Black hole X-ray binaries represent one of the few means available for probing the supernova process, and one of the most useful means for understanding binary evolution under extreme conditions. At the present time, nearly all known black hole X-ray binaries have been selected due to luminous outbursts from their accretion disks. With eROSITA's imaging survey, it will be possible to build...
In high mass X-ray binaries (HMXBs), the black hole or neutron star accretes matter from the wind of a massive supergiant companion: the stellar wind drives changes in the accretion and thus the system’s X-ray emission. But the interaction of this emission with the wind material can also be used to study the wind itself, in particular its geometry, porosity (or clumpiness), mass-loss rate and...
We report on preliminary results of simultaneous eROSITA and XMM-Newton observations of the isolated neutron star PSR B0656$+$14. Data were obtained for almost 100 ks with eROSITA and 70 ks with XMM-Newton under excellent space weather conditions. The target was chosen to investigate a weak absorption feature between 0.5 and 0.6 keV that was tentatively identified in previous deep XMM-Newton...
Double degenerate white dwarf binaries result from episodes of common envelope evolution and evolve to short orbital period through gravitational wave emission. When the lighter of the two white dwarfs fills its Roche Lobe, mass transfer is initiated onto the heavier white dwarf, resulting in X-ray emission. At sufficiently close separation, the transferred mass does not form an accretion...
During first months of the SRG operation the ART-XC telescope (working energy range 4-30 keV) performed observations in different modes: scanning observations of a number of sky fields, pointing observations and all-sky survey. These observations allowed us to discover new transient sources with different observational properties. In particular, the typical time variability of new sources is...
We employ a binary population synthesis, combined with a detailed treatment of mass transfer onto neutron stars and black holes from the optical component with the help of the MESA stellar evolution code, to model populations of binary X-ray sources in galaxies. Wind-fed accreting neutron stars are calculated with taking into account different regimes of quasi-spherical accretion onto...
In August-September 2019, the ART-XC telescope scanned a large field (about 40 sq. deg) around the Galactic Center for nearly 3 weeks as part of the SRG Cal-PV phase. This resulted in a unique survey of the Galactic Bulge in the hard X-ray band of 4-30 keV. The main results of this survey will be presented, with a focus on the statistical properties of cataclysmic variables and low-luminosity...
We present results of the survey of two regions of the Galactic Plane (Norma
arm and the region around galactic longitude l=+20 deg), obtained with the ART-XC telescope
on board the SRG observatory in hard X-rays during the Cal-PV phase. The
total area covered by this survey was about 50 sq.degrees with the median
exposures of ~700 s in the l+20 field and ~1.4 ks in the Norma arm field,...
We will present the first results of a deep raster-scan
observation of the Galactic plane field, carried out by the
SRG/eROSITA telescope as a part of its CalPV program.
The field is centered at Galactic longitude l=20 degrees and covers a
total area of 25 sq. deg with a mean exposure of 8 ksec. We have
detected more than 2000 individual point X-ray sources,
demonstrating a wide variety of...
Low-mass X-ray binaries can lay dormant, remaining undetected for decades, until they are usually detected by X-ray monitoring satellites when they undergo bright outbursts. However, during these periods of quiescence between outbursts, low level accretion does occur but usually cannot be studied at X-ray energies due to their extremely low fluxes. We have been monitoring ~40-50 X-ray binaries...
