Related papers: Reflection physics in X-ray-emitting Symbiotic Sta…
We investigate the connections between the magnetic fields and the X-ray emission from massive stars. Our study shows that the X-ray properties of known strongly magnetic stars are diverse: while some comply to the predictions of the…
We review X-ray flux modulation from X-ray binaries on time scales corresponding to the orbital period and those at longer time scales (so called superorbital). Those modulations provide a powerful tool to constrain geometry of the…
We have reanalysed the ASCA X-ray spectrum of the bright symbiotic star CH Cyg, which exhibits apparently distinct hard and soft X-ray components. Our analysis demonstrates that the soft X-ray emission can be interpreted as scattering of…
We model the X-rays reprocessed by an accretion disk in a fiducial low-mass X-ray binary system with a neutron star primary. An atmosphere, or the intermediate region between the optically thick disk and a Compton-temperature corona, is…
Multiple reflection of X-rays may be important when an accretion disc and its hot corona have a complicated geometry, or if returning radiation due to gravitational light bending is important, or in emission from a funnel such as proposed…
We show that waves propagating in a transition disk can explain the short term temporal behavior of Cygnus X-1. In the transition disk model the spectrum is produced by saturated Comptonization within the inner region of the accretion disk…
Robust atmospheric and radiative transfer modeling will be required to properly interpret reflected light and thermal emission spectra of terrestrial exoplanets. This will help break observational degeneracies between the numerous…
There have been several surprising developments in our understanding of symbiotic binary stars and nova eruptions over the last decade or so based on multiwavelength data. For example, symbiotic stars without shell burning on their white…
We review observations and theoretical models of X-ray/gamma-ray spectra of radio-quiet Seyfert galaxies and of Galactic black-hole candidates (in the hard spectral state). The observed spectra share all their basic components: an…
X-ray reflection off the accretion disc surrounding a black hole, together with the associated broad iron K$\alpha$ line, has been widely used to constrain the innermost accretion-flow geometry and black hole spin. Some recent measurements…
It has been suggested that most Be/X-ray binaries are low X-ray luminosity nearby objects, containing white dwarfs (Chevalier & Ilovaisky 1998). We show that existing evidence indicates that all known Be/X-ray binaries are relatively bright…
Detailed studies of hot subdwarf B stars with red dwarf or brown dwarf companions can shed light on the effects of binarity on late stellar evolution. Such systems exhibit a strong, quasi-sinusoidal reflection effect due to irradiation of…
X-ray reflection models are used to constrain the properties of the accretion disk, such as the degree of ionization of the gas and the elemental abundances. In combination with general relativistic ray tracing codes, additional parameters…
We calculate the atmospheric structure of an accretion disk around a Kerr black hole and obtain its X-ray spectrum, which exhibits prominent atomic transitions under certain circumstances. The gravitational and Doppler (red)shifts of the C…
We present a brief overview of test-bed observations on accreting neutron star binaries for the Simbol-X mission. We show that Simbol-X will provide unique observations able to disclose the physical mechanisms responsible for their high…
While the non-thermal radio through at least near-infrared emission in the hard state in X-ray binaries (XRBs) is known to originate in jets, the source of the non-thermal X-ray component is still uncertain. We introduce a new model for…
Neutron star low-mass X-ray binaries accrete via Roche-lobe overflow from a stellar companion that is $\lesssim$ 1 M$_{\odot}$. The accretion disk in these systems can be externally illuminated by X-rays that are reprocessed by the…
We present a comprehensive study of the emission spectra from accreting sources. We use our new reflection code to compute the reflected spectra from an accretion disk illuminated by X-rays. This set of models covers different values of…
We present new models for illuminated accretion disks, their structure and reprocessed emission. We consider the effects of incident X-rays on the surface of an accretion disk by solving simultaneously the equations of radiative transfer,…
It is suggested that the three-segmented morphology of the soft X-ray emission from cluster and field stars may be understood in terms of the recent classification of rotating stars into three kinds: those lying on the convective sequence,…