DO CIRCUMNUCLEAR DENSE GAS DISKS DRIVE MASS ACCRETION ONTO SUPERMASSIVE BLACK HOLES?

Accretion onto Intermediate-mass Black Holes in Dense Protogalactic Clouds

We present the first results from two-dimensional simulations of radiatively-efficient accretion of metal-free gas onto intermediate-mass black holes. We fix the shape of the spectral energy distribution of the radiation produced near the event horizon and study the structure of the irradiated low-angular-momentum accretion flow over three orders of magnitude in radius from the black hole, 1014...

The Cosmological History of Accretion onto Supermassive Black Holes

It is argued that supermassive black holes in the nuclei of galaxies most likely have grown coevally with their host dark matter halos. A calculation based on PressSchechter within this framework shows that the mean rate of accretion of matter onto such black holes varies from a value about 0.003 of the Eddington rate at the present epoch to a value around 0.08 at redshift 3. The bulk of AGN ev...

Theory of Disk Accretion onto Supermassive Black Holes

Accretion onto supermassive black holes produces both the dramatic phenomena associated with active galactic nuclei and the underwhelming displays seen in the Galactic Center and most other nearby galaxies. I review selected aspects of the current theoretical understanding of black hole accretion, emphasizing the role of magnetohydrodynamic turbulence and gravitational instabilities in driving ...

Growing Supermassive Black Holes by Chaotic Accretion

We consider the problem of growing the largest supermassive black holes from stellar–mass seeds at high redshift. Rapid growth without violating the Eddington limit requires that most mass is gained while the hole has a low spin and thus a low radiative accretion efficiency. If, as was formerly thought, the black–hole spin aligns very rapidly with the accretion flow, even a randomly–oriented se...

Dark Matter Accretion into Supermassive Black Holes