Dynamics around supermassive black holes

Abstract

The dynamics of galactic nuclei reflects the presence of supermassive black holes (SBHs) in many ways. Single SBHs act as sinks, destroying a mass in stars equal to their own mass in roughly one relaxation time and forcing nuclei to expand. Formation of binary SBHs displaces a mass in stars roughly equal to the binary mass, creating low-density cores and ejecting hyper-velocity stars. Gravitational radiation recoil can eject coalescing binary SBHs from nuclei, resulting in offset SBHs and lopsided cores. We review recent work on these mechanisms and discuss the observable consequences.Comment: Invited talk. To appear in "2007 STScI Spring Symposium: Black Holes", eds. M. Livio & A. M. Koekemoer. (Cambridge University Press, in press) 26 pages, 12 figure