Towards a Physical Understanding of Tidal Disruption Events

Coordinators: Kate Alexander, Eric Coughlin, Decker French, Suvi Gezari, and Chris Nixon

A tidal disruption event (TDE) occurs when a star is pulled apart by the gravitational field of a supermassive black hole (SMBH), transforming the star into a stream of stellar debris. In a matter of months, a fraction of this debris stream returns to the SMBH and ignites an accretion flare in the nucleus of the galaxy where it resides. TDEs have been observed in great detail across the electromagnetic spectrum; from the initial rise in flux to the decay back to quiescence. Such observations may enable an inference of the SMBH and disrupted star properties, while also providing a unique window into poorly understood aspects of accretion theory, such as the nature of super-Eddington flows and the production of jets and outflows.

The large increase in observational data for TDEs will provide an unprecedented census of the low-mass end of the SMBH population, but to take full advantage of this influx of data, we need robust and predictive theoretical models for the radiation from these events. We expect significant progress to arise from understanding the range of events that can be generated from the tidal disruption of stars, including quasi-periodic eruptions (QPEs). The goal of this program is to bring theorists and observers together to answer some of the most pressing questions on the physics of TDEs. From the processes that generate stars on fateful orbits toward the SMBH, to the initial destruction of the star and the formation of an accretion flow, to the production of high-energy radiation and outflows, this program aims to test, revise and extend our current understanding of TDEs and related phenomena.