Search Publications
X-ray Emission from Nitrogen-Type Wolf-Rayet Stars
Skinner, Stephen L.; Zhekov, Svetozar A.; Güdel, Manuel +2 more
We summarize new X-ray detections of four nitrogen-type Wolf-Rayet (WR) stars obtained in a limited survey aimed at establishing the X-ray properties of WN stars across their full range of spectral subtypes. None of the detected stars is so far known to be a close binary. We report Chandra detections of WR 2 (WN2), WR 18 (WN4), and WR 134 (WN6), a…
Morphologies of Radio-, X-ray-, and Mid-infrared-selected Active Galactic Nuclei
Griffith, Roger L.; Stern, Daniel
We investigate the optical morphologies of candidate active galaxies identified at radio, X-ray, and mid-infrared wavelengths. We use the Advanced Camera for Surveys General Catalog (ACS-GC) to identify 372, 1360, and 1238 active galactic nucleus (AGN) host galaxies from Very Large Array, XMM-Newton, and Spitzer Space Telescope observations of the…
Hard X-ray Emission Associated with White Dwarfs. III.
Chu, You-Hua; Bilíková, Jana; Gruendl, Robert A. +1 more
Hard X-ray emission associated with white dwarfs (WDs) can be used to diagnose the presence of late-type binary companions, mass accretion from companions, or physical processes with unknown origins. Since our previous systematic searches for hard X-ray emission associated with WDs, the Galactic WD catalog has been augmented by >10,000 new WDs …
Simultaneous X-ray and Ultraviolet Observations of the SW Sextantis Star DW Ursae Majoris
Dhillon, V. S.; Szkody, Paula; Hoard, D. W. +6 more
We present the first pointed X-ray observation of DW Ursae Majoris, a novalike cataclysmic variable (CV) and one of the archetype members of the SW Sextantis class, obtained with the XMM-Newton satellite. These data provide the first detailed look at an SW Sex star in the X-ray regime (with previous X-ray knowledge of the SW Sex stars limited prim…
Spitzer Observations of A1763. II. Constraining the Nature of Activity in the Cluster-feeding Filament with VLA and XMM-Newton Data
Fadda, Dario; Frayer, David T.; Durret, Florence +2 more
The A1763 superstructure at z = 0.23 contains the first galaxy filament to be directly detected using mid-infrared observations. Our previous work has shown that the frequency of starbursting galaxies, as characterized by 24 µm emission is much higher within the filament than at either the center of the rich galaxy cluster, or the field surr…
XMM-Newton Observations of the Enigmatic Long Period Eclipsing Binary Epsilon Aurigæ: Constraining the Physical Models
Wolk, Scott J.; Guinan, Edward; Pillitteri, Ignazio +1 more
We report on an XMM-Newton observation of the unusual, long period (F0 supergiant + cool disk companion) eclipsing binary star epsilon Aurigæ observed in X-rays prior to the onset of the 2009-2011 eclipse phase. While it appears certain that a disk-like body is obscuring the star, it remains unclear what kind of object is at the center of the disk…
Multiwavelength Observations of the Runaway Binary HD 15137
Gies, Douglas R.; Roettenbacher, Rachael M.; De Becker, Michaël +6 more
HD 15137 is an intriguing runaway O-type binary system that offers a rare opportunity to explore the mechanism by which it was ejected from the open cluster of its birth. Here, we present recent blue optical spectra of HD 15137 and derive a new orbital solution for the spectroscopic binary and physical parameters of the O star primary. We also pre…
XMM-Newton Observations of the Radio-Loud Broad Absorption Line Quasar FBQS J131213.5+231958
Mathur, Smita; Dai, Xinyu
We present XMM-Newton observations of the broad absorption line (BAL) quasar FBQS J131213.5+231958. The X-ray spectrum of the source can be well described by an absorbed power-law model in which the absorber is either ionized or only partially covers the continuum source. This can explain the apparent lack of absorption observed in the Chandra spe…