Search

Your search keyword '"Kahn, Steven M."' showing total 183 results
Start Over Author "Kahn, Steven M."
183 results on '"Kahn, Steven M."'

152. Evidence for the Importance of Resonance Scattering in X-Ray Emission Line Profiles of the O Star ? Puppis

Author

Leutenegger, Maurice A., Owocki, Stanley P., Kahn, Steven M., and S, Frits B.

Abstract

We fit the Doppler profiles of the He-like triplet complexes of O VII and N VI in the X-ray spectrum of the O star z Pup, using XMM-Newton RGS data collected over ~400 ks of exposure. We find that they cannot be well fit if the resonance and intercombination lines are constrained to have the same profile shape. However, a significantly better fit is achieved with a model incorporating the effects of resonance scattering, which causes the resonance line to become more symmetric than the intercombination line for a given characteristic continuum optical depth t*. We discuss the plausibility of this hypothesis, as well as its significance for our understanding of Doppler profiles of X-ray emission lines in O stars.

Published
2007

153. Laboratory Measurement and Theoretical Modeling of K-Shell X-Ray Lines from Inner-Shell Excited and Ionized Ions of Oxygen

Author

Feng, Ming, Schmidt, Mike, Beiersdorfer, Peter, Chen, Hui, Thorn, Daniel B., Trabert, Elmar, Behar, Ehud, and Kahn, Steven M.

Abstract

We present high-resolution laboratory spectra of K-shell X-ray lines from inner-shell excited and ionized ions of oxygen, obtained with a reflection grating spectrometer on the electron beam ion trap (EBIT-I) at the Lawrence Livermore National Laboratory. Only with a multi-ion model including all major atomic collisional and radiative processes are we able to identify the observed K-shell transitions of oxygen ions from O III to O VI. The wavelengths and associated errors for some of the strongest transitions are given, taking into account both the experimental and modeling uncertainties. The present data should be useful in identifying the absorption features present in astrophysical sources, such as active galactic nuclei and X-ray binaries. They are also useful in providing benchmarks for the testing of theoretical atomic structure calculations.

Published
2005

154. Can a Dusty Warm Absorber Model Reproduce the Soft X-Ray Spectra of MCG -6-30-15 and Markarian 766?

Author

Sako, Masao, Kahn, Steven M., Branduardi, Graziella, Kaastra, Jelle S., Brinkman, Albert C., Page, Mathew J., Behar, Ehud, Paerels, Frits, Kinkhabwala, Ali, Liedahl, Duane A., Willem, Jan, and Herder, den

Abstract

XMM-Newton RGS spectra of MCG -6-30-15 and Mrk 766 exhibit complex discrete structure, which was interpreted in a paper by Branduardi-Raymont and coworkers as evidence for the existence of relativistically broadened Lya emission from carbon, nitrogen, and oxygen, produced in the innermost regions of an accretion disk around a Kerr black hole. This suggestion was subsequently criticized in a paper by Lee and coworkers, who argued that for MCG -6-30-15, the Chandra HETG spectrum, which is partially overlapping the RGS in spectral coverage, is adequately fitted by a dusty warm absorber model, with no relativistic line emission. We present a reanalysis of the original RGS data sets in terms of the model by Lee and coworkers. Specifically, we show that (1) the explicit model given by Lee and coworkers differs markedly from the RGS data, especially at longer wavelengths, beyond the region sampled by the HETG; (2) generalizations of the Lee and coworkers model, with all parameters left free, do provide qualitatively better fits to the RGS data, but are still incompatible with the detailed spectral structure; (3) the ionized oxygen absorption-line equivalent widths are well measured with the RGS for both sources, and place very tight constraints on both the column densities and turbulent velocity widths of O VII and O VIII. The derived column densities are well below those posited by Lee and coworkers and are insufficient to play any role in explaining the observed edge-like feature near 17.5 A; (4) the lack of a significant neutral oxygen edge near 23 A places very strong limits on any possible contribution of absorption to the observed structure by dust embedded in a warm medium; and (5) the original relativistic line model with warm absorption proposed by Branduardi-Raymont and coworkers provides a superior fit to the RGS data, both in the overall shape of the spectrum and in the discrete absorption lines. We also discuss a possible theoretical interpretation for the putative relativistic Lya line emission in terms of the photoionized surface layers of the inner regions of an accretion disk. While there are still a number of outstanding theoretical questions about the viability of such a model, it is interesting to note that simple estimates of key parameters are roughly compatible with those derived from the observed spectra.

