A unified model for tidal disruption events

TL;DR

This paper presents a unified model for tidal disruption events (TDEs) based on 3D simulations, showing how viewing angle influences observed spectral diversity across different TDE classes.

Contribution

The study introduces a comprehensive 3D general relativistic radiation magnetohydrodynamics simulation framework to explain TDE spectral diversity as a viewing-angle effect.

Findings

Optically thick outflows and relativistic jets are produced in TDEs.

The ratio of optical to X-ray flux depends on the inclination angle.

A unified model explains TDE spectral diversity through viewing-angle dependence.

Abstract

In the past few years wide-field optical and UV transient surveys as well as X-ray telescopes have allowed us to identify a few dozen candidate tidal disruption events (TDEs). While in theory the physical processes in TDEs are expected to be ubiquitous, a few distinct classes of TDEs have been observed. Some TDEs radiate mainly in NUV/optical while others produce prominent X-rays. Moreover, relativistic jets have been observed in only a handful of TDEs. This diversity might be related to the details of the super-Eddington accretion and emission physics relevant to TDE disks. In this Letter, we utilize novel three-dimensional general relativistic radiation magnetohydrodynamics simulations to study the super-Eddington compact disk phase expected in TDEs. Consistent with previous studies, geometrically thick disks, wide-angle optically-thick fast outflows and relativistic jets are produced. The outflow density and velocity depend sensitively on the inclination angle, and hence so does the reprocessing of emission produced from the inner disk. We then use Monte-Carlo radiative transfer to calculate the reprocessed spectra and find that that the observed ratio of optical to X-ray fluxes increases with increasing inclination angle. This naturally leads to a unified model for different classes of TDEs in which the spectral properties of the TDE depend mainly on the viewing-angle of the observer with respect to the orientation of the disk.