean, VA 22102 USA. RP Tedesco, M (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM mtedesco@umbe.edu RI Tedesco, Marco/F-7986-2015 NR 27 TC 10 Z9 12 U1 3 U2 15 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 EI 1879-0704 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD NOV 30 PY 2007 VL 111 IS 2-3 BP 382 EP 397 DI 10.1016/j.rse.2007.04.019 PG 16 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 234QF UT WOS:000251178000019 ER PT J AU Wang, JR Tedesco, M AF Wang, J. R. Tedesco, M. TI Identification of atmospheric influences on the estimation of snow water equivalent from AMSR-E measurements SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE microwave remote sensing; snow water equivalent; atmospheric correction ID BRIGHTNESS TEMPERATURES; SSM/I DATA; MICROWAVE; RETRIEVAL; DEPTH; ALGORITHM; WINTER; VAPOR; PARAMETERS; MODEL AB Radiometric measurements near 19 and 37 GHz have been used for estimation of snow water equivalent (SWE) for many years. Most conventional SWE retrieval algorithms depend on the difference between the brightness temperatures (T-b's) at these frequencies. The effect of atmospheric absorption is generally assumed to be insignificant, and thus often not taken into account in such estimation. In this paper this effect is closely examined with the aid of AMSR-E and radiosonde data sets over two widely separated regions in the continental U.S.A. Results of the analysis show that even under a clear sky the atmospheric absorption could account for as much as similar to 25-50% to the estimation of SWE. For example, the AMSR-E estimated SWE of 10 cm would become about 13.6 cm when measured at the ground level under the same atmospheric condition; the estimation based on surface emission alone (i.e., no atmosphere) would be about 15.2 cm. There is some regional dependence of this atmospheric absorption effect, but the effect of seasonal variation is negligibly small. Under cloudy conditions, the impact of liquid cloud absorption is significant and it appears necessary to perform either cloud screening or quantify the cloud effects on SWE estimation from 19 to 37 GHz radiometric measurements at ground level or satellite altitudes. Published by Elsevier Inc. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, GEST, Baltimore, MD 21228 USA. RP Wang, JR (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM james.r.wang@nasa.gov RI Tedesco, Marco/F-7986-2015 NR 25 TC 33 Z9 36 U1 1 U2 7 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD NOV 30 PY 2007 VL 111 IS 2-3 BP 398 EP 408 DI 10.1016/j.rse.2006.10.024 PG 11 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 234QF UT WOS:000251178000020 ER PT J AU Odenwald, S AF Odenwald, Sten TI Newspaper reporting of space weather: End of a golden age SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS LA English DT Article AB The reporting of the human impacts of space weather phenomena as a significant American newspaper story has passed through a golden age, which ended just after World War II. Prior to this time, significant geomagnetic storms and solar flare events were reported in considerable detail, with specific references made to actual impacts to telegraph, wireless, and radio communications systems among others. After World War II, news stories shrank dramatically in terms of the size of the article, the location of the story in the newspaper, and the number of items mentioned in the article. This paper is an historical analysis of the scope of newspaper reporting on 52 major storms with AA* > 170 occurring in American newspapers since 1870 and the changing trends in how the events were covered. I will show that even before the advent of news reporting on the World Wide Web, there was a precipitous decline in space weather reporting during the postwar period from ca. 1945-1990. The reason for this decline is not immediately obvious, but a few suggestions will be provided. I also publish 141 excerpts from the newspaper sample highlighting a variety of "human impacts'' caused by this complete sample of storm events, along with a small collection of interesting illustrations that accompanied a few of the articles. C1 Catholic Univ Amer, Washington, DC 20064 USA. [Odenwald, Sten] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Odenwald, S (reprint author), Catholic Univ Amer, Washington, DC 20064 USA. NR 14 TC 2 Z9 2 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1542-7390 J9 SPACE WEATHER JI Space Weather PD NOV 30 PY 2007 VL 5 IS 11 AR S11005 DI 10.1029/2007SW000344 PG 17 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 261KA UT WOS:000253076300001 ER PT J AU Brown, CM Hara, H Kamio, S Feldman, U Seely, JF Doschek, GA Mariska, JT Korendyke, CM Lang, J Dere, KP Culhane, L Thomas, RJ Davila, JM AF Brown, Charles M. Hara, Hirohisa Kamio, Suguru Feldman, Uri Seely, John F. Doschek, George A. Mariska, John T. Korendyke, Clarence M. Lang, James Dere, Kenneth P. Culhane, Len Thomas, Roger J. Davila, Joseph M. TI Wavelength determination for solar features observed by the EUV Imaging spectrometer on Hinode SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN LA English DT Article DE sun; sun : UV radiation ID B SATELLITE AB A wavelength calibration of solar lines observed by the high resolution EUV Imaging Spectrometer (EIS) on the Hinode satellite is reported. Spectral features of the quiet sun and of two mildly active areas were measured and calibrated. A listing of the stronger observed lines with identification of the leading contributor ions is presented. 