Published
2003

155. X-Ray Spectroscopy of ? Carinae with XMM-Newton

Author

Leutenegger, Maurice A., Kahn, Steven M., and Ramsay, Gavin

Abstract

We present XMM-Newton observations of the luminous star e Carinae, including a high-resolution soft X-ray spectrum of the surrounding nebula obtained with the Reflection Grating Spectrometer (RGS). The European Photon Imaging Camera (EPIC) image of the field around e Car shows many early-type stars and diffuse emission from hot, shocked gas. The EPIC spectrum of the star is similar to that observed in previous X-ray observations and requires two temperature components. The RGS spectrum of the surrounding nebula shows K-shell emission lines from hydrogen- and helium-like nitrogen and neon and L-shell lines from iron but little or no emission from oxygen. The observed emission lines are not consistent with a single temperature, but the range of temperatures observed is not large, spanning ~0.15-0.6 keV. We obtain upper limits for oxygen line emission and derive a lower limit of N/O > 9. This is consistent with previous abundance determinations for the ejecta of e Car and with theoretical models for the evolution of massive, rotating stars.

Published
2003

156. XMM-Newton Reflection Grating Spectrometer Observations of Discrete Soft X-Ray Emission Features from NGC 1068

Author

Kinkhabwala, Ali, Sako, Masao, Behar, Ehud, Kahn, Steven M., Paerels, Frits, Brinkman, Albert C., Kaastra, Jelle S., Feng, Ming, and Liedahl, Duane A.

Abstract

We present the first high-resolution, soft X-ray spectrum of the prototypical Seyfert 2 galaxy, NGC 1068. This spectrum was obtained with the XMM-Newton Reflection Grating Spectrometer (RGS). Emission lines from H-like and He-like low-Z ions (from C to Si) and Fe L-shell ions dominate the spectrum. Strong, narrow radiative recombination continua (RRCs) for several ions are also present, implying that most of the observed soft X-ray emission arises in low-temperature plasma (kTe ~ a few eV). This plasma is photoionized by the inferred nuclear continuum (obscured along our line of sight), as expected in the unified model of active galactic nuclei (AGNs). We find excess emission (compared to pure recombination) in all resonance lines (1s-np) up to the photoelectric edge, demonstrating the importance of photoexcitation as well. We introduce a simple model of a cone of plasma irradiated by the nuclear continuum; the line emission we observe along our line of sight perpendicular to the cone is produced through recombination/radiative cascade following photoionization and radiative decay following photoexcitation. A remarkably good fit is obtained to the H-like and He-like ionic line series, with inferred radial ionic column densities consistent with recent observations of warm absorbers in Seyfert 1 galaxies. Previous Chandra imaging revealed a large (extending out to ~500 pc) ionization cone containing most of the X-ray flux, implying that the warm absorber in NGC 1068 is a large-scale outflow. To explain the ionic column densities, a broad, flat distribution in the logarithm of the ionization parameter (x = LX/ner2) is necessary, spanning log x = 0-3. This suggests either radially stratified ionization zones, the existence of a broad density distribution (spanning a few orders of magnitude) at each radius, or some combination of both.

Published
2002

157. Long-Term Multiwavelength Observations of GRS 1758-258 and the Advection-dominated Accretion Flow Model

Author

Keck, John W., Craig, William W., Hailey, Charles J., Harrison, Fiona, Sub, Jae, Kahn, Steven M., Lubin, Philip M., McLean, Ryan, Pivovaroff, Michael J., Seiffert, Michael, Wurtz, Ron, and Ziock, Klaus P.

