What Can Tidal Disruption Events Teach Us About Black Hole Accretion ?

Séminaire IPAG de Mitch Begelman (University of Colorado), jeudi 19 mars 2015 à 11h00, IPAG seminar room

For a year or more after a star is tidally disrupted by a black hole, debris can fall back at a rate that greatly exceeds the Eddington limit. Both observations and theoretical arguments indicate that mass loss is unable to regulate the rate at which matter is actually swallowed by the hole, leading to black hole growth rates and energy outputs that can exceed the Eddington limit by orders of magnitude. I will explain why regulation fails in such a case, and how this alternate mode of black hole growth could also be crucial for gamma-ray bursts and the rapid growth of supermassive black holes during the epoch of galaxy formation. I will also suggest that hyperaccreting black holes may be associated with the fastest jets, and that these are propelled by radiation pressure instead of magnetic forces.