Physics and Astronomy Colloquium Abstract

WiSE Speaker. SGM 101 (Note Different Location)

Bringing our Galaxy's Supermassive Black Hole and its Environs into Focus with Laser Guide Star Adaptive Optics

Andrea Ghez
UCLA Division of Astronomy and Astrophysics, University of California, Los Angeles
November 16, 2009

The proximity of our Galaxy's center presents a unique opportunity to study a galactic nucleus with orders of magnitude higher spatial resolution than can be brought to bear on any other galaxy. After more than a decade of astrometry from diffraction-limited speckle imaging on large ground-based telescopes, the case for a supermassive black hole at the Galactic center has gone from a possibility to a certainty, thanks to measurements of individual stellar orbits. The advent of adaptive optics technology has significantly expanded the scientific reach of our high-spatial-resolution infrared studies of the Galactic center. In this talk, I will present the results of several new adaptive optics studies on (1) our current understanding of the galaxy's central gravitational potential, (2) the puzzling problem of how young stars form in the immediate vicinity of the central black hole, (3) the surprising, apparent absence of the predicted central stellar cusp around the central supermassive black hole (an essential input into models for the growth of nuclear black holes), and (4) how future large ground-based telescope may allow these studies to test general relativity and cosmological models.


Dept. of Physics & Astronomy / Colloquium / physdept@usc.edu