Abstract

We present a long-term multiwavelength light curve of Galactic black hole candidate GRS 1758-258 by combining previously published and archival data from Granat, ROSAT, the Compton Gamma Ray Observatory, the Rossi X-Ray Timing Explorer, BeppoSAX, ASCA, EXOSAT, and the Very Large Array. In addition, we include the first spectral results from the balloon-borne Gamma-Ray Arcminute Telescope Imaging System (GRATIS). In light of divergent analyses of the 1991-1993 ROSAT observations, we have reanalyzed these data; we find that the soft X-rays track the hard X-rays and that the fits require no blackbody component--indicating that GRS 1758-258 did not go to the high state in 1993. We offer an interpretation of these long-baseline data based on the advection-dominated accretion flow (ADAF) model for a system withimg1.gif [?] img1.gifcrit. We find that the 1990-1993 coeval hard and soft X-ray observations support the ADAF predictions. We discuss a new way to constrain black hole mass with spectral data and the ADAF theory and apply this technique to GRS 1758-258 to find M1 [?] 8-9 M at an assumed distance of 8.5 kpc. Further investigations of the ADAF model allow us to evaluate the model critically against the 1996 data and flux-flux diagram of Barret, McClintock, & Grindlay and to understand the limits of the latter's "X-ray burster box."

Published
2001

158. The ChandraIron-L X-Ray Line Spectrum of Capella

Author

Behar, Ehud, Cottam, Jean, and Kahn, Steven M.

Abstract

An analysis of the iron L-shell emission in the publicly available spectrum of the Capella binary system, as obtained by the High Energy Transmission Grating Spectrometer on board the Chandra X-Ray Observatory, is presented. The atomic-state model, based on the HULLAC code, is shown to be especially adequate for analyzing high-resolution X-ray spectra of this sort. Almost all of the spectral lines in the 10-18 Å wavelength range are identified. It is shown that, for the most part, these lines can be attributed to emission from L-shell iron ions in the Capella coronae. Possibilities for electron temperature diagnostics using line ratios of Fe16+are demonstrated. It is shown that the observed iron-L spectrum can be reproduced almost entirely by assuming a single electron temperature of kTe= 600 eV. This temperature is consistent both with the measured fractional ion abundances of iron and with the temperature derived from ratios of Fe16+lines. A volume emission measure of 1053cm-3is calculated for the iron L-shell emitting regions of the Capella coronae, indicating a rather small volume of 1029cm3for the emitting plasma if an electron density of 1012cm-3is assumed.

Published
2001
Full Text
View/download PDF

159. Interstellar X-Ray Absorption Spectroscopy of Oxygen, Neon, and Iron with the Chandra LETGS Spectrum of X0614+091

Author

Paerels, Frits, der, van, Boggende, den, Drake, Jeremy J., Kahn, Steven M., Savin, Daniel W., and McLaughlin, Brendan M.

Abstract

We find resolved interstellar O K, Ne K, and Fe L absorption spectra in the Chandra X-Ray Observatory Low-Energy Transmission Grating Spectrometer (LETGS) spectrum of the low-mass X-ray binary X0614+091. We measure the column densities in O and Ne and find direct spectroscopic constraints on the chemical state of the interstellar O. These measurements probably probe a low-density line of sight through the Galaxy, and we discuss the results in the context of our knowledge of the properties of interstellar matter in regions between the spiral arms.

Published
2001

160. Einstein observations of high luminosity X-ray binaries

Author

Kahn, Steven M.

Abstract

Recent observational advances in the study of high luminosity x-ray binaries have permitted investigation of the interaction of the outgoing x-radiation with the accreting matter surrounding the compact object. In two sources, 4U1822-37 and 4U2129+47, extended EINSTEIN coverage has led to the detection of partial x-ray eclipses, which indicate that the x-ray emitting regions must be extended in size. These have been interpreted as evidence for a large Compton-thick corona produced by evaporation of cool material off the surface of an accretion disk. In three other sources, 4U1915-05, 4U1624-49, and Cygnus X-2, evidence has been found for short x-ray absorption dips which are likely to be associated with obscuration by cool dense matter at the outer edge of the disk. In 4U1915-05, these dips are strictly periodic and determine the binary period for the system. In Cygnus X-2, the dips appear to be quasiperiodic, while in 4U1624-49, insufficient coverage has prevented clarification of the temporal properties of the absorption.

