91探花

Dr. Sarah Gallagher, an associate professor of physics and astronomy at the University of Western Ontario, will be at 91探花 as part of the 2017 Canadian Association of Physicists Lecture Tour. Her talk, 鈥淭he Biggest Blowhards: Windy Supermassive Black Holes,鈥� is Wednesday, March 22 at 4:30 pm in the Alex H. MacKinnon Auditorium, room 242 of 91探花鈥檚 Don and Marion McDougall Hall. All are welcome. Supermassive black holes reside in the centres of every massive galaxy including our own Milky Way. In relatively brief spurts, black holes grow as luminous quasars through the infall of material through an accretion disk. Remarkably, the light from the accretion disk can outshine all of the stars in the host galaxy by a factor of a thousand, and this radiation can also drive energetic outflows. Mass ejection in the form of winds appears to be fundamental to quasar activity and can be directly observed in many objects with broadened and blue-shifted UV emission and absorption features. Dr. Gallagher will describe our model of the dusty wind and evaluate its successes and shortcomings in accounting for observed properties of quasars such their mid-infrared power and the fraction of hidden objects. Sarah Gallagher is currently an associate professor in the Department of Physics and Astronomy at the University of Western Ontario. Prior to that, she was an assistant research astronomer at the University of California, Los Angeles. Her research focuses on investigating the nature of winds from luminous quasars (accreting supermassive black holes at the centers of distant galaxies) using observatories covering the infrared to the X-ray, including two of NASA鈥檚 Great Observatories, Spitzer and Chandra.