The Radiation (Magneto-)Hydrodyamics of Tidal Disruption Events

Transient surveys and follow up efforts are providing a wealth of new data on the variety of ways in which tidal disruption events manifest across the electromagnetic spectrum. Understanding these light curves and spectra are key to using these systems as probes of the black hole spacetime and as laboratories for understanding accretion more generally. I will present results from recent research by myself and collaborators to study the disruption and fallback accretion during tidal disruption events. Using the state-of-the-art Athena++ and AthenaK codes, we solve the radiation transfer equation to accurately model the radiation forces, which play a key role in these sources that commonly reach super-Eddington fallback rates. I will particularly highlight our most recent results, which solve the relevant equations in the Kerr spacetime. We find that even though the flows are slow to circularize, shocks between the infalling stream and either the returning stream or the eccentric disk that forms dominate the early energy release and angular momentum transport. Radiation forces drive both unbound outflows and generate an envelope of weakly bound material that acts as a reprocessing layer, potentially explaining the prevalence of optical/ultraviolet emission seen in many sources.