Published
1983
Full Text
View/download PDF

161. Oriented manifolds that fiber over $S\sp{4}$

Author

Kahn, Steven M.

Abstract

Necessary and sufficient conditions are given for an oriented manifold $ M$-sphere $ {S^4}$ to be oriented cobordant to a fiber bundle over $ {S^4}$ and $ {S^2}$ In addition, fiberings over products of surfaces are studied with complete solutions (in the sense above) being given in most cases including those of $ {S^2} \times {S^2}$ "$.

Published
1984

162. The X-ray observatory Suzaku

Author

Bautz, Mark, Kelley, Richard L., Petre, Robert, Figueroa, Enectali, Soong, Yang, Gendreau, Keith, Griffiths, Richard E., Harrus, Ilana, White, Nicholas E., Hasinger, Gunther, Henry, Patrick J., Holt, Stephen S., Hornschemeier, Ann, Hughes, John P., Hwang, Una, Smith, Randall, Kahn, Steven M., Kilbourne, Caroline, Kissel, Steve, Szymkowiak, Andrew E., Madejski, Greg M., Markowitz, Alex, Matsumoto, Chiho, Matsumoto, Hironori, Mccammon, Dan, Moseley, Harvey, Mushotzky, Richard, Nousek, John A., Chan, Kai-Wing, Ozawa, Hideki, Parmer, Arvind N., Pence, William D., Turner, Martin J. L., Angelini, Lorella, Arnaud, Keith, Boyce, Kevin, Brown, Gregory V., Porter, F. Scott, Cottam, Jean, Reeves, James N., Ricker, George R., Doty, John, Sanders, Wilton T., Fabian, Andrew C., Serlemitsos, Peter, Tashiro, Makoto, Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tomida, Hiroshi, Torii, Ken'ichi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsuru, Takeshi Go, Ueda, Yoshihiro, Ueno, Shiro, Ueno, Masaru, Uno, Shin'ichiro, Urata, Yuji, Watanabe, Shin, Yamamoto, Norimasa, Ishida, Manabu, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Ishisaki, Yoshitaka, Isobe, Naoki, Itoh, Masayuki, Iyomoto, Naoko, Kamae, Tuneyoshi, Katagiri, Hideaki, Kataoka, Jun, Mitsuda, Kazuhisa, Inoue, Hajime, Katayama, Haruyoshi, Koyama, Katsuji, Kunieda, Hideyo, Makishima, Kazuo, Ogawara, Yoshiaki, Takahashi, Tadayuki, Tsunemi, Hiroshi, Anabuki, Naohisa, Kawai, Nobuyuki, Awaki, Hisamitsu, Bamba, Aya, Dotani, Tadayasu, Ebisawa, Ken, Ezoe, Yuichiro, Fujimoto, Ryuichi, Fukazawa, Yasushi, Furusho, Tae, Furuzawa, Akihiro, Kinugasa, Kenzo, Haba, Yoshito, Hamaguchi, Kenji, Hatsukade, Isamu, Hayashida, Kiyoshi, Hiraga, Junko S., Kitamoto, Shunji, Kohama, Mitsuhiro, Kohmura, Takayoshi, Kokubun, Motohide, Kotani, Taro, Kotoku, Jun'ichi, Kubota, Aya, Maeda, Yoshitomo, Makino, Fumiyoshi, Matsuoka, Masaru, Matsushita, Kyoko, Mihara, Tatehiko, Misaki, Kazutami, Miyata, Emi, Mizuno, Tsunefumi, Mori, Koji, Mori, Hideyuki, Morii, Mikio, Mukai, Koji, Murakami, Hiroshi, Murakami, Toshio, Nagase, Fumiaki, Namiki, Masaaki, Negoro, Hitoshi, Nakazawa, Kazuhiro, Okajima, Takashi, Ogasaka, Yasushi, Ohashi, Takaya, Oshima, Tai, Ota, Naomi, Ozaki, Masanobu, Sakurai, Ikuya, Senda, Atsushi, Shibata, Ryo, Suzuki, Motoko, Takahashi, Hiromitsu, Tamagawa, Toru, Tamura, Keisuke, Tamura, Takayuki, and Tanaka, Yasuo

