Varieties of Tidal Disruption Events

Taeho Ryu (MPA Garching).

Tidal disruption events (TDEs) are one of the most dramatic transients in which a star is tidally disrupted by a supermassive black hole, generating a flare luminous enough to outshine the entire host galaxy. Approximately 100 tidal disruption event candidates have been observed so far. In the near future, the number will grow dramatically with detections by the ongoing and upcoming surveys (e.g., eROSITA and LSST). The conventional picture has been that a star is fully disrupted at the first pericenter passage and the debris circularizes rapidly, forming a compact accretion disk. However, TDEs are more diverse and they can be categorized into several groups depending on stellar pericenter distance, from partial disruptions (i.e., partial mass loss and surviving remnant) to full disruptions which can be further sub-categorized depending on relativistic effects. TDEs of each class have qualitatively different outcomes and reveal very distinctive debris evolution, indicating different observational features. In this talk, I will briefly explain the physics behind TDEs and discuss the properties of the outcomes produced in TDEs of different classes, including a new class of the most relativistic observable events, and their observational implications, based on recent fully relativistic hydrodynamics simulations for TDEs.