Andrea M. Ghez, a professor of Physics & Astronomy who holds the Lauren B. Leichtman & Arthur E. Levine chair in Astrophysics, is one of the world's leading experts in observational astrophysics and heads UCLA's Galactic Center Group. She earned her B.S in Physics from MIT in 1987, and her PhD from Caltech in 1992 and has been on the faculty at UCLA since 1994. Best known for her ground-breaking work on the center of our Galaxy, which has led to the best evidence to date for the existence of supermassive black holes, she has received numerous honors and awards including the Crafoord Prize in Astronomy (she is the first woman to receive a Crafoord prize in any field), a MacArthur Fellowship, election to the National Academy of Sciences, the American Academy of Arts & Sciences, and the American Philosophical Society. Her work can be found in many public outlets including TED, NOVA's Monster of the Milky Way, Discovery's Swallowed by a Black Hole, and Griffith Observatoryi. For more information see http://www.astro.ucla.edu/~ghezgroup/gc/ and http://www.astro.ucla.edu/~ghez/.
Discover how Andrea Ghez and her team use the world's most powerful telescopes and next-generation imaging technology to peer into the center of our galaxy with more resolving power than ever before. By studying the motions of stars, Professor Ghez provides the best evidence that supermassive black holes exist, challenging our knowledge of fundamental physics and suggesting that most, if not all, galaxies harbor such objects at their cores. Her work has also shown that the environment near a central supermassive black hole looks nothing like what was expected. In the near future, she hopes to test Einstein's theory of relativity, as well as theories of galaxy formation and evolution confronting time-honored hypotheses.
Note: The AstroMcGill outreach group will organize observations of the night-sky following the lecture (weather permitting).
The proximity of the center of our Galaxy has presented us with 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. This advantage, along with the recent advances in high angular resolution imaging technologies, has allowed the first observations of individual stars at the very heart of a galaxy. After more than a decade, such observations have transformed the case for a supermassive black hole at the Galactic center from a possibility to a certainty, thanks to measurements of individual stellar orbits. The rapidity with which these stars move on small-scale orbits indicates that 4 million times the mass of the sun resides within a region comparable to the size of our solar system and provides the best evidence yet that supermassive black holes, which confront and challenge our knowledge of fundamental physics, do exist in the Universe. Subsequent high-resolution imaging studies of the Galactic center have shown that the stellar population near our Galaxy's supermassive back hole is quite different from the predications of theoretical models for the interaction between central black holes and their environs (an essential input into models for the growth of nuclear black holes). In particularly, the observations have revealed an abundance of young stars in a region that is inhospitable to star formation and, conversely, a dearth of old stars where as a stellar cusp is expected. Further improvements in measurement precision should enable tests of Einstein's theory of General Relativity in the extreme environment near a supermassive black hole.