Related papers: Accretion disk radiation dynamics and the cosmic b…
Magnetic fields in black hole accretion disks are associated with processes of mass accretion and energy amplification. The contribution of the magnetic field due to the magnetic polarization of the material induces effects on the physical…
Study of nucleosynthesis in accretion disks around black holes was initiated by Chakrabarti et al. (1987). In the present work we do the similar analysis using the state-of-the-art disk model, namely, Advective Accretion Disks. During the…
Observations of Galactic black hole sources are traditionally done in the classical X-ray range (2 -- 10 keV) due to sensitivity constraints. Most of the accretion power, however, is radiated above 10 keV and the study of these sources in…
In this thesis a computational tool for modelling spectral features of X-ray sources in a strong gravitational field is developed. Six transfer functions, the gravitational and Doppler shift, lensing, emission angle, relative time delay,…
This preprint is based on two articles accepted by MNRAS and ApJ. Our aim is to study the evolution of the orbit of a star under the influence of interactions with an accretion disc in an AGN. The model considered consists of a low-mass…
We consider the circular motion of test particles in the gravitational field of a static and axially-symmetric compact object described by the $q$-metric. To this end, we calculate orbital parameters of test particles on accretion disks…
Most of the luminosity of accreting black hole is emitted in the X-ray band. This radiation is believed to emerge, through inverse Compton process, from a hot (Te ~ 10^8 -10^9 K) optically thin (Thomson optical depth ~ 1) plasma probably…
This paper investigates the observable properties of a Kerr-Sen black hole surrounded by a thin accretion disk, focusing on the impact of the black hole's spin and charge on the image. Using ray-tracing techniques, we conduct a detailed…
We study spin oscillations of neutrinos in relativistic moving matter inside an accretion disk. These neutrinos are gravitationally scattered off a spinning Kerr black hole surrounded by a thick accretion disk. The disk can co-rotate and…
In this paper, perturbations of an accretion disk by a star orbiting around a black hole are studied. We report on a numerical experiment, which has been carried out by using a parallel-machine code originally developed by D\"{o}nmez…
The Novikov-Thorne accretion disk model is widely employed in astrophysics, yet computing its blackbody spectrum theoretically requires analytical expressions for the orbital parameters -- specific energy, angular momentum, and angular…
We extract elegant and concise analytic formulae for the mass and rotation parameters of the Kerr black hole as well as its distance from the Earth only in terms of directly measurable quantities of the accretion disk revolving in the black…
The models that seek to explain the reflection spectrum in black hole binaries usually invoke a point-like primary source of hard X-rays. This source illuminates the accretion disk and gives rise to the discrete (lines) and…
We investigate the dynamical interaction of a central star cluster surrounding a super-massive black hole and a central accretion disk. The dissipative force acting on stars in the disk leads to an enhanced mass flow towards the…
We study quantum gravity effects on radiation properties of thin accretion disks around a renormalization group improved (RGI-) Schwarzschild black hole. In the infrared (IR) limit of the asymptotically safe theory with higher derivatives,…
This paper continues the analysis of a set of general relativistic 3D MHD simulations of accreting tori in the Kerr metric with different black hole spins. We focus on bound matter inside the initial pressure maximum, where the…
Astrophysical black hole candidates are thought to be the Kerr black holes predicted by General Relativity, but the actual nature of these objects has still to be proven. The analysis of the electromagnetic radiation emitted by a…
If an accretion disk around a black hole is illuminated by hard X-rays from non-thermal coronae, fluorescent iron lines will be emitted from the inner region of the accretion disk. The emission line profiles will show a variety of strong…
We study the spectral properties of a very general class of accretion disks which can be decomposed into three distinct components apart from a shock at $r=r_s$: (1) An optically thick Keplerian disk on the equatorial plane ($r>r_s$), (2) A…
We calculate the structure of accretion disc around a rapidly rotating black hole with a super-Eddington accretion rate. The luminosity and height of the disc are reduced by the advection effect. In the case of a large viscosity parameter,…