41 lines are reported, with 90% identified. Wavelength precisions (2 sigma) of +/- 0.0031 A for the EIS short band and ::angstrom 0.0029 A for the EIS long band are obtained. These lines, typical of 1 - 2 x 106 K plasmas, are recommended as standards for the establishment of EIS wavelength scales. The temperature of EIS varies by about 1.degrees 5 C around the orbit and also with spacecraft pointing. The correlation of these temperature changes with wavelength versus pixel number scale changes is reported. C1 [Brown, Charles M.; Seely, John F.; Doschek, George A.; Mariska, John T.; Korendyke, Clarence M.] USN, Res Lab, Div Space Sci, Washington, DC 20375 USA. [Hara, Hirohisa; Kamio, Suguru] Natl Inst Nat Sci, Natl Astron Observ Japan, Mitaka, Tokyo 1818588, Japan. [Feldman, Uri] Artep Inc, Ellicott City, MD 21047 USA. [Lang, James] Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. [Dere, Kenneth P.] George Mason Univ, Fairfax, VA 22020 USA. [Culhane, Len] UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. [Thomas, Roger J.; Davila, Joseph M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Brown, CM (reprint author), USN, Res Lab, Div Space Sci, 4555 Overlook Ave SW, Washington, DC 20375 USA. EM cbrown@ssd5.nrl.navy.mil; hirohisa.hara@nao.ac.jp; suguru.kamio@nao.ac.jp; ufeldman@ssd5.nrl.navy.mil; jseely@ssd5.nrl.navy.mil; gdoschek@ssd5.nrl.navy.mil; mariska@nrl.navy.mil; ckorendyke@ssd5.nrl.navy.mil; J.Lang@rl.ac.uk; kdere@gmu.edu; jlc@mssl.ucl.ac.uk; Roger.J.Thomas@nasa.gov; Joseph.M.Davila@nasa.gov NR 7 TC 20 Z9 20 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0004-6264 EI 2053-051X J9 PUBL ASTRON SOC JPN JI Publ. Astron. Soc. Jpn. PD NOV 30 PY 2007 VL 59 SI 3 BP S865 EP S869 DI 10.1093/pasj/59.sp3.S865 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 262MM UT WOS:000253152600043 ER PT J AU Dere, KP Doschek, GA Mariska, JT Hansteen, VH Harra, LK Matsuzaki, K Thomas, RJ AF Dere, Kenneth P. Doschek, George A. Mariska, John T. Hansteen, Viggo H. Harra, Louise K. Matsuzaki, Keiichi Thomas, Roger J. TI The structure and dynamics of the quiet corona from observations with the Extreme ultraviolet Imaging Spectrometer on Hinode SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN LA English DT Article DE profiles; Sun : corona; Sun : transition region ID ELECTRON-IMPACT EXCITATION; EXPLOSIVE EVENTS; ATOMIC DATABASE; TRANSITION ZONE; EMISSION-LINES; SOLAR; CHIANTI; SUN AB The goal of the Hinode mission is to provide an observational basis for understanding the heating and acceleration of coronal plasmas. On 2007 January 20, the Extreme ultraviolet Imaging Spectrometer performed a raster of a quiet region near Sun center. Maps of intensities, velocities, and electron densities derived from these observations are presented and discussed. Intensity maps in He II lambda 256, formed at 9 x 10(4) K, show the chromospheric network. Line intensities of Fe X-XIV, formed at temperatures from 1-2 x 10(6) K, show small-scale bright points and more extended structures. The intensity map of Fe VIII shows a transition between the two temperatures. The coronal lines reveal regions of high outflow velocities on the order of 100 km s(-1) in a compact region and 12 km s(-1) in an extended region. The presence of such high velocities in the quiet corona is an entirely new and unexpected result. Electron densities derived from density sensitive line ratios of Fe XII and XIII are typically 3-20 x 10(8) cm(-3). The highest densities are found in bright, compact areas. For the first time, explosive events in the quiet sun have been observed in the extreme-ultraviolet in He II lambda 256 profiles. C1 [Dere, Kenneth P.] George Mason Univ, Fairfax, VA 22030 USA. [Doschek, George A.; Mariska, John T.] USN, Res Lab, Div Space Sci, Washington, DC 20375 USA. [Hansteen, Viggo H.] Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. [Harra, Louise K.] UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. [Matsuzaki, Keiichi] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. [Thomas, Roger J.] NASA, Goddard Space Flight Ctr, Solar Phys Lab, Greenbelt, MD 20771 USA. RP Dere, KP (reprint author), George Mason Univ, 4400 Univ Dr, Fairfax, VA 22030 USA. EM kdere@gmu.edu NR 13 TC 12 Z9 12 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0004-6264 EI 2053-051X J9 PUBL ASTRON SOC JPN JI Publ. Astron. Soc. Jpn. PD NOV 30 PY 2007 VL 59 SI 3 BP S721 EP S726 DI 10.1093/pasj/59.sp3.S721 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 262MM UT WOS:000253152600023 ER PT J AU Harra, LK Hara, H Imada, S Young, PR Williams, DR Sterling, AC Korendyke, C Attrill, GDR AF Harra, Louise K. Hara, Hirohisa Imada, Shinsuke Young, Peter R. Williams, David R. Sterling, Alphonse C. Korendyke, Clarence Attrill, Gemma D. R. TI Coronal dimming observed with Hinode: Outflows related to a coronal mass ejection SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN LA English DT Article DE sun : activity; sun : coronal mass ejections; sun : flares; sun : UV radiation ID EIT WAVES; MISSION; REGIONS; EVENT AB Coronal dimming has been a signature used to determine the source of plasma that forms part of a coronal mass ejection (CME) for many years. Generally dimming is detected through imaging instruments such as SOHO EIT by taking difference images. Hinode tracked active region 10930 from which there were a series of flares. We combined dimming observations from EIT with Hinode data to show the impact of flares and coronal mass ejections on the region surrounding the flaring active region, and we discuss evidence that the eruption resulted in a prolonged steady outflow of material from the corona. The dimming region shows clear structure with extended loops whose footpoints are the source of the strongest outflow (approximate to 40 km s(-1)). This confirms that the loops that are disrupted during the event do lose plasma and hence are likely to form part of the CME. This is the first time the velocity of the coronal plasma has been measured in an extended dimming region away from