Related papers: Accretion onto a Charged Black Hole in Consistent …
We show that a single imperfect fluid can be used as a source to obtain the generalized McVittie metric as an exact solution to Einstein's equations. The mass parameter in this metric varies with time thanks to a mechanism based on the…
First we have assumed the most general static spherically symmetric black hole metric. The accretion of any general kind of fluid flow around the black hole have been investigated. The accretion of fluid flow around the modified Hayward…
We report on the second phase of our study of slightly rotating accretion flows onto black holes. We consider magnetohydrodynamical (MHD) accretion flows with a spherically symmetric density distribution at the outer boundary, but with…
We study effects of high-energy particles on the accretion flows onto a supermassive black hole and luminosities of escaping particles such as protons, neutrons, gamma-rays, and neutrinos. We formulate a one-dimensional model of the…
A brief summary of the properties of astrophysical black holes is presented. Various modes of accretion are distinguished, corresponding to accretion at rates from well below to well above the Eddington rate. The importance of mass loss is…
This paper presents a study of quasi-steady spherical accretion in the early Universe, before the formation of the first stars and galaxies. The main motivation is to derive the basic formulas that will be used in a companion paper to…
We examine the accretion of matter onto a black hole in scalar--tensor--vector gravity (STVG) also known as modified gravity (MOG). The gravitational constant is $G=G_{N} (1 + \alpha)$ where $\alpha$ is a parameter taken to be constant for…
In this work we investigate the accretion of cosmological fluids onto an intermediate-mass black hole at the centre of a globular cluster, focusing on the influence of the parent stellar system on the accretion flow. We show that the…
The choked accretion model consists of a purely hydrodynamical mechanism in which, by setting an equatorial to polar density contrast, a spherically symmetric accretion flow transitions to an inflow-outflow configuration. This scenario has…
Observations of black hole X-ray binaries and active galactic nuclei indicate that the accretion flows around black holes are composed of hot and cold gas, which have been theoretically described in terms of either a hot geometrically thick…
Many models of gamma-ray bursts (GRBs) involve accretion onto a compact object, usually a black hole, at a mass accretion rate of order a fraction of a solar mass per second. If the accretion disk is larger than a few tens or hundreds of…
Context. The Bondi spherical accretion solution has been used to model accretion onto compact objects in a variety of situations, from interpretation of observations to subgrid models in cosmological simulations. Aims. We aim to investigate…
The $5 - 20 M_\odot$ dark objects in X-ray binary systems and the $10^5 - 10^9 M_\odot$ dark objects in galactic nuclei are currently thought to be the Kerr black holes predicted by General Relativity. However, direct observational evidence…
Mass accretion rate is a key parameter in accretion disk theory. It determines black hole accretion mode. In large scale cosmological simulations studying galaxy formation and evolution, Bondi radius can at most be marginally resolved. In…
We investigate $4D$ Einstein-Gauss-bonnet gravity coupled to exponential electrodynamics in AdS background and found a static, spherically symmetric exact black hole solution. The horizon structure of black hole is discussed. Treating the…
Accretion of dark energy onto black holes will take place when dark energy is not a cosmological constant. It has been proposed that the time evolution of the mass of the black holes in binary systems due to dark energy accretion could be…
We investigate the motion of a massive particle around a spherically symmetric black hole surrounded by a stationary and radial inflow of perfect fluid. The background spacetime is modelled as a spherically symmetric solution to the…
Accreting black holes are observed to launch relativistic, collimated jets of matter and radiation. In some sources, discrete ejections have been detected with highly relativistic velocities. These particular sources typically have very…
We examine the thin accretion disk behaviors surrounding black holes embedded in cold dark matter halos and scalar field dark matter halos. We first calculate the event horizons and derive the equations of motion and effective potential in…
Accreting binaries containing a black hole are stellar systems composed of a normal star and a black hole. Because of the strong gravitational pull of the black hole, matter is removed from the companion star and falls into the compact ob…