The Variety of Tidal Disruption Events

Tsvi Piran (Racah Institute for Physics)

August 15, 2022

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Abstract: Tidal disruption events (TDEs), in which a star is torn apart by a giant black hole at a galactic center may have very different appearances. The observational signature of the TDE is determined by the energy dissipation of the debris. I will show that this depends, in turn, on the trajectory of the debris which is largely determined by the pericenter distance of the orbit of the disrupted star. First, I will explore the main three types of TDEs which I call: Circularized, Common and Partial. Then I will discuss Extreme TDEs, a new type of events that arise when the pericenter passage is very close to the black hole horizon. In Extreme TDEs general relativistic effects that have not been seen before shape the debris orbit leading to an observational signature that is very different from most TDEs. Finally, I will explore environmental effects and discuss the fate of a TDE around an AGN in which an accretion disk rotates around the black hole. Here the interaction between the debris and the disk dominates the energy dissipation process. The resulting signal is, once more, very different from the one of regular TDEs.