the flare core. In addition there was a weaker steady outflow from extended, faint loops outside the active region before the eruption, which is also long lasting. These were disturbed and the velocity increased following the flare. Such outflows could be the source of the slow solar wind. C1 [Harra, Louise K.; Williams, David R.; Attrill, Gemma D. R.] UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. [Hara, Hirohisa; Imada, Shinsuke] Natl Inst Nat Sci, Natl Astron Observ Japan, Mitaka, Tokyo 1818588, Japan. [Young, Peter R.] Rutherford Appleton Lab, STFC, Didcot OX11 0QX, Oxon, England. [Sterling, Alphonse C.] NASA, George C Marshall Space Flight Ctr, Space Sci Off VP62, Huntsville, AL 35812 USA. [Korendyke, Clarence] USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Harra, LK (reprint author), UCL, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England. EM lkh@mssl.ucl.ac.uk RI Williams, David/E-6676-2011 OI Williams, David/0000-0001-9922-8117 NR 20 TC 53 Z9 54 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0004-6264 EI 2053-051X J9 PUBL ASTRON SOC JPN JI Publ. Astron. Soc. Jpn. PD NOV 30 PY 2007 VL 59 SI 3 BP S801 EP S806 DI 10.1093/pasj/59.sp3.S801 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 262MM UT WOS:000253152600034 ER PT J AU Sterling, AC Moore, RL Berger, TE Bobra, M Davis, JM Jibben, P Kano, R Lundquist, LL Myers, D Narukage, N Sakao, T Shibasaki, K Shine, RA Tarbell, TD Weber, M AF Sterling, Alphonse C. Moore, Ronald L. Berger, Thomas E. Bobra, Monica Davis, John M. Jibben, Patricia Kano, Ryohei Lundquist, Loraine L. Myers, D. Narukage, Noriyuki Sakao, Taro Shibasaki, Kiyoto Shine, Richard A. Tarbell, Theodore D. Weber, Mark TI Hinode observations of the onset stage of a solar filament eruption SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN LA English DT Article DE sun : filaments; sun : flares; sun : UV radiation; sun : x-rays, gamma rays ID CORONAL MASS EJECTIONS; FLARES; RECONNECTION; MISSION; CME AB We used Hinode X-Ray Telescope (XRT) and Solar Optical Telescope (SOT) filtergraph (FG) Stokes-V magnetogram observations, to study the early onset of a solar eruption that includes an erupting filament that we observe in TRACE EUV images. The filament undergoes a slow rise for at least 20min prior to its fast eruption and strong soft X-ray (SXR) flaring; such slow rises have been previously reported, and the new Hinode data elucidate the physical processes occurring during this period. XRT images show that during the slow-rise phase, an SXR sigmoid forms from apparent reconnection low in the sheared core field traced by the filament, and there is a low-level intensity peak in both EUV and SXRs during the slow rise. MDI and SOT FG Stokes-V magnetograms show that the pre-eruption filament is along a neutral line between opposing-polarity enhanced network cells, and the SOT magnetograms show that these opposing fields are flowing together and canceling for at least six hours prior to eruption. From the MDI data we measured the canceling network fields to be similar to 40 G, and we estimated that similar to 10(19) Mx of flux canceled during the five hours prior to eruption; this is only similar to 5% of the total flux spanned by the eruption and flare, but apparently its tether-cutting cancellation was enough to destabilize the sigmoid field holding the filament and resulted in that field's eruption. C1 [Sterling, Alphonse C.; Moore, Ronald L.; Davis, John M.] NASA, George C Marshall Space Flight Ctr, Space Sci Off VP62, Huntsville, AL 35805 USA. [Sterling, Alphonse C.; Narukage, Noriyuki; Sakao, Taro] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. [Berger, Thomas E.; Shine, Richard A.; Tarbell, Theodore D.] Lockheed Palo Alto Res Labs, Palo Alto, CA 94304 USA. [Bobra, Monica; Jibben, Patricia; Lundquist, Loraine L.; Weber, Mark] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Kano, Ryohei] Natl Inst Nat Sci, Natl Astron Observ Japan, Mitaka, Tokyo 1818588, Japan. [Myers, D.] Adnet Syst Inc, Rockville, MD 20852 USA. [Shibasaki, Kiyoto] Natl Inst Nat Sci, Natl Astron Observ Japan, Nobeyama Radio Observ, Minamimaki, Nagano 3841305, Japan. RP Sterling, AC (reprint author), NASA, George C Marshall Space Flight Ctr, Space Sci Off VP62, Huntsville, AL 35805 USA. EM asterling@spd.aas.org NR 26 TC 20 Z9 20 U1 2 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0004-6264 EI 2053-051X J9 PUBL ASTRON SOC JPN JI Publ. Astron. Soc. Jpn. PD NOV 30 PY 2007 VL 59 SI 3 BP S823 EP S829 DI 10.1093/pasj/59.sp3.S823 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 262MM UT WOS:000253152600037 ER PT J AU Boardsen, SA Slavin, JA AF Boardsen, S. A. Slavin, J. A. TI Search for pick-up ion generated Na+ cyclotron waves at Mercury SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAGNETOSPHERE; SODIUM; EXOSPHERE; MODEL AB [1] Magnetometer data was examined from the two Mariner 10 passages through Mercury's magnetosphere for evidence of Na+ electromagnetic ion cyclotron waves ( ICW). These waves are expected to be produced if the thermalization of newly created Na+ 5pick- up ions occurs. We found no evidence of Na+ ICW. The spacecraft's rapid passage through Mercury's magnetosphere meant that the ambient magnetic field was only relatively constant for at most similar to 3 - 4 Na+ ICW wave periods throughout each transversal, therefore limiting the spectral resolution of the Na+ cyclotron frequency. Our computations indicate that the wavelengths of Na+ ICW may be on the order of the system scale lengths. It is, therefore, questionable whether these waves can grow to sufficient amplitude to effectively thermalize these pick- up ions and incorporate them into Mercury's magnetosphere. C1 Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Heliophys Sci Div, Greenbelt, MD 