Subjects
Physics, Scientific instrument, instrumentation, Spacecraft, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Astrophysics, X-rays: general, Space and Planetary Science, Observatory, space vehicles, space vehicles: instruments, business
Abstract

著者人数: 143名, Accepted: 2006-09-27, 資料番号: SA1000631000

163. Large Synoptic Survey Telescope: Dark Energy Science Collaboration

Author

Abate, Alexandra, Aldering, Greg, Allen, Steven W., Ansari, Reza, Antilogus, Pierre, Applegate, Douglas, Astier, Pierre, Aubourg, Eric, Bahcall, Neta A., Bard, Deborah, Barkhouse, Wayne A., Bartlett, James G., Bean, Rachel, Becker, Andrew, Beckmann, Volcker, Bernstein, Gary, Biswas, Rahul, Blanc, Guillaume, Bongard, Sebastien, Bosch, James, Boutigny, Dominique, Bradac, Marusa, Bradshaw, Andrew, Brunner, Robert J., Burchat, Patricia R., Burke, David L., Cahn, Robert, Campagne, Jean-Eric, Carrasco Kind, Matias, Chihway Chang, Cheu, Elliott C., Chiang, James, Cinabro, David, Claver, Chuck, Clowe, Douglas, Cohn, Joanne D., Connolly, Andrew, Cooray, Asantha, Croft, Rupert A. C., Cui, Wei, Cunha, Carlos, Antonio, Ian P., Digel, Seth W., Di Matteo, Tiziana, Dodelson, Scott, Dore, Olivier, Dubois, Richard, Dubois-Felsmann, Gregory P., Ealet, Anne, Escoffier, Stephanie, Fassnacht, Chris, Finley, David A., Fouchez, Dominique, Frieman, Joshua A., Ganga, Ken, Gangler, Emmanuel, Garzoglio, Gabriele, Gawiser, Eric, Gilman, Fred, Gilmore, Kirk, Gladney, Larry, Glanzman, Thomas, Gottschalk, Erik E., Gnedin, Nickolay Y., Gris, Philippe, Guy, Julien, Habib, Salman, Heitmann, Katrin, Hilbert, Stefan, Ho, Shirley, Hogan, Craig, Honscheid, Klaus, Huard, Zachary, Huff, Eric M., Ivezic, Zeljko, Jain, Bhuvnesh, Jarvis, Mike, Jee, M. James, Jeltema, Tesla, Jha, Saurabh W., Johns, Kenneth A., Johnson, Anthony S., Johnson, Robert P., Kahn, Steven M., Kent, Stephen, Kessler, Richard, Kiessling, Alina, Kim, Alex G., Kirkby, David, Kirshner, Robert P., Kovacs, Eve V., Knox, Lloyd, Kratochvil, Jan M., Kuhlmann, Steve, Levi, Michael, Li, Guoliang, Lin, Huan, Linder, Eric, Lupton, Robert, Ma, Zhaoming, Macintosh, Bruce, Mandelbaum, Rachel, Mantz, Adam, Marshall, Philip J., Marshall, Stuart, May, Morgan, Mcdonald, Patrick, Meadows, Brian, Melchior, Peter M., Menard, Brice, Moniez, Marc, Morandi, Andrea, Morris, R. Glenn, Newman, Jeffrey A., Neyrinck, Mark C., Nugent, Peter, O Connor, Paul, Olivier, Scot S., Padmanabhan, Nikhil, Pain, Reynald, Peng, En-Hsin, Perdereau, Olivier, Perlmutter, Saul, Peterson, John R., Petrosian, Vahé, Plaszczynski, Stephane, Pope, Adrian C., Raccanelli, Alvise, Rasmussen, Andrew, Reil, Kevin, Rhodes, Jason, Ricker, Paul M., Ricol, Jean-Stephane, Roe, Natalie, Roodman, Aaron, Rosenberg, Leslie, Roucelle, Cecile, Russo, Stefano, Sako, Masao, Schindler, Rafe H., Schmidt, Samuel J., Schneider, Michael D., Sehgal, Neelima, Seljak, Uros, Sembroski, Glenn, Seo, Hee-Jong, Shipsey, Ian, Singal, Jack, Spergel, David, Soares-Santos, Marcelle, Spinka, Harold, Stebbins, Albert, Strauss, Michael A., Stubbs, Christopher W., Tao, Charling, Thaler, Jon J., Thomas, Rollin C., Thorman, Paul A., Tilquin, Andre, Trac, Hy, Treu, Tommaso, Tristram, Matthieu, Tyson, J. Anthony, Wandelt, Benjamin D., Wang, Yun, Wechsler, Risa H., Wenaus, Torre, White, Martin, Wittman, David, Wood-Vasey, W. Michael, Xin, Bo, Yoachim, Peter, Zentner, Andrew R., and Zhan, Hu

