Related papers: Radiative cooling changes the dynamics of magnetic…
The importance of the radiative feedback from SMBHs at the centers of elliptical galaxies is not in doubt, given the well established relations among electromagnetic output, black hole mass and galaxy optical luminosity. In addition,…
Most general relativistic magnetohydrodynamic simulations of black hole (BH) hot accretion flows are initialized with small rotating tori and produce stable jets with only small fluctuations. However, recent studies using larger scale…
Chaotic cold accretion (CCA) profoundly differs from classic black hole accretion models. Using 3D high-resolution simulations, we probe the impact of rotation on the hot and cold accretion flow in a typical massive galaxy. In the hot mode,…
We obtained thermal equilibrium solutions for optically thin, two-temperature black hole accretion disks incorporating magnetic fields. The main objective of this study is to explain the bright/hard state observed during the bright/slow…
High-redshift ($z>2$) blazars, with relativistic jets aligned toward us, probe the most powerful end of the active galactic nuclei (AGN) population. We aim at determining the black hole masses and mass accretion rates of high-$z$ blazars in…
We construct Super-Eddington Slim Disks models around both stellar and super-massive black holes by allowing the formation of a porous layer with a reduced effective opacity. We show that at high accretion rates, the inner part of the disks…
We solved the set of two-dimensional magnetohydrodynamic (MHD) equations for optically thin black hole accretion flows incorporating toroidal component of magnetic field. Following global and local MHD simulations of black hole accretion…
I present results from numerical simulations of gas dynamics outside luminous accretion disks in active galactic nuclei. The gas, gravitationally captured by a super massive black hole, can be driven away by the energy and momentum of the…
Black holes (BHs) surrounded by accretion disks are present in the Universe at different scales of masses, from microquasars up to the active galactic nuclei (AGNs). The current picture remains ad hoc due to the complexity of the magnetic…
A recent analysis of black hole scaling relations, used to estimate the local mass density in black holes, has indicated that the normalization of the scaling relations should be increased by approximately a factor of five. The local black…
We investigate the effect of conductive heating of the gas surrounding a geometrically thick accretion disk on the growth of a black hole at high redshift. If a black hole is accreting the surrounding gas at a super-Eddington rate, the…
Accretion at sustained or episodic super-Eddington (SE) rates has been proposed as a pathway to grow efficiently light seeds produced by Pop-III stars. We investigate if SE accretion can be sustained onto a black hole (BH) with $M_{\odot}…
We study the effect of radiative feedback on accretion onto intermediate mass black holes (IMBHs) using the hydrodynamical code ZEUS-MP with a radiative transfer algorithm. In this paper, the first of a series, we assume accretion from a…
We examine the small-scale dynamics of black hole accretion disks in which radiation pressure exceeds gas pressure. Local patches of disk are modeled by numerically integrating the equations of radiation MHD in the flux-limited diffusion…
We study a combined model of black hole - accretion disk - magnetosphere - jet symbiosis, applicable for supermassive black holes. We quantify the mass and spin evolution and we analyze how the limiting value of the spin parameter and the…
We find a new two-temperature hot branch of equilibrium solutions for stationary accretion disks around black holes. In units of Eddington accretion rate defined as $10L_{\rm Edd}/c^2$, the accretion rates to which these solutions…
Radiative efficiency of a slowly accreting black hole is estimated using a two-temperature model of accretion. The radiative efficiency depends on the magnetic field strength near the Schwarzschild radius. For weak magnetic fields (magnetic…
We perform a series of 2D smoothed particle hydrodynamics (SPH) simulations of gas accretion onto binaries via a circumbinary disc, for a range of gas temperatures and binary mass ratios ($q$). We show that increasing the gas temperature…
We study a truncated accretion disk using a well-resolved, semi-global magnetohydrodynamic simulation that is evolved for many dynamical times (6096 inner disk orbits). The spectral properties of hard state black hole binary systems and…
We report results from general relativistic radiation MHD (GRRMHD) simulations of a super-Eddington black hole (BH) accretion disk formed as a result of a tidal disruption event (TDE). We consider the fiducial case of a solar mass star on a…