20771 USA. RP Boardsen, SA (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol, 5523 Res Pk Dr, Baltimore, MD 21228 USA. EM scott.a.boardsen@nasa.gov RI Slavin, James/H-3170-2012 OI Slavin, James/0000-0002-9206-724X NR 21 TC 11 Z9 11 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 29 PY 2007 VL 34 IS 22 AR L22106 DI 10.1029/2007GL031504 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 237AO UT WOS:000251345100004 ER PT J AU Yang, K Krotkov, NA Krueger, AJ Carn, SA Bhartia, PK Levelt, PF AF Yang, Kai Krotkov, Nickolay A. Krueger, Arlin J. Carn, Simon A. Bhartia, Pawan K. Levelt, Pieternel F. TI Retrieval of large volcanic SO2 columns from the Aura Ozone Monitoring Instrument: Comparison and limitations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ROTATIONAL RAMAN-SCATTERING; ABSORPTION CROSS-SECTIONS; SULFUR-DIOXIDE; MAPPING SPECTROMETER; RADIATIVE-TRANSFER; UV SPECTROSCOPY; ASH CLOUDS; GOME; SCIAMACHY; MODEL AB To improve global measurements of atmospheric sulfur dioxide (SO2), we have developed a new technique, called the linear fit (LF) algorithm, which uses the radiance measurements from the Ozone Monitoring Instrument (OMI) at a few discrete ultraviolet wavelengths to derive SO2, ozone, and effective reflectivity simultaneously. We have also developed a sliding median residual correction method for removing both the along- and cross-track biases from the retrieval results. The achieved internal consistencies among the LF-retrieved geophysical parameters clearly demonstrate the success of this technique. Comparison with the results from the Band Residual Difference technique has also illustrated the drastic improvements of this new technique at high SO2 loading conditions. We have constructed an error equation and derived the averaging kernel to characterize the LF retrieval and understand its limitations. Detailed error analysis has focused on the impacts of the SO2 column amounts and their vertical distributions on the retrieval results. The LF algorithm is robust and fast; therefore it is suitable for near real-time application in aviation hazards and volcanic eruption warnings. Very large SO2 loadings (>100 DU) require an off-line iterative solution of the LF equations to reduce the retrieval errors. Both the LF and sliding median techniques are very general so that they can be applied to measurements from other backscattered ultraviolet instruments, including the series of Total Ozone Mapping Spectrometer (TOMS) missions, thereby offering the capability to update the TOMS long-term record to maintain consistency with its OMI extension. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. Royal Dutch Meteorol Inst, NL-3730 AE De Bilt, Netherlands. RP Yang, K (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 613 3, Greenbelt, MD 20771 USA. EM kai.yang-1@nasa.gov RI Krotkov, Nickolay/E-1541-2012; Bhartia, Pawan/A-4209-2016 OI Krotkov, Nickolay/0000-0001-6170-6750; Bhartia, Pawan/0000-0001-8307-9137 NR 53 TC 108 Z9 113 U1 2 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 29 PY 2007 VL 112 IS D24 AR D24S43 DI 10.1029/2007JD008825 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 237BC UT WOS:000251346600001 ER PT J AU Piccioni, G Drossart, P Sanchez-Lavega, A Hueso, R Taylor, FW Wilson, CF Grassi, D Zasova, L Moriconi, M Adriani, A Lebonnois, S Coradini, A Bezard, B Angrilli, F Arnold, G Baines, KH Bellucci, G Benkhoff, J Bibring, JP Blanco, A Blecka, MI Carlson, RW Di Lellis, A Encrenaz, T Erard, S Fonti, S Formisano, V Fouchet, T Garcia, R Haus, R Helbert, J Ignatiev, NI Irwin, PGJ Langevin, Y Lopez-Valverde, MA Luz, D Marinangeli, L Orofino, V Rodin, AV Roos-Serote, MC Saggin, B Stam, DM Titov, D Visconti, G Zambelli, M AF Piccioni, G. Drossart, P. Sanchez-Lavega, A. Hueso, R. Taylor, F. W. Wilson, C. F. Grassi, D. Zasova, L. Moriconi, M. Adriani, A. Lebonnois, S. Coradini, A. Bezard, B. Angrilli, F. Arnold, G. Baines, K. H. Bellucci, G. Benkhoff, J. Bibring, J. P. Blanco, A. Blecka, M. I. Carlson, R. W. Di Lellis, A. Encrenaz, T. Erard, S. Fonti, S. Formisano, V. Fouchet, T. Garcia, R. Haus, R. Helbert, J. Ignatiev, N. I. Irwin, P. G. J. Langevin, Y. Lopez-Valverde, M. A. Luz, D. Marinangeli, L. Orofino, V. Rodin, A. V. Roos-Serote, M. C. Saggin, B. Stam, D. M. Titov, D. Visconti, G. Zambelli, M. CA VIRTIS-Venis Express Tech Te TI South-polar features on Venus similar to those near the North Pole SO NATURE LA English DT Article ID CLOUD STRUCTURE; PIONEER ORBITER; NIGHT-SIDE; ATMOSPHERE; SPECTRA AB Venus has no seasons, slow rotation and a very massive atmosphere, which is mainly carbon dioxide with clouds primarily of sulphuric acid droplets. Infrared observations by previous missions to Venus revealed a bright 'dipole' feature surrounded by a cold 'collar' at its north pole(1-4). The polar dipole is a 'double-eye' feature at the centre of a vast vortex that rotates around the pole, and is possibly associated with rapid downwelling. The polar cold collar is a wide, shallow river of cold air that circulates around the polar vortex. One outstanding question has been whether the global circulation was symmetric, such that a dipole feature existed at the south pole. Here we report observations of Venus' south-polar region, where we have seen clouds with morphology much like those around the north pole, but rotating somewhat faster than the northern dipole. The vortex may extend down to the lower cloud layers that lie at about 50 km height and perhaps deeper. The spectroscopic properties of the clouds around the south pole are compatible with a sulphuric acid composition. C1 INAF IASF, Ist Astrofis Spaziale & Fis Cosm, I-00133 Rome, Italy. CNR, ISAC, I-00133 Rome, Italy. INAF IFSI, I-00133 Rome, Italy. Univ Paris Diderot, UPMC, Observ Paris, LESIA, F-92195 Meudon, France. Univ Basque Country, Escuela Super Ingn, Dept Fis Aplicada 1, Bilbao 48013, Spain. Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Russian Acad Sci, Inst Space Res, Moscow 117997, Russia. Meteorol Dynam Lab, F-75252 Paris 05, France. Univ Padua, CISAS, I-35131 Padua, Italy. German Aerosp Ctr, DLR, Inst Planetary Explorat, Planetary Phys Sect, D-12489 Berlin, Germany. Jet Propuls Lab, Pasadena, CA 91011 USA. Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. Univ Lecce, Dipartimento Fis, I-73100 Lecce, Italy. Polish Acad Sci, Space Res Ctr, PL-00716 Warsaw, Poland. AMDLSPACE srl, I-00149 Rome, Italy. Inst Phys Globe Paris, Dept Etud Spatiales, F-94107 St Maur des Fosses, France. CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain. Univ G DAnnunzio, Dipartimento Sci, Int Res Sch Planetary Sci, I-65127 Pescara, Italy. Univ Nova Lisboa, Ctr Astron & Astrofis, Observ Astron Lisboa, P-1349018 Lisbon, Portugal. Politecn Milan, I-23900 Lecce, Italy. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. Univ Aquila, Dipartimento Fis, I-67010 Laquila, Italy. RP Piccioni, G (reprint author), INAF IASF, Ist Astrofis Spaziale & Fis Cosm, Via Fosso Cavaliere 100, I-00133 Rome, Italy. EM Giuseppe.piccioni@iasf-roma.inaf.it RI Garcia, Raphael/B-2612-2012; moriconi, maria luisa/B-7201-2009; Luz, David/J-4588-2013; Rodin, Alexander/L-1904-2013; Fouchet, Thierry/C-6374-2017; OI Sanchez-Lavega, Agustin/0000-0001-7355-1522; Filacchione, Gianrico/0000-0001-9567-0055; LEBONNOIS, SEBASTIEN/0000-0002-2390-8164; Irwin, Patrick/0000-0002-6772-384X; Lopez-Valverde, M. A./0000-0002-7989-4267; Piccioni, Giuseppe/0000-0002-7893-6808; Hueso, Ricardo/0000-0003-0169-123X; saggin, bortolino/0000-0002-4033-3585; Tosi, Federico/0000-0003-4002-2434; moriconi, maria luisa/0000-0003-2609-2620; Adriani, Alberto/0000-0003-4998-8008; Luz, David/0000-0002-9473-8035; Rodin, Alexander/0000-0002-3601-7790; Fouchet, Thierry/0000-0001-9040-8285; Helbert, Jorn/0000-0001-5346-9505; Bellucci, Giancarlo/0000-0003-0867-8679; Capaccioni, Fabrizio/0000-0003-1631-4314 NR 19 TC 68 Z9 68 U1 1 U2 18 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD NOV 29 PY 2007 VL 450 IS 7170 BP 637 EP 640 DI 10.1038/nature06209 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 235BY UT WOS:000251209700035 PM 18046395 ER PT J AU Drossart, P Piccioni, G Gerard, JC Lopez-Valverde, MA Sanchez-Lavega, A Zasova, L Hueso, R Taylor, FW Bezard, B Adriani, A Angrilli, F Arnold, G Baines, KH Bellucci, G Benkhoff, J Bibring, JP Blanco, A Blecka, MI Carlson, RW Coradini, A Di Lellis, A Encrenaz, T Erard, S Fonti, S Formisano, V Fouchet, T Garcia, R Haus, R Helbert, J Ignatiev, NI Irwin, P Langevin, Y Lebonnois, S Luz, D Marinangeli, L Orofino, V Rodin, AV Roos-Serote, MC Saggin, B Stam, DM Titov, D Visconti, G Zambelli, M Tsang, C AF Drossart, P. Piccioni, G. Gerard, J. C. Lopez-Valverde, M. A. Sanchez-Lavega, A. Zasova, L. Hueso, R. Taylor, F. W. Bezard, B. Adriani, A. Angrilli, F. Arnold, G. Baines, K. H. Bellucci, G. Benkhoff, J. Bibring, J. P. Blanco, A. Blecka, M. I. Carlson, R. W. Coradini, A. Di Lellis, A. Encrenaz, T. Erard, S. Fonti, S. Formisano, V. Fouchet, T. Garcia, R. Haus, R. Helbert, J. Ignatiev, N. I. Irwin, P. Langevin, Y. Lebonnois, S. Luz, D. Marinangeli, L. Orofino, V. Rodin, A. V. Roos-Serote, M. C. Saggin, B. Stam, D. M. Titov, D. Visconti, G. Zambelli, M. Tsang, C. CA VIRTIS-Venus Express Tech Te TI A dynamic upper atmosphere of Venus as revealed by VIRTIS on Venus Express SO NATURE LA English DT Article ID INFRARED EMISSIONS; AIRGLOW; MARS AB The upper atmosphere of a planet is a transition region in which energy is transferred between the deeper atmosphere and outer space. Molecular emissions from the upper atmosphere (90-120 km altitude) of Venus can be used to investigate the energetics and to trace the circulation of this hitherto little-studied region. Previous spacecraft(1) and ground-based(2-4) observations of infrared emission from CO2, O-2 and NO have established that photochemical and dynamic activity controls the structure of the upper atmosphere of Venus. These data, however, have left unresolved the precise altitude of the emission(1) owing to a lack of data and of an adequate observing geometry(5,6). Here we report measurements of day-side CO2 non-local thermodynamic equilibrium emission at 4.3 mu m, extending from 90 to 120 km altitude, and of night-side O-2 emission extending from 95 to 100 km. The CO2 emission peak occurs at similar to 115 km and varies with solar zenith angle over a range of similar to 10 km. This confirms previous modelling(7), and permits the beginning of a systematic study of the variability of the emission. The O-2 peak emission happens at 96 km +/- 1 km, which is consistent with three-body recombination of oxygen atoms transported from the day side by a global thermospheric sub-solar to anti-solar circulation, as previously predicted(8). C1 Univ Paris Diderot, UPMC, CNRS, Observ Paris,LESIA, F-92195 Meudon, France. INAF IASF, I-00133 Rome, Italy. INAF IFSI, I-00133 Rome, Italy. Univ Liege, LPAP, B-4000 Liege, Belgium. CSIC, Inst Astrofis Andalucia, E-18008 Granada, Spain. Univ Basque Country, Escuela Super Ingn Fis Aplicada 1, Bilbao 48013, Spain. Space Res Inst, IKI, Moscow, Russia. Clarendon Lab, Oxford OX1 3PU, England. Univ Padua, CISAS, I-35131 Padua, Italy. German Aerosp Ctr, DLR, D-12489 Berlin, Germany. Jet Propuls Lab, Pasadena, CA 91109 USA. Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. Univ Lecce, Dipartimento Fis, I-73100 Lecce, Italy. Ctr Badan Kosmicznych Pan, PL-00716 Warsaw, Poland. AMDLSPACE, I-00149 Rome, Italy. Observ Midi Pyrenees, CNRS, UMR5562, F-31400 Toulouse, France. UPMC, Meteorol Dynam Lab, F-75252 Paris 05, France. Univ G DAnnunzio, I-65127 Pescara, Italy. Lisbon Astron Observ, P-1349018 Lisbon, Portugal. Politecn Milan, I-20133 Milan, Italy. Univ Amsterdam, NL-1098 SJ Amsterdam, Netherlands. Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. Univ Aquila, Dipartimento Fis, I-67010 Laquila, Italy. RP Drossart, P (reprint author), Univ Paris Diderot, UPMC, CNRS, Observ Paris,LESIA, 5 Pl Jules Janssen, F-92195 Meudon, France. RI Garcia, Raphael/B-2612-2012; Luz, David/J-4588-2013; Rodin, Alexander/L-1904-2013; Fouchet, Thierry/C-6374-2017; OI Filacchione, Gianrico/0000-0001-9567-0055; LEBONNOIS, SEBASTIEN/0000-0002-2390-8164; Irwin, Patrick/0000-0002-6772-384X; Lopez-Valverde, M. A./0000-0002-7989-4267; Piccioni, Giuseppe/0000-0002-7893-6808; Hueso, Ricardo/0000-0003-0169-123X; saggin, bortolino/0000-0002-4033-3585; Tosi, Federico/0000-0003-4002-2434; GERARD, Jean-Claude/0000-0002-8565-8746; Bellucci, Giancarlo/0000-0003-0867-8679; Capaccioni, Fabrizio/0000-0003-1631-4314; Adriani, Alberto/0000-0003-4998-8008; Sanchez-Lavega, Agustin/0000-0001-7355-1522; Luz, David/0000-0002-9473-8035; Rodin, Alexander/0000-0002-3601-7790; Fouchet, Thierry/0000-0001-9040-8285; Helbert, Jorn/0000-0001-5346-9505 NR 15 TC 61 Z9 61 U1 1 U2 23 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD NOV 29 PY 2007 VL 450 IS 7170 BP 641 EP 645 DI 10.1038/nature06140 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 235BY UT WOS:000251209700036 PM 18046396 ER PT J AU Patzold, M Hausler, B Bird, MK Tellmann, S Mattei, R Asmar, SW Dehant, V Eidel, W Imamura, T Simpson, RA Tyler, GL AF Paetzold, M. Haeusler, B. Bird, M. K. Tellmann, S. Mattei, R. Asmar, S. W. Dehant, V. Eidel, W. Imamura, T. Simpson, R. A. Tyler, G. L. TI The structure of Venus' middle atmosphere and ionosphere SO NATURE LA English DT Article ID RADIO OCCULTATION; SOLAR-CYCLE; SPACECRAFT AB The atmosphere and ionosphere of Venus have been studied in the past by spacecraft with remote sensing(1-4) or in situ techniques(3,4). These early missions, however, have left us with questions about, for example, the atmospheric structure in the transition region from the upper troposphere to the lower mesosphere (50-90 km) and the remarkably variable structure of the ionosphere. Observations become increasingly difficult within and below the global cloud deck (<50 km altitude), where strong absorption greatly limits the available investigative spectrum to a few infrared windows and the radio range. Here we report radio-sounding results from the first Venus Express Radio Science(5) (VeRa) occultation season. We determine the fine structure in temperatures at upper cloud-deck altitudes, detect a distinct day-night temperature difference in the southern middle atmosphere, and track day-to-day changes in Venus' ionosphere. C1 Univ Cologne, Rhein Inst Umweltforsch, Abt Planetenforsch, D-50931 Cologne, Germany. Univ Bundeswehr Munchen, Inst Raumfahrttech, D-85577 Neubiberg, Germany. Argelander Inst Astron, D-53121 Bonn, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Observ Royal Belgique, B-1180 Brussels, Belgium. Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa, Japan. Stanford Univ, Space Telecommun & Radiosci Lab, Stanford, CA 94305 USA. RP Patzold, M (reprint author), Univ Cologne, Rhein Inst Umweltforsch, Abt Planetenforsch, Aachener Str 201-209, D-50931 Cologne, Germany. EM paetzold@geo.uni-koeln.de NR 14 TC 56 Z9 57 U1 1 U2 15 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 29 PY 2007 VL 450 IS 7170 BP 657 EP 660 DI 10.1038/nature06239 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 235BY UT WOS:000251209700040 PM 18046400 ER PT J AU Coates, AJ Crary, FJ Lewis, GR Young, DT Waite, JH Sittler, EC AF Coates, A. J. Crary, F. J. Lewis, G. R. Young, D. T. Waite, J. H., Jr. Sittler, E. C., Jr. TI Discovery of heavy negative ions in Titan's ionosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CASSINI PLASMA SPECTROMETER; ELECTRON-AFFINITY; PHOTOELECTRON-SPECTROSCOPY; ATMOSPHERE AB Titan's ionosphere contains a rich positive ion population including organic molecules. Here, using CAPS electron spectrometer data from sixteen Titan encounters, we reveal the existence of negative ions. These ions, with densities up to similar to 100 cm similar to 3, are in mass groups of 10-30, 30-50, 50-80, 80-110, 110-200 and 200+ amu/charge. During one low encounter, negative ions with mass per charge as high as 10,000 amu/q are seen. Due to their unexpectedly high densities at similar to 950 km altitude, these negative ions must play a key role in the ion chemistry and they may be important in the formation of organic-rich aerosols (tholins) eventually falling to the surface. C1 UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. SW Res Inst, Space Sci & Engn Div, San Antonio, TX 78238 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Coates, AJ (reprint author), UCL, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England. EM ajc@mssl.ucl.ac.uk RI Coates, Andrew/C-2396-2008 OI Coates, Andrew/0000-0002-6185-3125 FU Science and Technology Facilities Council [PP/D00084X/1] NR 33 TC 189 Z9 189 U1 2 U2 22 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 28 PY 2007 VL 34 IS 22 AR L22103 DI 10.1029/2007GL030978 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 237AN UT WOS:000251345000001 ER PT J AU Fischer, G Gurnett, DA Kurth, WS Farrell, WM Kaiser, ML Zarka, P AF Fischer, G. Gurnett, D. A. Kurth, W. S. Farrell, W. M. Kaiser, M. L. Zarka, P. TI Nondetection of Titan lightning radio emissions with Cassini/RPWS after 35 close Titan flybys SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PHYSICAL-CHARACTERISTICS; ATMOSPHERE; CLOUDS; HYDROCARBONS; DISSIPATION; GENERATION; IONOSPHERE; DISCHARGE; EVOLUTION; SURFACE AB We report on the nondetection of radio emissions associated with possible lightning flashes