164. LSST Science Book, Version 2.0

Author

Lsst, Science Collaboration, Abell, Paul A., Allison, Julius, Anderson, Scott F., Andrew, John R., Angel, J. Roger P., Armus, Lee, Arnett, David, Asztalos, S. J., Axelrod, Tim S., Bailey, Stephen, Ballantyne, D. R., Bankert, Justin R., Barkhouse, Wayne A., Barr, Jeffrey D., Barrientos, L. Felipe, Barth, Aaron J., Bartlett, James G., Becker, Andrew C., Becla, Jacek, Beers, Timothy C., Bernstein, Joseph P., Biswas, Rahul, Blanton, Michael R., Bloom, Joshua S., Bochanski, John J., Boeshaar, Pat, Borne, Kirk D., Bradac, Marusa, Brandt, W. N., Bridge, Carrie R., Brown, Michael E., Brunner, Robert J., Bullock, James S., Burgasser, Adam J., Burge, James H., Burke, David L., Cargile, Phillip A., Chandrasekharan, Srinivasan, Chartas, George, Chesley, Steven R., Chu, You-Hua, Cinabro, David, Claire, Mark W., Claver, Charles F., Clowe, Douglas, Connolly, A. J., Cook, Kem H., Cooke, Jeff, Cooray, Asantha, Covey, Kevin R., Culliton, Christopher S., Jong, Roelof, Vries, Willem H., Debattista, Victor P., Delgado, Francisco, Antonio, Ian P., Dhital, Saurav, Di Stefano, Rosanne, Dickinson, Mark, Dilday, Benjamin, Djorgovski, S. G., Dobler, Gregory, Donalek, Ciro, Dubois-Felsmann, Gregory, Durech, Josef, Eliasdottir, Ardis, Eracleous, Michael, Eyer, Laurent, Falco, Emilio E., Fan, Xiaohui, Fassnacht, Christopher D., Ferguson, Harry C., Fernandez, Yanga R., Fields, Brian D., Finkbeiner, Douglas, Figueroa, Eduardo E., Fox, Derek B., Francke, Harold, Frank, James S., Frieman, Josh, Fromenteau, Sebastien, Furqan, Muhammad, Galaz, Gaspar, Gal-Yam, A., Garnavich, Peter, Gawiser, Eric, Geary, John, Gee, Perry, Gibson, Robert R., Gilmore, Kirk, Grace, Emily A., Green, Richard F., Gressler, William J., Grillmair, Carl J., Habib, Salman, Haggerty, J. S., Hamuy, Mario, Harris, Alan W., Hawley, Suzanne L., Heavens, Alan F., Hebb, Leslie, Henry, Todd J., Hileman, Edward, Hilton, Eric J., Hoadley, Keri, Holberg, J. B., Holman, Matt J., Howell, Steve B., Infante, Leopoldo, Ivezic, Zeljko, Jacoby, Suzanne H., Jain, Bhuvnesh, R, Jedicke, Jee, M. James, Garrett Jernigan, J., Jha, Saurabh W., Johnston, Kathryn V., Jones, R. Lynne, Juric, Mario, Kaasalainen, Mikko, Styliani, Kafka, Kahn, Steven M., Kaib, Nathan A., Kalirai, Jason, Kantor, Jeff, Kasliwal, Mansi M., Keeton, Charles R., Kessler, Richard, Knezevic, Zoran, Kowalski, Adam, Krabbendam, Victor L., Krughoff, K. Simon, Kulkarni, Shrinivas, Kuhlman, Stephen, Lacy, Mark, Lepine, Sebastien, Liang, Ming, Lien, Amy, Lira, Paulina, Long, Knox S., Lorenz, Suzanne, Lotz, Jennifer M., Lupton, R. H., Lutz, Julie, Macri, Lucas M., Mahabal, Ashish A., Mandelbaum, Rachel, Marshall, Phil, May, Morgan, Mcgehee, Peregrine M., Meadows, Brian T., Meert, Alan, Milani, Andrea, Miller, Christopher J., Miller, Michelle, Mills, David, Minniti, Dante, Monet, David, Mukadam, Anjum S., Nakar, Ehud, Neill, Douglas R., Newman, Jeffrey A., Nikolaev, Sergei, Nordby, Martin, O Connor, Paul, Oguri, Masamune, Oliver, John, Olivier, Scot S., Olsen, Julia K., Olsen, Knut, Olszewski, Edward W., Oluseyi, Hakeem, Padilla, Nelson D., Parker, Alex, Pepper, Joshua, Peterson, John R., Petry, Catherine, Pinto, Philip A., Pizagno, James L., Popescu, Bogdan, Prsa, Andrej, Radcka, Veljko, Raddick, M. Jordan, Rasmussen, Andrew, Rau, Arne, Rho, Jeonghee, Rhoads, James E., Richards, Gordon T., Ridgway, Stephen T., Robertson, Brant E., Roskar, Rok, Saha, Abhijit, Sarajedini, Ata, Scannapieco, Evan, Schalk, Terry, Schindler, Rafe, Schmidt, Samuel, Schmidt, Sarah, Schneider, Donald P., Schumacher, German, Scranton, Ryan, Sebag, Jacques, Seppala, Lynn G., Ohad Shemmer, Simon, Joshua D., Sivertz, M., Smith, Howard A., Allyn Smith, J., Smith, Nathan, Spitz, Anna H., Stanford, Adam, Stassun, Keivan G., Strader, Jay, Strauss, Michael A., Stubbs, Christopher W., Sweeney, Donald W., Szalay, Alex, Szkody, Paula, Takada, Masahiro, Thorman, Paul, Trilling, David E., Trimble, Virginia, Tyson, Anthony, Berg, Richard, Vanden Berk, Daniel, Vanderplas, Jake, Verde, Licia, Vrsnak, Bojan, Walkowicz, Lucianne M., Wandelt, Benjamin D., Wang, Sheng, Wang, Yun, Warner, Michael, Wechsler, Risa H., West, Andrew A., Wiecha, Oliver, Williams, Benjamin F., Willman, Beth, Wittman, David, Wolff, Sidney C., Wood-Vasey, W. Michael, Wozniak, Przemek, Young, Patrick, Zentner, Andrew, Zhan, Hu, APC - Cosmologie, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), LSST, Bartlett, James, Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)

