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A Remarkable Low-Mass X-Ray Binary within 0.1 Parsecs of the Galactic Center
Brandt, W. N.; Ghez, A. M.; Muno, M. P. +5 more
Recent X-ray and radio observations by Muno et al. and Bower et al. have identified a transient low-mass X-ray binary (LMXB) located only 0.1 pc in projection from the Galactic center, CXOGC J174540.0-290031. In this paper, we report the detailed analysis of X-ray and infrared observations of the transient and its surroundings. Chandra observation…
Cloud Structure and Physical Conditions in Star-forming Regions from Optical Observations. II. Analysis
Andersson, B. -G.; Federman, S. R.; Sheffer, Y. +1 more
To complement the optical absorption line survey of diffuse molecular gas in Paper I, we obtained and analyzed far-ultraviolet H2 and CO data on lines of sight toward stars in Cep OB2 and Cep OB3. Possible correlations between column densities of different species for individual velocity components, not total columns along a line of sig…
Discovery of a Nearly Edge-on Disk around HD 32297
Schneider, Glenn; Hines, Dean C.; Silverstone, Murray D.
We report the discovery of a nearly edge-on disk about the A0 star HD 32297 seen in light scattered by the disk grains revealed in NICMOS PSF-subtracted coronagraphic images. The disk extends to a distance of at least 400 AU (3.3") along its major axis with a 1.1 µm flux density of 4.81 +/- 0.57 mJy beyond a radius of 0.3" from the coronagra…
XMM-Newton Observations of Evolution of Cluster X-Ray Scaling Relations at z=0.4-0.7
Vikhlinin, A.; Kotov, O.
We present a spatially resolved analysis of the temperature and gas density profiles of galaxy clusters at z=0.4-0.7 observed with XMM-Newton. These data are used to derive the total cluster mass within the radius r500 without assuming isothermality and also to measure the average temperature and total X-ray luminosity, excluding the co…
Identifying Lenses with Small-Scale Structure. II. Fold Lenses
Keeton, Charles R.; Gaudi, B. Scott; Petters, A. O.
When the source in a four-image gravitational lens system lies sufficiently close to a ``fold'' caustic, two of the lensed images lie very close together. If the lens potential is smooth on the scale of the separation between the two close images, the difference between their fluxes should approximately vanish, Rfold≡(F+-F
Observations of Separator Reconnection to an Emerging Active Region
Longcope, D. W.; Scott, J.; McKenzie, D. E. +1 more
Extreme-ultraviolet (EUV) observations of an emerging active region are used to study separator reconnection in the corona. We identify each EUV loop connecting the emerging polarity to a nearby existing active region over the 41 hr period beginning at emergence onset. Their geometrical resemblance to post-reconnection field lines from a magnetic …
Evolution of Field Early-Type Galaxies: The View from GOODS CDFS
Lisker, Thorsten; Mobasher, Bahram; Ferreras, Ignacio +2 more
We explore the evolution of field early-type galaxies in a sample extracted from the ACS images of the southern GOODS field. The galaxies are selected by means of a nonparametric analysis, followed by visual inspection of the candidates with a concentrated surface brightness distribution. We furthermore exclude from the final sample those galaxies…
On the Limb Darkening, Spectral Energy Distribution, and Temperature Structure of Procyon
Ludwig, H. -G.; Kervella, P.; Aufdenberg, J. P.
We have fit synthetic visibilities from three-dimensional (CO5BOLD+PHOENIX) and one-dimensional (PHOENIX, ATLAS 12) model stellar atmospheres of Procyon (F5 IV) to high-precision interferometric data from the VLT Interferometer (K band) and from the Mark III interferometer (500 and 800 nm). These data sets provide a test of theoretical …
Intrinsic Curvature in the X-Ray Spectra of BL Lacertae Objects
Perlman, Eric S.; Georganopoulos, Markos; Stocke, John T. +10 more
We report results from XMM-Newton observations of 13 X-ray bright BL Lacertae objects, selected from the Einstein Slew Survey sample (SSS). The survey was designed to look for evidence of departures of the X-ray spectra from a simple power-law shape (i.e., curvature and/or line features) and to find objects worthy of deeper study. Our data are gen…
Ultraviolet, X-Ray, and Optical Radiation from the Geminga Pulsar
Romani, R. W.; Pavlov, G. G.; Zavlin, V. E. +1 more
We observed the γ-ray pulsar Geminga with the FUV-MAMA and NUV-MAMA detectors of the Space Telescope Imaging Spectrometer to measure Geminga's spectrum and pulsations in the ultraviolet. The slope of the far-ultraviolet (FUV) spectrum is close to that of a Rayleigh-Jeans spectrum, suggesting that the FUV radiation is dominated by thermal emission …