Formation of Supermassive Black Holes by Direct Infall in Pre-Galactic Haloes
Mitch Begelman (CU Boulder/JILA) - Oct 2 at 12:00 noon
The seeds of supermassive black holes may have formed via the direct
infall of gas in 10^4 K pregalactic haloes, without the intermediate
stage of Pop III star formation. Global gravitational instabilities
get rid of excess angular momentum, and the infalling gas forms a
self-gravitating, optically thick structure that we call a
"quasistar". As matter piles on, the core of the quasistar heats up
until it undergoes runaway neutrino cooling and collapses to form the
initial, 10 solar mass black hole. The black hole then grows by
accreting from the quasistar at an extremely super-Eddington rate,
reaching thousands of solar masses in less than a million years.
Concurrently, the quasistar expands to form a radiation
pressure-dominated, convective structure reminiscent of a red giant.
I will discuss the observational appearance of quasistars and their
detectability with JWST.
Relevant paper: Begelman, Volonteri and Rees 2006, "Formation of
supermassive black holes by direct collapse in pre-galactic haloes,"
MNRAS, 370, 289
The seminar will be held in 544 Campbell Hall.
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