Subjects
Active galactic nucleus, Cosmology and Nongalactic Astrophysics (astro-ph.CO), [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], media_common.quotation_subject, Milky Way, FOS: Physical sciences, Large Synoptic Survey Telescope, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Weak gravitational lensing, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, media_common, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR.CO] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Redshift, Galaxy, Astrophysics - Solar and Stellar Astrophysics, Sky, [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics of Galaxies (astro-ph.GA), Dark energy, Instrumentation and Methods for Astrophysics, Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy., 596 pages. Also available at full resolution at http://www.lsst.org/lsst/scibook

176. Lichen Nitidus With Plasma Cell Infiltrate

Author

Eisen, Richard F., Stenn, Judith, Kahn, Steven M., and Bhawan, Jag

Abstract

• The predominant cell types in the dermal infiltrate of lichen nitidus are lymphocytes and epithelioid cells. We report two cases of lichen nitidus in which numerous plasma cells were present in the dermal infiltrate.(Arch Dermatol 1985;121:1193-1194)

Published
1985
Full Text
View/download PDF

181. High-resolution x-ray spectroscopy with the EBIT Calorimeter Spectrometer.

Author

Porter, F. Scott, Adams, Joseph S., Beiersdorfer, Peter, Brown, Gregory V., Clementson, Joel, Frankel, Miriam, Kahn, Steven M., Kelley, Richard L., and Kilbourne, Caroline A.