in Titan's atmosphere by the Cassini/RPWS ( Radio and Plasma Wave Science) instrument. A valid proof for Titan lightning would be the detection of a number of bursty radio signals above Titan's ionospheric cutoff frequency, and they should be grouped near the closest approach of Cassini to Titan with an approximately quadratic fall off of signal intensity with spacecraft distance. Such a clear signature has not been detected by the RPWS instrument during the first 35 close flybys of Titan. C1 Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Observ Paris, Paris, France. RP Fischer, G (reprint author), Univ Iowa, Dept Phys & Astron, 203 Van Allen Hall, Iowa City, IA 52242 USA. EM georg-fischer@uiowa.edu RI Farrell, William/I-4865-2013; OI Kurth, William/0000-0002-5471-6202 NR 36 TC 14 Z9 14 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 28 PY 2007 VL 34 IS 22 AR L22104 DI 10.1029/2007GL031668 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 237AN UT WOS:000251345000004 ER PT J AU Jacobs, BW Ayres, VM Stallcup, RE Hartman, A Tupta, MA Baczewski, AD Crimp, MA Halpern, JB He, M Shaw, HC AF Jacobs, B. W. Ayres, V. M. Stallcup, R. E. Hartman, A. Tupta, M. A. Baczewski, A. D. Crimp, M. A. Halpern, J. B. He, M. Shaw, H. C. TI Electron transport in zinc-blende wurtzite biphasic gallium nitride nanowires and GaNFETs SO NANOTECHNOLOGY LA English DT Article ID GAN NANOWIRES; GROWTH; NANODEVICES; FABRICATION; NH3 AB Two-point and four-point probe electrical measurements of a biphasic gallium nitride nanowire and current-voltage characteristics of a gallium nitride nanowire based field effect transistor are reported. The biphasic gallium nitride nanowires have a crystalline homostructure consisting of wurtzite and zinc-blende phases that grow simultaneously in the longitudinal direction. There is a sharp transition of one to a few atomic layers between each phase. All measurements showed high current densities. Evidence of single-phase current transport in the biphasic nanowire structure is discussed. C1 Michigan State Univ, E Lansing, MI 48824 USA. Zyvex Instruments, Richardson, TX 75081 USA. Keithley Instruments Inc, Cleveland, OH 44139 USA. Howard Univ, Washington, DC 20059 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Jacobs, BW (reprint author), Michigan State Univ, E Lansing, MI 48824 USA. OI Halpern, Joshua/0000-0002-8086-2617 NR 27 TC 6 Z9 6 U1 0 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD NOV 28 PY 2007 VL 18 IS 47 AR 475710 DI 10.1088/0957-4484/18/47/475710 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 228JF UT WOS:000250725500029 ER PT J AU Taktakishvili, A Kuznetsova, M Hesse, M Rastaetter, L Chulaki, A Pulkkinen, A AF Taktakishvili, A. Kuznetsova, M. Hesse, M. Rastaetter, L. Chulaki, A. Pulkkinen, A. TI Metrics analysis of the coupled Block Adaptive-Tree Solar Wind Roe-Type Upwind Scheme and Fok ring current model performance SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS LA English DT Article ID DECAY; EARTH AB Modeling is an important tool in understanding physical processes in the solar system. Metrics analysis evaluates model performance by comparing model output to a measurable parameter of interest. In this paper we studied the performance of the coupled Block Adaptive-Tree Solar Wind Roe-Type Upwind Scheme (BATSRUS) global magnetosphere MHD code and the Fok ring current model (FRC) by examining in detail the geosynchronous proton fluxes during the injection event on 21-22 January 2005. The output of BATSRUS code, calculated ionospheric potential and magnetic field, as well as proton temperature and density distribution, is used as an input boundary condition for the FRC model. We also discuss another event, on 10-11 August 2000, and speculate about the reasons of an apparent difference in the performance of the coupled models for these two events. The results of the simulation are compared with two LANL satellite observations, LANL-97A and 1994-084. The comparison of the simulation results for strongly varying solar wind and for prolonged interval of steady solar wind with southward IMF B(z), demonstrates that coupled BATSRUS and FRC models perform fairly for the magnetosphere driven by strong solar wind disturbances and probably are missing some internal magnetosphere dynamics in the second case. C1 [Taktakishvili, A.; Kuznetsova, M.; Hesse, M.; Rastaetter, L.; Chulaki, A.; Pulkkinen, A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Taktakishvili, A (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM staktak@helio.gsfc.nasa.gov RI Rastaetter, Lutz/D-4715-2012; Kuznetsova, Maria/F-6840-2012 OI Rastaetter, Lutz/0000-0002-7343-4147; NR 16 TC 5 Z9 5 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1542-7390 J9 SPACE WEATHER JI Space Weather PD NOV 28 PY 2007 VL 5 IS 11 AR S11004 DI 10.1029/2007SW000321 PG 10 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 261JY UT WOS:000253076100001 ER PT J AU Connor, BJ Mooney, T Barrett, J Solomon, P Parrish, A Santee, M AF Connor, Brian J. Mooney, Thomas Barrett, James Solomon, Philip Parrish, Alan Santee, Michelle TI Comparison of ClO measurements from the Aura Microwave Limb Sounder to ground-based microwave measurements at Scott Base, Antarctica, in spring 2005 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHLORINE MONOXIDE; LOW ALTITUDES; OZONE; STRATOSPHERE; CHEMISTRY; VORTEX; MODEL; CIO AB We have examined measurements of chlorine monoxide, ClO, in the lower stratosphere by the Microwave Limb Sounder (MLS) on the Aura satellite in the austral spring of 2005. These measurements have been compared to those of a ground-based spectrometer at Scott Base, Antarctica. The data analysis is performed in both cases by subtracting nighttime measurements from daytime ones. The transition from full darkness to full daylight at the high latitude of Scott Base limits the time during which both day and night measurements are made. After further selection for good observing conditions and the position of the polar vortex, 16 valid profile comparisons are made. The day-to-day variability of ClO is observed to be large, similar to 30% of its peak value. The daily column densities of the two instruments are correlated with a significance of 3 sigma with most of the mean difference arising from 2 days. The statistical agreement between MLS and the Scott Base instrument is good. Scott Base values are on average marginally but not significantly larger, by 0.10 +/- 0.07 ppb, or 11 +/- 8% (1 sigma), in peak mixing ratio, than the MLS values. C1 Natl Inst Water & Atmospher Res, Lauder, New Zealand. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Univ Massachusetts, Dept Phys & Astron, Amherst, MA 01003 USA. Jet Propuls Lab, Pasadena, CA USA. RP Connor, BJ (reprint author), Natl Inst Water & Atmospher Res, Private Bag 50061, Lauder, New Zealand. EM b.connor@niwa.co.nz NR 19 TC 11 Z9 11 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 27 PY 2007 VL 112 IS D24 AR D24S42 DI 10.1029/2007JD008792 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 237BB UT WOS:000251346500001 ER PT J AU Podesta, JJ AF Podesta, J. J. TI Self-similar scaling of kinetic energy density in the inertial range of solar wind turbulence SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HIGH-REYNOLDS-NUMBER; INTERMITTENT TURBULENCE; VELOCITY FLUCTUATIONS; FRACTIONAL DYNAMICS; ANOMALOUS DIFFUSION; TRANSPORT; MEDIA AB Probability density functions (pdfs) for time-delayed differences of the solar wind proton density n(p) are shown to be approximately self-similar over the range of timescales from similar to 90 to 1100 s with an approximate scaling exponent gamma = 0.274. The density pdfs are found not to be self-similar over the expanded range of timescales from 90 to 10(4) s in the spacecraft frame. Pdfs for time-delayed differences of the kinetic energy density rho V(2) are found not to be self-similar over either of these two time ranges. The observed self-similar scaling of the proton density is important because it implies that the nonlinear evolution of this quantity in the inertial range of the turbulence is devoid of intermittency effects. These conclusions are based on the analysis of 10 years ( a) of data from the Solar Wind Experiment on board the Wind spacecraft covering the time period from 1995 to 2004 and containing approximately 2.5 x 10(6) data points. Two types of analyses are performed. First, a graphical analysis is used to see whether the rescaled pdfs all lie on a common curve. Then, an analysis of low-order structure functions is performed to see if the scaling properties of the structure functions are consistent with self-similar scaling. Ideally, the results of the pdf scaling analysis and the structure function analysis should both produce the same value of the scaling exponent. Because structure functions are influenced by the presence of outliers in the data, special analysis techniques have to be used to extract the scaling behavior. The special techniques employed here are found to be of limited practical utility because of difficulties in obtaining demonstrable convergence of the scaling exponents. C1 NASA Goddard Space Flight Ctr, Lab Solar & Space Phys, Greenbelt, MD 20771 USA. RP Podesta, JJ (reprint author), NASA Goddard Space Flight Ctr, Lab Solar & Space Phys, Code 612 2, Greenbelt, MD 20771 USA. EM jpodesta@solar.stanford.edu NR 43 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 27 PY 2007 VL 112 IS A11 AR A11104 DI 10.1029/2007JA012549 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 237BW UT WOS:000251348800003 ER PT J AU Panda, J AF Panda, J. TI Experimental investigation of turbulent density fluctuations and noise generation from heated jets SO JOURNAL OF FLUID MECHANICS LA English DT Article ID HIGH-SPEED JETS; MIXING NOISE; SCALING LAWS; TEMPERATURE; FLOW; HOT AB Low-frequency noise sources in heated single-stream jets were identified by cross-correlating turbulent density fluctuations p ' with the far-field sound pressure fluctuations p. The turbulent density fluctuations were measured by a molecular Rayleigh-scattering technique. For a fixed jet velocity U(j), the normalized correlation coefficient < p '; p '>/(p '(rms) p '(rms)) is found to increase progressively with an increase in the plume temperature (subscript rms stands for root-mean-square). The result indicates an improvement of the noise radiation efficiency with heating. Directly measured noise spectra from fixed velocity jets with increasing temperature ratio show confusing trends. However, if such spectra are normalized by the plume density, then a consistent trend of increasing noise level with increased plume temperature emerges. The increased noise is the most prominent at the low-frequency end, consistent with the correlation data. The effect of increasing jet velocity keeping the plume temperature constant was also studied. The correlation coefficients were found to improve significantly with velocity; a result consistent with prior observation from unheated jets. Additional findings on the time-averaged density variations and the changes in the air density fluctuations with increasing plume temperature are also discussed. C1 NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. RP Panda, J (reprint author), NASA, Glenn Res Ctr, Ohio Aerosp Inst, Brookpk, Cleveland, OH 44135 USA. NR 30 TC 8 Z9 8 U1 0 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD NOV 25 PY 2007 VL 591 BP 73 EP 96 DI 10.1017/S0022112007007173 PG 24 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 238UZ UT WOS:000251474500004 ER EF