22 April 2004

Speaker: Paul Martini (Center for Astrophysics Clay Fellow)

Title: Clay Fellow Symposium
The Feeding of Nearby Supermassive Black Holes

Abstract: Supermassive black holes, with masses far greater than the most massive stars known, are believed to be at the center of every galaxy. Early in the history of the universe, these supermassive black holes grew at prodiguous rates by accreting large amounts of gas and many were visible as the extremely luminous quasars. At the present time, most black holes have settled down and only exhibit more modest growth as lower-luminosity, but still very energetic regions we call active galactic nuclei (AGN). The fuel for their growth likely originates from matter in the black hole's host galaxy that has lost essentially all of its angular momentum, yet the nature of the mechanism responsible for the angular momentum loss remains uncertain. I will describe studies of nearby AGN to determine the fueling mechanism or mechanisms and the implications of this work for the growth of galaxies, circumnuclear star formation, and the lifetime of AGN.

References for students:

2. Martini et al. 2003, ApJ, 589, 774
3. Shlosman et al. 1990, Nature, 345, 679