The late flare in tidal disruption events due to the interaction of disk wind with dusty torus

TL;DR

This paper models a late-time flare in a tidal disruption event caused by the interaction of disk wind with a dusty torus, providing insights into the nuclear environment of active galactic nuclei.

Contribution

It introduces a novel scenario linking late TDE flares to disk wind and dusty torus interactions, supported by detailed dynamics and radiation modeling.

Findings

Disk wind has kinetic energy ~10^51 erg and velocity ~0.1c.

The torus gas density is estimated at 3×10^7 cm^-3.

Model matches the observed late flare in PS1-10adi.

Abstract

A late (t $\sim$ 1,500 days) multi-wavelength (UV, optical, IR, and X-ray) flare was found in PS1-10adi, a tidal disruption event (TDE) candidate that took place in an active galactic nucleus (AGN). TDEs usually involve super-Eddington accretion, which drives fast mass outflow (disk wind). So here we explore a possible scenario that such a flare might be produced by the interaction of the disk wind with a dusty torus for TDEs in AGN. Due to the high velocity of the disk wind, strong shocks will emerge and convert the bulk of the kinetic energy of the disk wind to radiation. We calculate the dynamics and then predict the associated radiation signatures, taking into account the widths of the wind and torus. We compare our model with the bolometric light curve of the late flare in PS1-10adi constructed from observations. We find from our modeling that the disk wind has a total kinetic energy of about $10^{51}$ erg and a velocity of 0.1 c (i.e., a mass of 0.3 $M_{\odot}$); the gas number density of the clouds in the torus is $3\times 10^{7}$ $\rm cm^{-3}$. Observation of such a late flare can be an evidence of the disk wind in TDEs and can be used as a tool to explore the nuclear environment of the host.