Related papers: Accretion onto Intermediate-Mass Black Holes in De…
Accretion onto central massive black holes in galaxies is often modelled with the Bondi solution. In this paper we study a generalization of the classical Bondi accretion theory, considering the additional effects of the gravitational…
We have carried out a numerical study of the effect of large scale magnetic fields on the rate of accretion from a uniform, isothermal gas onto a resistive, stationary point mass. Only mass, not magnetic flux, accretes onto the point mass.…
The massive black holes in most faint active galactic nuclei (AGNs) and even normal galaxies are still accreting gases, though their accretion rates are very low. Radiatively inefficient accretion flows (RIAFs) are supposed in these faint…
Feedback from energy liberated by gas accretion onto black holes (BHs) is an attractive mechanism to explain the exponential cut-off at the massive end of the galaxy stellar mass function (SMF). Semi-analytic models of galaxy formation in…
I review accretion and outflow in active galactic nuclei. Accretion appears to occur in a series of very small--scale, chaotic events, whose gas flows have no correlation with the large--scale structure of the galaxy or with each other. The…
(Abridged) Using an empirical relation between the broad line region size and optical continuum luminosity, we estimated the black hole mass and accretion rate for 135 AGNs with double-peaked broad emission lines in two samples. With black…
We present results from three-dimensional, self-gravitating radiation hydrodynamical models of gas accretion by planetary cores. In some cases, the accretion flow is resolved down to the surface of the solid core -- the first time such…
We study the problem of steady-state spherical accretion onto a black hole, in which the internal energy of the flow is governed by radiation and photon diffusion dominates the energy flux at large radii. In the free-fall limit, the fluid…
The intent of this letter is to point out that the accretion of a ghost condensate by black holes could be extremely efficient. We analyze steady-state spherically symmetric flows of the ghost fluid in the gravitational field of a…
Context. Many low-redshift active galactic nuclei harbor a supermassive black hole accreting matter at low or medium rates. At such rates, the accretion flow usually consists of a cold optically thick disk, plus a hot, low density,…
We present near-infrared spectra of ten luminous, intermediate redshift quasars observed with SofI at the NTT of ESO/La Silla. With these rest-frame optical spectra we probe the Hb -[OIII] emission line region. Using the standard scaling…
In regions of star formation, protostars and newborn stars accrete mass from their natal clouds. These clouds are threaded by magnetic fields with a strength characterized by the plasma beta---the ratio of thermal and magnetic pressures.…
We perform numerical simulations of clouds in the Galactic Centre (GC) engulfing the nuclear super-massive black hole and show that this mechanism leads to the formation of gaseous accretion discs with properties that are similar to the…
The Bondi-Hoyle formula gives the approximate accretion rate onto a point particle accreting from a uniform medium. However, in many situations accretion onto point particles occurs from media that are turbulent rather than uniform. In this…
In order to find an explanation for the radiative quiescence of supermassive black holes in the local Universe, for a sample of nearby galaxies the most accurate estimates are collected for the mass of a central black hole M_BH, the nuclear…
We study the inner dynamics of accreting Eddington-inspired Born-Infeld black holes using the homogeneous approximation and taking charge as a surrogate for angular momentum. We show that there is a minimum of the accretion rate below which…
Simulations of black hole accretion have shown that magnetic stresses are present near and inside the innermost stable circular orbit (ISCO). This finding suggests that such flows may be more luminous than predicted by the standard…
A scaling relation based on thin-disc accretion theory has been used by some workers to determine the mass-inflow rate onto 20 high-redshift (z) and 80 Palomar-Green quasars. Based on several assumptions, it inexplicably implies that the…
We present time-dependent simulations of a two-phase accretion flow around a black hole. The accretion flow initially is composed of an optically thick and cool disc close to the midplane, while on top and below the disc there is a hot and…
Black hole accretion and jet production are areas of intensive study in astrophysics. Recent work has found a relation between radio luminosity, X-ray luminosity, and black hole mass. With the assumption that radio and X-ray luminosity are…