Subjects
*X-ray spectroscopy, *SPECTROMETERS, *DETECTORS, *CRYOSTATS, *QUANTUM efficiency
Abstract

The EBIT Calorimeter Spectrometer (ECS) is a production-class 36 pixel x-ray calorimeter spectrometer that has been continuously operating at the Electron Beam Ion Trap (EBIT) facility at Lawrence Livermore National Laboratory for almost 2 years. The ECS was designed to be a long-lifetime, turn-key spectrometer that couples high performance with ease of operation and minimal operator intervention. To this end, a variant of the Suzaku/XRS spaceflight detector system has been coupled to a low-maintenance cryogenic system consisting of a long-lifetime liquid He cryostat, and a closed cycle, 3He pre-cooled adiabatic demagnetization refrigerator. The ECS operates for almost 3 weeks between cryogenic servicing and the ADR operates at 0.05 K for more than 60 hours between automatic recycles under software control. Half of the ECS semiconductor detector array is populated with mid-band pixels that have a resolution of 4.5 eV FWHM, a bandpass from 0.05–12 keV, and a quantum efficiency of 95% at 6 keV. The other half of the array has thick HgTe absorbers that have a bandpass from 0.3 to over 100 keV, an energy resolution of 33 eV FWHM, and a quantum efficiency of 32% at 60 keV. In addition, the ECS uses a real-time, autonomous, data collection and analysis system developed for the Suzaku/XRS instrument and implemented in off-the-shelf hardware for the ECS. Here we will discuss the performance of the ECS instrument and its implementation as a turnkey cryogenic detector system. [ABSTRACT FROM AUTHOR]

Published
2009
Full Text
View/download PDF

182. Performance of the EBIT calorimeter spectrometer.

Author

Porter, Frederick Scott, Gygax, John, Kelley, Richard L., Kilbourne, Caroline A., King, Jonathan M., Beiersdorfer, Peter, Brown, Gregory V., Thorn, Daniel B., and Kahn, Steven M.

Subjects
*CALORIMETERS, *SPECTROMETERS, *X-rays, *NONEQUILIBRIUM plasmas, *CHARGE exchange, *DETECTORS
Abstract

The EBIT calorimeter spectrometer (ECS) is a new high-resolution, broadband x-ray spectrometer that has recently been installed at the Electron Beam Ion Trap Facility (EBIT) at the Lawrence Livermore National Laboratory. The ECS is an entirely new production class spectrometer that replaces the XRS/EBIT spectrometer that has been operating at EBIT since 2000. The ECS utilizes a 32-pixel x-ray calorimeter array from the XRS instrument on the Suzaku x-ray observatory. Eighteen of the pixels are optimized for the 0.1–10 keV band and yield 4.5 eV full width at half maximum energy resolution and 95% quantum efficiency at 6 keV. In addition, the ECS includes 14 detector pixels that are optimized for the high-energy band with a bandpass from 0.5 to over 100 keV with 34 eV resolution and 32% quantum efficiency at 60 keV. The ECS detector array is operated at 50 mK using a five stage cryogenic system that is entirely automated. The instrument takes data continuously for over 65 h with a 2.5 h recycle time. The ECS is a nondispersive, broadband, highly efficient spectrometer that is one of the prime instruments at the EBIT facility. The instrument is used for studies of absolute cross sections, charge exchange recombination, and x-ray emission from nonequilibrium plasmas, among other measurements in our laboratory astrophysics program. [ABSTRACT FROM AUTHOR]

Published
2008
Full Text
View/download PDF

183. X-ray spectroscopy of astrophysical plasmas.

Author

Kahn SM, Behar E, Kinkhabwala A, and Savin DW

Abstract

We provide a qualitative review of key X-ray spectral diagnostics of astrophysical plasmas. We begin with a brief discussion of the two major types of equilibria, collisional ionization and photoionization, and then consider the behaviour of hydrogen-like, helium-like, iron L-shell and iron K-shell transitions for these separate cases. Where possible, we discuss explicit examples using high-resolution spectra acquired by the grating instruments on the Chandra and XMM-Newton observatories.

Published
2002
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results