Polarization images of accretion flow around supermassive black holes: Imprints of toroidal field structure

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

Imprints of accretion on gravitational waves from black holes

Black holes are superb sources of gravitational wave signals, for example when they are born in stellar collapse. We explore the subtleties that may emerge if mass accretion events increase significantly the mass of the black hole during its gravitational wave emission. We find the familiar dampedoscillatory radiative decay but now both decay rate and frequencies are modulated by the mass accre...

Accretion around supermassive black holes: the detection of the Balmer edge signature from quasars

The ultraviolet/optical continuum of quasars is thought to be from an accretion flow around a supermassive black hole, and it dominates the radiative output of quasars. However, the nature of this emission, often called the Big Blue Bump, has not been well understood. Robust evidence for its thermal nature would be a continuum opacity edge feature intrinsic to this component, but this has not b...

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...