Search Publications
Eight-Dimensional Mid-Infrared/Optical Bayesian Quasar Selection
Brandt, W. N.; Myers, Adam D.; Schneider, Donald P. +11 more
We explore the multidimensional, multiwavelength selection of quasars from mid-infrared (MIR) plus optical data, specifically from Spitzer-Infrared Array Camera (IRAC) and the Sloan Digital Sky Survey (SDSS). Traditionally, quasar selection relies on cuts in two-dimensional color space despite the fact that most modern surveys (optical and IR) are…
High-Resolution X-Ray Spectroscopy of the Evolving Shock in the 2006 Outburst of RS Ophiuchi
Ness, J. -U.; Eyres, S. P. S.; Evans, A. +9 more
The evolution of the 2006 outburst of the recurrent nova RS Ophiuchi was followed with 12 X-ray grating observations with Chandra and XMM-Newton. We present detailed spectral analyses using two independent approaches. From the best data set, taken on day 13.8 after outburst, we reconstruct the temperature distribution and derive elemental abundanc…
Diffuse Cluster-Like Radio Emission in Poor Environments
Rudnick, Lawrence; Brown, Shea
We present a study of the spectral, polarimetric, morphological, and environmental properties of the diffuse radio source 0809+39 using observations taken with the Westerbork Synthesis Radio Telescope, the Very Large Array, and archival optical and X-ray data. The source has two distinct diffuse, steep-spectrum components, one in the north that is…
A New X-Ray Analysis of the Open Cluster Blanco 1 Using Wide-Field BVIc Photometric and Proper Motion Surveys
James, D. J.; Platais, I.; Cargile, P. A.
We perform a new analysis of the extant ROSAT and XMM-Newton X-ray surveys of the southern open cluster Blanco 1, utilizing new BVIc photometric and proper motion data sets. In our study, we match optical counterparts to 47 X-ray sources associated with Blanco 1 cluster members, six of which were listed in previous X-ray studies as clus…
XMM-Newton and Optical Observations of Cataclysmic Variables from the Sloan Digital Sky Survey
Szkody, Paula; Schmidt, Gary D.; Mukadam, Anjum +3 more
We report on XMM-Newton and optical results for six cataclysmic variables that were selected from Sloan Digital Sky Survey (SDSS) spectra because they showed strong He II emission lines, indicative of being candidates for containing white dwarfs with strong magnetic fields. While high X-ray background rates prevented optimum results, we are able t…
Multiwavelength Study of the Bright X-Ray Source Population in the Interacting Galaxies NGC 5774/NGC 5775
Gandhi, Poshak; Ghosh, Kajal K.; Gutiérrez, Carlos M. +3 more
A few nearby interacting galaxies are known that host elevated numbers of ultraluminous X-ray sources. Here we report the results of a multiwavelength study of the X-ray source population in the field of the interacting pair of galaxies NGC 5774/5775. A total of 49 discrete sources are detected, including 12 ultraluminous X-ray source candidates w…
X-Ray Absorption and Optical Extinction in the Partially Obscured Seyfert Nucleus in Mrk 1393
Grupe, D.; Wang, T. G.; Yuan, W. +3 more
We present a detailed study of the X-ray and optical spectra of the luminous Seyfert galaxy Mrk 1393, which revealed variable partial obscuration of the active nucleus. The X-ray spectra obtained by XMM-Newton and Swift show moderate absorption with a column density around 3 × 1021 cm-2, consistent with a dust-reddening inter…
XMM-Newton Observations of SDSS J143030.22 - 001115.1: An Unusually Flat-Spectrum Active Galactic Nucleus
Williams, R.; Grupe, D.; Mathur, S. +3 more
We present XMM-Newton observations of the type 1 active galactic nucleus (AGN) SDSS 1430 - 0011 (z = 0.1032). The low signal-to-noise ratio spectrum of this source obtained in a snap shot Chandra observation showed an unusually flat continuum. With the follow-up XMM-Newton observations, we find that the source spectrum is complex; it either has an…