Description:

Title: Gravitational Encounters and the Evolution of Galactic Nuclei

Speaker: David Merritt, Rochester Institute of Technology

Abstract: Supermassive black holes are always associated with stars: the stars of the galactic nuclei in which they sit. The stars undergo gravitational encounters as they move in the gravitational potential of the black hole, causing their orbits to gradually evolve. After a long time, a quasi-steady state is reached in which loss of stars to the black hole is balanced by re-supply from large distances. This problem is well understood in the limit that the unperturbed stellar orbits can be approximated as straight lines. But closer to the black hole, classical theory breaks down, for two reasons: (1) the unperturbed motion is nearly Keplerian, implying long-lived correlations between the stars; and  (2) the effects of general relativity become increasingly important. I will present a computational framework for treating gravitational encounters near a massive black hole and present some new results about the distribution of stars and the feeding rate.

Host: Fred Rasio

Speaker Schedule

Keywords: Physics, Astronomy, colloquium