We study an accretion disc with a hot continuous corona. We assume that the corona itself accretes and therefore it is powered directly by the release of the gravitational energy and cooled by radiative interaction with the disc. We consider the vertical structure of such a corona and show that the radial infall is accompanied by strong vertical outtow. Such a model has two important consequenc...

Synchrotron emission from jets produced by X-ray binaries can be detected at optical and infrared (IR) frequencies. I show that optical/IR colour-magnitude diagrams of the outbursts of nine X-ray binaries successfully separate thermal disc emission from non-thermal jet emission, in both black hole and neutron star sources. A heated single-temperature blackbody is able to reproduce the observed ...

We have observed the luminous (L2−10 keV ≃ 6×10 erg s) radio–quiet quasar RBS 1124 (z = 0.208) with Suzaku. We report the detection of a moderately broad iron (Fe) line and of a weak soft X–ray excess. The X–ray data are very well described by a simple model comprising a power law X–ray continuum plus its reflection off the accretion disc. If the inner disc radius we measure (rin 6 3.8 gravitat...

We study the global stability of non-axisymmetric p-modes (also called inertial-acoustic modes) trapped in the inner-most regions of accretion discs around black holes. We show that the lowest-order (highest-frequency) p-modes, with frequencies ω = (0.5− 0.7)mΩISCO (where m = 1, 2, 3, · · · is the azimuthal wave number, ΩISCO is the disc rotation frequency at the Inner-most Stable Circular Orbi...

Transient spectral features have been discovered in the X-ray spectra of Active Galactic Nuclei, mostly in the 5–7 keV energy range. Several interpretations were proposed for the origin of these features. We examined a model of Doppler boosted blue horns of the iron line originating from a spot in a black hole accretion disc, taking into account different approximations of general relativistic ...

GRS 1915+105—the first stellar-scale, highly relativistic jet source identified— is a key system for our understanding of the disc-jet coupling in accreting black hole systems. Comprehending the coupling between inflow and outflow in this source is important not only for X-ray binary systems but has a broader relevance for studies of active galactic nuclei and gamma-ray bursts. In this paper, w...

We report spectral results from three BeppoSAX observations of the black hole candidate XTE J1650–500 during its 2001/2002 outburst. We find strong evidence for the presence of a broad and strongly relativistic Fe emission line. The line profile indicates an accretion disc extending down to two gravitational radii suggesting the presence of a rapidly rotating central Kerr black hole. Thanks to ...

The effects of strong gravity on the polarization of the Compton reflection from an X-ray illuminated accretion disc are studied. The gravitational field of a rotating black hole influences Stokes parameters of the radiation along the propagation to a distant observer. Assuming the lamp-post model, the degree and the angle of polarization are examined as functions of the observer’s inclination ...

The disc electrophoresis of lipoproteins of unfractionated rat plasma is described. The plasma was prestained with Sudan black B and electrophoretically separated at polyacrylamide gel concentrations of 7.5, 5, and 3.75%. At least four lipoprotein components were observed, and an additional 2-3 components in the main gel and 2-5 components in the spacer gel possibly were present. Densitometry o...

The dynamics of accretion onto a schwarzschild black hole is studied using Paczynski-Wiita pseudo newtonian potential. Steady state solution of the flow equations is obtained using thin disc approximation, including the effect of bremsstrahlung cooling in the energy equation. The topology of transonic solutions are got and the conditions for shock formation (Rankine-Hugoniot conditions) are che...