Weighing a Quiescent Supermassive Black Hole with X-ray Emitting Gas

David Buote, UC Irvine

We report the first detection of a quiescent supermassive black hole by its gravitational influence on the hot ISM of its elliptical galaxy host. Using Chandra observations of NGC 4649 we constrained the mass of the supermassive black hole to be, MBH = 3.35^{+0.67}_{-0.95} x 10^9 Msun at 90% confidence, in good agreement with stellar kinematics measurements. This makes NGC 4649 one of only a handful of galaxies which have MBH measured by more than one method.