Nicholas Stone

Tuesday, April 30, 2:30 PM

Phillips Auditorium

 Title: The Tidal Disruption of Stars by Supermassive Black Holes

Although quiescent supermassive black holes are ubiquitous in the universe, measuring their properties is quite challenging.  The tidal disruption of an unlucky star offers a rare window into the demographics of these slumbering giants.  I will present my theoretical research on the rates, dynamics, and accretion disks of tidal disruption events (TDEs), with a focus on the ways that TDEs are influenced by general relativistic phenomena and the interesting questions probed by TDE observations.  Specifically, I will discuss how TDEs can serve as electromagnetic signatures of black hole recoiling from anisotropic gravitational wave emission.  I will then explore a 20-year old error in the literature that has overestimated the luminosity of TDE flares.

Next, I will present SPH simulations suggesting a possible resolution to the open problem of debris circularization.  Finally, I will outline how supermassive black hole spin imprints itself into the light curves of tidal disruption flares, and how Lense-Thirring precession lets us draw interesting conclusions from the relativistic Swift 1644+57 TDE.  I will also speak about analogous phenomena in the tidal disruption of neutron stars, and a possible electromagnetic discriminant between short gamma ray bursts powered by the merger of two neutron stars and those powered by a neutron star-black hole merger.