Astronomy & Astrophysics Seminar: The First Optical Characterization of Tidal Disruption Events and Their Surprising Host Galaxy Preference

Abstract:

A star passing close to a super-massive black hole can be torn apart in a tidal disruption event (TDE). Such an event may be accompanied by an optical/UV flare, and can thus be used to study otherwise quiescent black holes. But such events are rare and almost no candidate flares have been convincingly identified in observations. I will present three TDE candidates we recently discovered using the Palomar Transient Factory. Analyzing their observed properties together with those of candidates from the literature, we unify them, for the first time, into a single class of transients on a continuous scale of spectral characteristics. In addition, we find that most TDE candidates in our sample occur in rare E+A hosts (interpreted as post-merger galaxies). This surprising result may hold important clues about the conditions favored by TDEs. Events similar to those we identified are now being discovered by various surveys at an increasing rate, allowing us to improve our characterization and understading of these intriguing transients.

Seminar Organizer: Prof. Rennan Barkana