Astronomy Colloquium (2015 Spring Semester)

* Date : May 21

* Speaker :  Dr. Nicholas McConnell (IfA, Hawaii)

* Title :  The Black Hole Safari: Big Game Hunting in Massive Galaxies

* Abstract

The Black Hole Safari is a campaign to measure stellar kinematics and central black hole masses (MBH) in a large sample of giant elliptical galaxies, approximately doubling the number of dynamically measured black holes in these objects.  To date we have observed 31 early-type galaxies with integral-field spectrographs on the Keck, Gemini North, and Gemini South telescopes, including the most extreme members of rich galaxy clusters and their similarly luminous counterparts in weaker galaxy groups.  An improved census of black holes in the local universe will assess whether the linear relation between MBH and stellar spheroid mass arises naturally from hierarchical merging, and may shed light upon the origins of recently-discovered overmassive black holes.  Although we are well poised to improve the quantity of nearby black hole measurements, we must still consider several avenues for improving the quality — accuracy and precision — of determining MBH from dynamical models.