Related papers: On the space density of X-ray selected cataclysmic…
We present a systematic study of periodic X-ray sources in the massive globular cluster 47 Tuc, utilizing deep archival Chandra observations that resolve the cluster core and recently available eROSITA observations that cover the cluster…
Analysis of INTEGRAL/IBIS survey observations has revealed that the rare intermediate polar and asynchronous polar cataclysmic variables are consistently found to emit in the 20-100 keV energy band, whereas synchronous polars and the common…
Thousands of X-ray sources have been detected in the Galactic center (GC), most believed to be cataclysmic variables (CVs). As a potential probe of the old stellar population, in particular CVs, the existence and detectability of novae in…
We reconstruct the evolutionary path followed by cataclysmic variables (CVs) from the observed mass-radius relationship of their donor stars. Along the way, we update the semi-empirical CV donor sequence of Knigge (2006) and present a…
V405 Peg is a low-luminosity cataclysmic variable (CV) that was identified as the optical counterpart of the bright, high-latitude ROSAT all-sky survey source RBS1955. The system was suspected to belong to a largely undiscovered population…
Among hard X-ray Galactic sources detected in the Swift and INTEGRAL surveys, those discovered as accreting white dwarf binaries have suprisingly boosted in number in the recent years. The majority are identified as magnetic Cataclysmic…
We determine an expression for the cosmic variance of any "normal" galaxy survey based on examination of M* +/- 1 mag galaxies in the SDSS DR7 data cube. We find that cosmic variance will depend on a number of factors principally: total…
Large differences between the properties of the known sample of cataclysmic variable stars (CVs) and the predictions of the theory of binary star evolution have long been recognised. However, because all existing CV samples suffer from…
We present the results of a search for cataclysmic variables (CVs) in the Calan-Tololo survey. We detected a total number of 21 CVs, 12 of them are previously unknown objects. Our results suggest that the mismatch between the theoretically…
We briefly review our current knowledge of the space density of distant X-ray clusters as measured by several ROSAT serendipitous surveys. We compare old and new determinations of the cluster X-ray Luminosity Function (XLF) at increasing…
New observational constraints on the cosmic matter density $\Omega_m$ and an effectively redshift-independent equation of state parameter $w_x$ of the dark energy are obtained while simultaneously testing the strong and null energy…
A sample of 20 powerful extended radio galaxies with redshifts between zero and two were used to determine constraints on global cosmological parameters. Data for six radio sources were obtained from the VLA archive, analyzed, and combined…
We study the cosmic X-ray background (CXB) intensity variations on large angular scales using slew data of the RXTE observatory. We detect intensity variations up to ~2% on angular scales of 20--40deg. These variations are partly correlated…
Over six years of operation, the Catalina Real-time Transient Survey (CRTS) has identified 1043 cataclysmic variable (CV) candidates --- the largest sample of CVs from a single survey to date. Here we provide spectroscopic identification of…
We present the results of a systematic study of cataclysmic variables (CVs) and related systems, combining detailed binary-population synthesis (BPS) models with a grid of 120 binary evolution sequences calculated with a Henyey-type stellar…
We discuss several constraints on the properties of gamma-ray bursts (GRB) at cosmological distances. First we use the requirement that burst sources must be optically thin to pair production by photon-photon collisions in order to produce…
Spiral density waves are thought to be excited in the accretion discs of accreting compact objects, including Cataclysmic Variable stars (CVs). Observational evidence has been obtained for a handful of systems in outburst over the last two…
Coordinates, magnitudes and spectra are presented for 39 cataclysmic variables found in Sloan Digital Sky Survey spectra that were primarily obtained in 2006. Of these, 12 were CVs identified prior to the SDSS spectra (GY Cnc, GO Com, ST…
We present a measurement of the surface brightness of the cosmic X-ray background (CXB) in the Chandra Deep Fields, after excluding all detected X-ray, optical and infrared sources. The work is motivated by a recent X-ray stacking analysis…
Non-magnetic Cataclysmic Variables (CVs) show two distinct X-ray components: a hard, optically thin component and a soft, optically thick, blackbody-like component, both produced in the boundary layer between the accretion disk and the…