Tidal Disruption Events: A New Black Hole Census


  Nicholas Stone  
The Hebrew University of Jerusalem

When unlucky stars pass too close to massive black holes, they are torn apart by tidal forces.  The return of bound, highly elliptical streams of stellar debris to pericenter creates a super-luminous flare, lasting for weeks to months, with a peak luminosity greater than almost all supernovae.  Once a theoretical curiosity, these tidal disruption events (TDEs) are discovered in ever-greater numbers by optical and X-ray surveys; in the near future, the Israeli ULTRASAT mission will find hundreds to thousands of them in the ultraviolet as well.  Our growing sample of TDEs, which currently number around one hundred, raise exciting prospects for measuring massive black hole demographics, namely mass and spin distributions.  I will discuss what has been done so far on this front, the primary theoretical uncertainties remaining, and will close by highlighting exciting recent discoveries of TDEs around elusive "intermediate-mass" black holes.