相关论文: Constraints on the space density of intermediate p…
We use the complete, X-ray flux-limited ROSAT Bright Survey (RBS) to measure the space density of magnetic cataclysmic variables (mCVs). The survey provides complete optical identification of all sources with count rate >0.2/s over half the…
Intermediate Polars (IPs) are a group of cataclysmic variables (CVs) which are thought to contain white dwarfs which have a magnetic field strength in the range ~0.1-10MG. A significant fraction of the X-ray sources detected in recent deep…
White dwarf masses in cataclysmic variables are difficult to determine accurately, but are fundamental for understanding binary system parameters, as well as binary evolution. We investigate the X-ray spectral properties of a sample of…
We present preliminary results from the first 3 months of the Swift BAT high galactic latitude survey in the 14--195 keV band. The survey reaches a flux of \~10^{-11} erg/cm^2/s and has ~2.7' (90% confidence) positional uncertainties for…
For the past decade, it has been suggested that intermediate polars (IPs), a subclass of magnetic cataclysmic variables (CVs), are one of the main contributors to the hard diffuse X-ray emission from the Galactic center (GC) and Galactic…
A growing number of previously hidden Galactic X-ray sources are now detected with recent surveys performed by the Integral and Swift satellites. Most of these new sources eluded past surveys due to their large local X-ray extinction and…
We study the populations of X-ray sources in the Milky Way in the 15-55 keV band using a deep survey with the BAT instrument aboard the Swift observatory. We present the logN-logS distributions of the various source types and we analyze…
We present timing and spectral analysis of a sample of seven hard X-ray selected Cataclysmic Variable candidates based on simultaneous X-ray and optical observations collected with XMM-Newton , complemented with Swift/BAT and INTEGRAL/IBIS…
The hardness of the X-ray spectra of intermediate polars (IPs) is determined mainly by the white dwarf (WD) compactness (mass-radius ratio, M/R) and, thus, hard X-ray spectra can be used to constrain the WD mass. An accurate mass estimate…
(Abridged) We have discovered an intermediate polar (IP) in the 100 ks Chandra observation of Baade's Window (BW), a low extinction region at ~ 4 deg south of the Galactic Center. The source exhibits large X-ray modulations at a period of…
We report about the detection of 10 clusters of galaxies in the ongoing Swift/BAT all-sky survey. This sample, which comprises mostly merging clusters, was serendipitously detected in the 15--55 keV band. We use the BAT sample to…
Recently, unresolved hard (20-40 keV) X-ray emission has been discovered within the central 10 pc of the Galaxy, possibly indicating a large population of intermediate polars (IPs). Chandra and XMM-Newton measurements in the surrounding ~50…
We study the infrared (IR) properties of high-redshift galaxies using deep Spitzer 24, 70, and 160 micron data. Our primary interest is to improve the constraints on the total IR luminosities, L(IR), of these galaxies. We combine the…
We investigate the characteristics of bright flares for a sample of supergiant fast X-ray transients and their relation to the orbital phase. We have retrieved all Swift/BAT Transient Monitor light curves, and collected all detections in…
We present X-ray and optical observations of nova V407 Lup (Nova Lup 2016), previously well monitored in outburst, as it returned to quiescent accretion. The X-ray light curve in 2020 February revealed a clear flux modulation with a stable…
We report on the XMM-Newton observation of HP Cet and Swift J0820.6-2805, two X-ray photon sources that are candidates to be members of the intermediate polar class of cataclysmic variables. If the historical optical light curve of HP Cet…
The masses of white dwarfs (WDs) in intermediate polars (IPs) can be determined from the shape of their hard X-ray spectra. Here we study the importance of all possible systematic uncertainties in this X-ray spectroscopy method, including…
Cataclysmic variables can show rapid increases in optical flux. Intermediate polars (IPs), a subset with strong magnetic fields that disrupt the inner accretion disc, have been thought to possess truncated discs that rarely undergo the…
We present the first time resolved medium resolution optical spectroscopy of the recently identified peculiar Intermediate Polar (IP) 1RXSJ154814.5-452845, which allows us to precisely determine the binary orbital period…
Using X-ray observations from the NuSTAR and Swift satellites, we present temporal and spectral properties of an intermediate polar (IP) IGR J16547-1916. A persistent X-ray period at ~ 546 s confirming the optical spin period obtained from…