07 March 2002 CfA Colloquium


Title: Black Hole Demographics

Speaker: Laura Ferrarese

Abstract:

With the existence of supermassive black holes in galactic centers established beyond any reasonable doubt, the study of black hole demographics has become the focus of current research efforts. I will critically compare estimates of the mass density in supermassive black holes from the present day to the quasar era, derived using a variety of methods. These include dynamical mass estimates in local quiescent galaxies; reverberation mapping in active galaxies and quasars; and estimates of the mean density of compact objects based on quasar optical counts and observations of the X-ray background. I will then discuss how these observations can be used to learn about the formation and evolution not only of the black holes themselves, but also of their host stellar systems.

Reference for students:

Ferrarese et al. 2001, Supermassive Black Holes in Active Galactic Nuclei. I. The Consistency of Black Hole Masses in Quiescent and Active Galaxies, ApJ, 555, L97