Related papers: GK Per and EX Hya: Intermediate polars with small …
Context. The energy balance of cataclysmic variables with strong magnetic fields is a central subject in understanding accretion processes on magnetic white dwarfs. With XMM-Newton, we perform a spectroscopic and photometric study of soft…
We present results of an analysis of broadband spectra of 14 intermediate polars obtained with the RXTE observatory (PCA and HEXTE spectrometers, 3-100 keV). By means of our calculations of the structure and the emergent spectrum of the…
The hard X-ray spectrum of magnetic cataclysmic variables can be modelled to provide a measurement of white dwarf mass. This method is complementary to radial velocity measurements, which depend on the (typically rather uncertain) binary…
The atmospheres of a large proportion of white dwarf stars are polluted by heavy elements that are expected to sink out of visible layers on short timescales. This has been interpreted as a signature of ongoing accretion of debris from…
We report an observed accretion rate of $\dot M_1 = (3.86\pm0.60)\times 10^{-11}$ $M_{\odot}$yr$^{-1}$ for the white dwarf in the short-period, intermediate polar EX Hya. This result is based upon the accretion-induced $4\pi$-averaged…
We study the absorption lines present in the spectra of the long-period cataclysmic variable GK Per during its quiescent state, which are associated with the secondary star. By comparing quiescent data with outburst spectra we infer that…
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…
We study simultaneous X-ray and optical observations of three intermediate polars EX Hya, V1223 Sgr and TV Col with the aim to understand the propagation of matter in their accretion flows. We show that in all cases the power spectra of…
We analyze the first X-ray observations with XMM-Newton of RXS J070407.9+262501 and 1RXS 180340.0+401214, in order to characterize their broad-band temporal and spectral properties, also in the UV/optical domain, and to confirm them as…
Context. On the basis of XMM-Newton observations, we investigate the energy balance of selected magnetic cataclysmic variables, which have shown an extreme soft-to-hard X-ray flux ratio in the ROSAT All-Sky Survey. Aims. We intend to…
The accretion induced neutron star magnetic field evolution is studied through considering the accretion flow to drag the field lines aside and dilute the polar field strength, and as a result the equatorial field strength increases and is…
The amplitude of the gravitational radiation from an accreting neutron star undergoing polar magnetic burial is calculated. During accretion, the magnetic field of a neutron star is compressed into a narrow belt at the magnetic equator by…
We present phase-resolved XMM_Newton data of three short period polars: V347 Pav, GG Leo and EU UMa. All three systems show one dominant accretion region which is seen for approximately half of the orbital cycle. GG Leo shows a strong dip…
XMM-Newton observations aimed at determining for the first time the broad-band X-ray properties of the faint high galactic latitude Intermediate Polar UU Col are presented. We performed X-ray timing analysis in different energy ranges of…
Using RXTE and ASCA data, we investigate the roles played by occultation and absorption in the X-ray spin pulse profile of the Intermediate Polar PQ Gem. From the X-ray light curves and phase-resolved spectroscopy, we find that the…
We study accretion induced collapse of magnetized white dwarfs as an origin of millisecond pulsars. We apply magnetized accretion disk models to the pre-collapse accreting magnetic white dwarfs and calculate the white dwarf spin evolution.…
Quasi-spherical subsonic accretion can be realized in slowly rotating wind-fed X-ray pulsars (XPSRs) at X-ray luminosities <4 10^{36} erg/s. In this regime the accreting matter settles down subsonically onto the rotating magnetosphere,…
We present data from long ROSAT HRI observations of the intermediate polars YY Dra and V709 Cas which show that V709 Cas, like YY Dra, exhibits a double-peaked X-ray pulse profile. Neither system shows evidence for X-ray beat period or…
White dwarfs are often found in binary systems with orbital periods ranging from tens of minutes to hours in which they can accrete gas from their companion stars. In about 15% of these binaries, the magnetic field of the white dwarf is…
We present results of a study of the fast timing variability of the magnetic cataclysmic variable (mCV) EX Hya. It was previously shown that one may expect the rapid flux variability of mCVs to be smeared out at timescales shorter than the…