Search Publications
The Two-dimensional XMM-Newton Group Survey: z < 0.012 Groups
Mulchaey, John S.; Finoguenov, Alexis; Davis, David S. +1 more
We present the results of the two-dimensional XMM-Newton Group Survey (2dXGS), an archival study of nearby galaxy groups. In this paper we consider 11 nearby systems (z<0.012) in Mulchaey et al., which span a broad range in X-ray luminosity from 1040 to 1043 ergs s-1. We measure the iron abundance and temperatur…
Ultraviolet Properties of Halo Coronal Mass Ejections: Doppler Shifts, Angles, Shocks, and Bulk Morphology
Raymond, J. C.; Ciaravella, A.; Kahler, S. W.
We present UV spectral information for 22 halo or partial halo CMEs observed by UVCS. The CME fronts show broad line profiles, while the line intensities are comparable to the background corona. The Doppler shifts of the front material are generally small, showing that the motion of gas in the fronts is mostly transverse to the line of sight. This…
E+A Galaxies with Blue Cores: Active Galaxies in Transition
Zabludoff, Ann I.; Zaritsky, Dennis; Yang, Yujin +1 more
Hubble Space Telescope (HST) ACS images reveal blue cores in four E+A, or post-starburst, galaxies. Follow-up spectroscopy shows that these cores have LINER spectra. The existence of LINERs, consistent with those in many elliptical galaxies, is yet one more piece of evidence that these postmerger, post-starburst, bulge-dominated galaxies will evol…
Near-Infrared and Optical Limits for the Central X-Ray Point Source in the Cassiopeia A Supernova Remnant
Pavlov, G. G.; Fesen, R. A.; Sanwal, D.
We set new near-infrared and optical magnitude limits for the central X-ray point source (XPS) in the Cassiopeia A supernova remnant based on HST images. Near-infrared images of the center of Cas A taken with the NICMOS 2 camera in combination with the F110W and F160W filters (~J and H bands) have magnitude limits >=26.2 and >=24.6, respecti…
The High-Velocity Outflow of PG 1211+143 May Not Be That Fast
Kaspi, Shai; Behar, Ehud
We analyze the X-ray spectrum of the quasar PG 1211+143 observed with the CCD and grating spectrometers on board XMM-Newton. Using an ion-by-ion fitting model, we find an outflow component of about 3000 km s-1, which includes absorption lines of K and L shell ions of the astrophysically abundant elements. We also identify and include in…
X-Ray-selected Intermediate-Redshift Groups of Galaxies
Mulchaey, John S.; Rosati, Piero; Lubin, Lori M. +2 more
We present spectroscopic confirmation of nine moderate-redshift galaxy groups and poor clusters selected from the ROSAT Deep Cluster Survey. The groups span the redshift range z~0.23-0.59 and have between 4 and 20 confirmed members. The velocity dispersions of these groups range from ~125 to 650 km s-1. Similar to X-ray groups at low re…
A Close Look at the Population of Supersoft and Quasi-soft X-Ray Sources Observed in M31 with XMM-Newton
Orio, Marina
The deepest X-ray images of M31, obtained with XMM-Newton, are examined to derive spectral and statistical properties of the population of the very soft X-ray sources. When classifying supersoft X-ray sources (SSSs) with criteria based on the same hardness ratios defined for recent Chandra observations, one-quarter of the selected SSSs turn out to…
A Catalog of Transient X-Ray Sources in M31
Williams, Benjamin F.; Garcia, Michael R.; Naik, S. +1 more
From 1999 October to 2002 August, 45 transient X-ray sources were detected in M31 by Chandra and XMM-Newton. We have performed spectral analysis of all XMM-Newton and Chandra ACIS detections of these sources, as well as flux measurements of Chandra HRC detections. The result is absorption-corrected X-ray light curves for these sources covering thi…
X-Ray Absorption and an X-Ray Jet in the Radio-loud Broad Absorption-line Quasar PG 1004+130
Brandt, W. N.; Garmire, G. P.; Gallagher, S. C. +4 more
We investigate the X-ray properties of PG 1004+130, a radio-loud broad absorption-line (BAL) quasar with a hybrid FR I/II radio morphology. This optically bright, low-redshift quasar was undetected by Einstein, marking it as anomalously X-ray weak relative to other radio-loud quasars. The 22.2 ks XMM-Newton and 41.6 ks Chandra observations present…
The Transparency of Solar Coronal Active Regions
Schmelz, J. T.; Brickhouse, N. S.
Resonance scattering has often been invoked to explain the disagreement between the observed and predicted line ratios of Fe XVII λ15.01 to Fe XVII λ15.26 (the ``3C/3D'' ratio). In this process photons of λ15.01, with its much higher oscillator strength, are preferentially scattered out of the line of sight, thus reducing the observed line ratio. …