Related papers: Algorithms and radiation dynamics for the vicinity…
It is difficult to implement numerical simulations on a region extending from the vicinity of a black hole to the Bondi radius. Most previous numerical simulations have primarily concentrated on the region close to the black hole. They…
We investigate the structure and stability of hypercritical accretion flows around stellar-mass black holes, taking into account neutrino cooling, lepton conservation, and firstly a realistic equation of state in order to properly treat the…
The spin measurement of black holes has important implications in physics and astrophysics. Regardless of the specific technique to estimate the black hole spin, all the current approaches assume that the space-time geometry around the…
Relativistic reflection features are commonly observed in the X-ray spectra of stellar-mass and supermassive black holes and originate from illumination of the inner part of the accretion disk by a hot corona. All the available relativistic…
These notes resulted from a series of lectures at the IAC winter school. They are designed to help students, especially those just starting in subject, to get hold of the fundamental tools used to study accretion powered sources. As such,…
We will summarize results of calculations of the modes of oscillation trapped within the inner region of accretion disks by the strong-field gravitational properties of a black hole (or a compact, weakly-magnetized neutron star). Their…
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…
Throughout the cosmic history, primordial black holes may experience an efficient phase of baryonic mass accretion from the surrounding medium. While the realm of accretion physics is marked by numerous uncertainties, and a comprehensive…
We present Fe Kalpha line profiles from and images of relativistic discs with finite thickness around a rotating black hole using a novel code. The line is thought to be produced by iron fluorescence of a relatively cold X-ray illuminated…
Self-consistent vertical structure models together with non-LTE radiative transfer should produce spectra from accretion disks around black holes which differ from multitemperature blackbodies at levels which may be observed. High…
Most of the X-ray emission from luminous accreting black holes emerges from within 20 gravitational radii. The effective emission radius is several times smaller if the black hole is rapidly spinning. General Relativistic effects can then…
Black hole accretion flows can be divided into two broad classes: cold and hot. Cold accretion flows, which consist of cool optically thick gas, are found at relatively high mass accretion rates. Prominent examples are the standard thin…
We perform stability analysis of an accretion disc around a stellar mass black hole. The cooling of the accretion flow due to bremsstrahlung and synchrotron radiation processes are considered. The solutions with shock are perturbed at the…
In this chapter we discuss the X-ray radiation from relativistic accretion disks around supermassive black holes, supposed to exist in the centers of Active Galactic Nuclei (AGN). Our focus is on the X-ray radiation, especially in the Fe…
The relativistically-broadened reflection spectrum, observed in both AGN and X-ray binaries, has proven to be a powerful probe of the properties of black holes and the environments in which they reside. Being emitted from the inner-most…
Binary black holes emit gravitational waves as they inspiral towards coalescence. Searches for electromagnetic counterparts to these gravitational waves rely on looking for common sources producing both signals. In this paper, we take a…
Disk accretion onto black holes is accompanied by collimated outflows (jets). In active galactic nuclei (AGN), the kinetic energy flux of the jet may exceed the bolometric luminosity of the disk a few orders of magnitude. This phenomena can…
By considering the steady-state Novikov-Thorne model, we study thin accretion disk processes for rotating hairy black holes in the framework of the Horndeski gravity. We obtain the electromagnetic properties of accretion disk around such…
We study the possibility of identifying dark matter in the galactic center from the physical properties of the electromagnetic radiation emitted from a optical-thin disk region around a static and spherically symmetric black hole. In…
Continuum spectrum emitted by the accretion disk around quasars hold a wealth of information regarding the strong gravitational field produced by the massive central object. Such strong gravity regime is often expected to exhibit deviations…