Related papers: Resolving flows around black holes: numerical tech…
We study numerically the axisymmetric relativistic Bondi-Hoyle accretion of a supersonic ideal gas onto a fixed Schwarzschild background space-time described with horizon penetrating coordinates. We verify that a nearly stationary shock…
Born in rapidly evolving mini-halos during the first billion years of the Universe, super- massive black holes (SMBH) feed from gas flows spanning many orders of magnitude, from the cosmic web in which they are embedded to their event…
Accreting supermassive black hole binaries are powerful multimessenger sources emitting both gravitational and EM radiation. Understanding the accretion dynamics of these systems and predicting their distinctive EM signals is crucial to…
We analyse, using new analytical models and numerical general relativistic magnetohydrodynamic simulations, the three-dimensional properties of accretion flows inside the plunging region of black hole spacetimes (i.e., at radii smaller than…
Active galactic nucleus (AGN) feedback from accreting supermassive black holes (SMBHs) is an essential ingredient of galaxy formation simulations. The orbital evolution of SMBHs is affected by dynamical friction that cannot be predicted…
We obtain approximate analytical solutions of the Einstein equations close to the trapping horizon for a dynamical spherically symmetric black hole in the presence of a minimally coupled self-interacting scalar field. This is made possible…
We describe astrophysical processes around a black hole keeping primarily the physics of accretion in mind. In Section 1, we briefly discuss the formation, evolution and detection of black holes. We also discuss the difference of flow…
The fully analytical solution for isothermal Bondi accretion on a black hole (MBH) at the center of JJ two-component Jaffe (1983) galaxy models is presented. In JJ models the stellar and total mass density distributions are described by the…
Black hole feedback has been widely implemented as the key recipe to quench star formation in massive galaxies in modern semi-analytic models and hydrodynamical simulations. As the theoretical details surrounding the accretion and feedback…
We study the relativistic Bondi-Hoyle-Lyttleton accretion onto a Schwarzschild black hole (BH), which is surrounded by rigid and small, randomly distributed, bodies. These bodies are idealized representations of substructure like stars…
Supermassive black hole dynamics during galaxy mergers is crucial in determining the rate of black hole mergers and cosmic black hole growth. As simulations achieve higher resolution, it becomes important to assess whether the black hole…
The Bondi accretion rate of black holes in our and nearby galaxies Messier 87, NGC 3115, NGC 1600, and Cygnus A have been determined or constrained using Chandra or other observations. It, however, remains unknown how much mass from the…
We introduce a new model for the accretion and feedback of supermassive black hole (SMBH) binaries to the KETJU code, which enables us to resolve the evolution of SMBH binaries down to separations of tens of Schwarzschild radii in gas-rich…
Discovery of high-redshift (z > 6) supermassive black holes (BHs) may indicate that the rapid (or super-Eddington) gas accretion has aided their quick growth. Here, we study such rapid accretion of the primordial gas on to intermediate-mass…
In theoretical models of galaxy evolution, black hole feedback is a necessary ingredient in order to explain the observed exponential decline in number density of massive galaxies. Most contemporary black hole feedback models in…
We have studied numerically the so-called Bondi-Hoyle (wind) accretion on to a rotating (Kerr) black hole in general relativity. We have used the Kerr-Schild form of the Kerr metric, free of coordinate singularities at the black hole…
We present deep (250 ks) Chandra observations of the nearby galaxy group NGC 1600, which has at its centre an ultramassive black hole (17$\pm$1.5 billion M$_{\odot}$). The exceptionally large mass of the black hole coupled with its low…
In this paper we present a fully relativistic study of axisymmetric magnetohydrodynamic Bondi--Hoyle accretion onto a moving Kerr black hole. The equations of general relativistic magnetohydrodynamics are solved using high resolution shock…
Numerical simulations of MHD accretion flows in the vicinity of a supermasssive black hole provide important insights to the problem of why and how systems -- such as the Galactic Center -- are underluminous and variable. To access…
Dwarf galaxies are ideal laboratories to probe the interplay between galaxy formation and the growth of black holes (BHs) in the early Universe. Mounting observational evidence reveals the presence of BHs in low-mass galaxies across cosmic…