Related papers: Self-gravitating accretion discs
The nearest accretion disc to us in space if not time was the protosolar nebula. Remnants of this nebula thus potentially offer unique insight into how discs work. In particular the existence of chondrules, which must have formed in the…
We consider the accretion process in a disk with magnetic fields that are dragged in from the interstellar medium by gravitational collapse. Two diffusive processes are at work in the system: (1) "viscous" torques exerted by turbulent and…
Gas accretion of embedded stellar-mass black holes\,(sBHs) or stars in the accretion disk of active galactic nuclei\,(AGNs) will modify the mass distribution of these sBHs and stars, which will also affect the migration of the sBHs/stars.…
The core-accretion mechanism for gas giant formation may be too slow to create all observed gas giant planets during reasonable gas disk lifetimes, but it has yet to be firmly established that the disk instability model can produce…
A simple model of gas accretion in young galaxy disks suggests that fast turbulent motions can be driven by accretion energy for a time t_acc~2(epsilon^{0.5} GM^2/xi V^3)^{0.5} where epsilon is the fraction of the accretion energy going…
In this paper we report on the formation of magnetically-levitating accretion disks around supermassive black holes. The structure of these disks is calculated by numerically modelling tidal disruption of magnetized interstellar gas clouds.…
Accretion discs are fundamental to much of astronomy. They can occur around stars both young and old, around compact objects they provide a window into the extremes of physics, and around supermassive black holes in galaxy centres they…
Spectral Energy Distribution (SED) of the broad-band continuum emission from black-hole accretion discs can serve as a tool to measure parameters of the central body and constrain the geometry of the inner accretion flow. We focus on the…
Surprisingly, the relict cosmological constant has a crucial influence on properties of accretion discs orbiting black holes in quasars and active galactic nuclei. We show it by considering basic properties of both the geometrically thin…
Gas disks of spiral galaxies can be described as clumpy accretion disks without a coupling of viscosity to the actual thermal state of the gas. The model description of a turbulent disk consisting of emerging and spreading clumps (Vollmer &…
We perform 3D radiation hydrodynamic local shearing box simulations to study the outcome of gravitational instability (GI) in optically thick Active Galactic Nuclei (AGN) accretion disks. GI develops when the Toomre parameter QT \leq 1, and…
An accretion disk in an Active Galactic Nucleus (AGN) harbors and shields dust from external illumination: at the mid-plane of the disk around a $M_{{\rm BH}}=10^{7}M_{\odot}$ black hole, dust can exist at $0.1$pc from the black hole,…
Galactic outflows, driven by active galactic nuclei (AGN), play a crucial role in galaxy formation and in the self-regulated growth of supermassive black holes (BHs). AGN feedback couples to and affects gas, rather than stars, and in many,…
Massive black holes are believed to reside at the centres of most galaxies. They can be- come detectable by accretion of matter, either continuously from a large gas reservoir or impulsively from the tidal disruption of a passing star, and…
An unsolved issue in the standard core accretion model for gaseous planet formation is how kilometre-sized planetesimals form from, initially, micron-sized dust grains. Solid growth beyond metre sizes can be difficult both because the…
Multi-scale simulations have made it possible to follow gas inflows onto massive black holes (BHs) from galactic scales to the accretion disk. When sufficient gas is driven towards the BH, gravitational instabilities generically form…
We develop several aspects of the theory of gaseous astrophysical discs in which the gravity of the disc makes a significant contribution to its structure and dynamics. We show how the internal gravitational potential can be expanded in…
A fundamental role is attributed to supermassive black holes (SMBH), and the feedback they generate, in the evolution of galaxies. But theoretical models trying to reproduce the relation between the SMBH mass and stellar velocity dispersion…
The distribution of gravitational torques and bar strengths in the local Universe is derived from a detailed study of 163 galaxies observed in the near-infrared. The results are compared with numerical models for spiral galaxy evolution. It…
It has been suggested that the high metallicity generally observed in active galactic nuclei (AGNs) and quasars originates from ongoing star formation in the self-gravitating part of accretion disks around the supermassive black holes. We…