Thu, September 07, 2017
"Hunting for Black Holes"
Black holes come in at least two varieties – small stellar-mass black holes and supermassive black holes. The stellar-mass black holes are predicted to form when a massive star dies in a violent supernova explosion. There should be 100 million to 1 billion of these star-sized black holes in our Galaxy; but this number is uncertain by an order of magnitude. The ~25 stellar-mass black holes we have found so far are all in binary systems with a companion star that is dumping hot gas onto the black hole, causing it to glow and flicker in X-rays. Even the recent LIGO discovery of gravitational waves emanated from a binary black hole. Where are all of the isolated black holes? I will present our prospects for finding isolated “free-floating” black holes by using the technique of gravitational lensing. To find the first free-floating black hole, we will need high-resolution infrared images such as those delivered by laser-guided adaptive optics systems on the W. M. Keck Observatory and the future large ground-based telescopes.
Jessica Lu’s research focuses on black holes, star and cluster formation, galactic centers, and adaptive optics instrumentation. She grew up in Houston, TX where she attended the High School for Performing and Visual Arts with a major in dance. She later received her undergraduate degree in physics from the MIT. She worked as a software engineer in silicon valley for 3 years before returning to academia to pursue her PhD in astronomy and astrophysics at UCLA. After completing her PhD, she was awarded a Millikan Postdoctoral Fellowship at Caltech and an NSF Astronomy and Astrophysics postdoctoral fellowship at the Institute for Astronomy (IfA) in the University of Hawaii, Manoa where she became a faculty member in 2013. In the summer of 2016, Jessica joined the faculty of the UC Berkeley astronomy department.