Search Publications
Theoretical Interpretation of the Luminosity and Spectral Properties of GRB 031203
Ruffini, Remo; Bernardini, Maria Grazia; Fraschetti, Federico +3 more
The X-ray and gamma-ray observations of the source GRB 031203 by INTEGRAL are interpreted within our theoretical model. In addition to a complete spacetime parameterization of the GRB, we specifically assume that the afterglow emission originates from a thermal spectrum in the comoving frame of the expanding baryonic matter shell. By determining t…
X-Ray Timing, Spectroscopy, and Photometry of the Anomalous X-Ray Pulsar Candidate CXOU J010043.1-721134
Ransom, S. M.; Gaensler, B. M.; Kaspi, V. M. +2 more
We present new X-ray timing and spectral results on the 8.0 s X-ray pulsar CXOU J010043.1-721134 from a series of observations using the Chandra X-Ray Observatory. We found a spin period in 2004 January of 8.020392+/-0.000009 s. A comparison of this to the 2001 Chandra observations implies a period derivative P˙=(1.88+/-0.08)×10-11 s s<…
On the Combination of Differential Emission Measure Analysis and Rotational Tomography for Three-dimensional Solar EUV Imaging
Frazin, R. A.; Weber, M. A.; Kamalabadi, F.
Conventional differential emission measure (DEM) analysis allows one to determine the amount of plasma as a function of temperature along a given line of sight. A completely different technique called solar rotational tomography (SRT) exploits the view angles provided by solar rotation to determine the spatial distribution of emissivity in three d…
The First Precise Determination of an Optical-Far-Ultraviolet Extinction Curve Beyond the Local Group (z=0.83)
Kochanek, C. S.; Arribas, S.; Muñoz, J. A. +3 more
We present the optical-far-ultraviolet extinction curve of the dust in the lens galaxy of the gravitational lens system SBS 0909+532 (z=0.83). Extending our previous optical-UV estimate (from λ-10~2 to 5 µm-1) into the far ultraviolet (from λ-10~5 to 8 µm-1) is crucial f…
XMM-Newton View of the Ultraluminous X-Ray Sources in M51
Dewangan, Gulab C.; Griffiths, Richard E.; Miyaji, Takamitsu +2 more
We present results based on XMM-Newton observations of the nearby spiral galaxy M51 (NGC 5194 and NGC 5195). We confirm the presence of the seven known ultraluminous X-ray sources (ULXs) with luminosities exceeding the Eddington luminosity for a 10 Msolar black hole, a low-luminosity active galactic nucleus (LLAGN) with 2-10 keV luminos…
A New Technique for Deriving Prominence Mass from SOHO/EIT Fe XII (19.5 Nanometers) Absorption Features
Gilbert, Holly R.; Holzer, Thomas E.; MacQueen, R. M.
It is presently unclear what role prominences play in the initiation and dynamics of coronal mass ejections (CMEs), although erupting prominences are strongly correlated with CMEs. The masses of prominences involved in CMEs are not generally measured, but the accurate determination of such masses may help in assessing the dynamical importance of p…
Evolution in the Cluster Early-Type Galaxy Size-Surface Brightness Relation at z~=1
Demarco, R.; Infante, L.; Zheng, W. +41 more
We investigate the evolution in the distribution of surface brightness, as a function of size, for elliptical and S0 galaxies in the two clusters RDCS J1252.9-2927 (z=1.237) and RX J0152.7-1357 (z=0.837). We use multicolor imaging with the Advanced Camera for Surveys on the Hubble Space Telescope to determine these sizes and surface brightnesses. …
X-Ray Spectroscopy of Candidate Ultracompact X-Ray Binaries
Chakrabarty, Deepto; Juett, Adrienne M.
We present high-resolution spectroscopy of the neutron star/low-mass X-ray binaries (LMXBs) 4U 1850-087 and 4U 0513-40 as part of our continuing study of known and candidate ultracompact binaries. The LMXB 4U 1850-087 is one of four systems in which we had previously inferred an unusual Ne/O ratio in the absorption along the line of sight, most li…
SDSS J140228.22+632133.3: A New Spectroscopically Selected Gravitational Lens
Treu, Tommaso; Koopmans, Léon V. E.; Bolton, Adam S. +2 more
We present Gemini integral-field unit spectroscopy and Hubble Space Telescope (HST) F435W- and F814W-band images of a newly discovered four-image gravitational lens, SDSS J140228.22+632133.3 (hereafter SDSSJ1402). The system is the first of 49 spectroscopically selected gravitational lens candidates to be imaged with the Advanced Camera for Survey…
The Acoustic Showerglass. II. Imaging Active Region Subphotospheres
Braun, D. C.; Lindsey, Charles
Seismic diagnostics of the shallow subphotospheres of strong active regions are substantially impacted by large amplitude and phase perturbations introduced by overlying surface magnetic fields. These function as an ``acoustic showerglass'' that impairs the coherence of acoustic waves impinging onto the solar surface from below, degrading images o…