Hydrodynamical simulation of wind production from hot accretion flows in tidal disruption events

TL;DR

This study uses hydrodynamical simulations to explore wind properties in tidal disruption events, revealing how black hole mass and viscosity influence wind speed and energy, with implications for galaxy feedback and black hole detection.

Contribution

It provides new insights into wind dynamics in TDEs, highlighting the effects of black hole mass, viscosity, and debris temperature on wind characteristics, differing from AGN and X-ray binary winds.

Findings

More massive black holes produce faster winds.

Unbound winds reach ~0.1c and carry ~10^{-4} L_Edd in kinetic energy.

Convective bound outflows dominate at lower viscosity, contrasting with typical AGN winds.

Abstract

Wind is a key mechanism for supermassive black hole (SMBH) feedback to their host galaxies. In tidal disruption events (TDEs), black holes spend most of their time accreting at highly sub-Eddington rates, implying that feedback from persistent sub-Eddington winds could be significant. We investigate the effects of black hole mass, viscosity parameter and stellar debris temperature on the properties of winds from hot accretion flows in TDEs. We find that more massive black holes yield a higher accreted fraction and launch faster winds, while the debris temperature has a negligible influence on the accretion flow. For $\alpha=0.1$, the mildly-relativistic unbound winds ($\sim 0.1c$) are launched predominantly from the outside of the accretion flows along the equatorial plane, with a kinetic energy of $\sim10^{-4}L_\mathrm{Edd}$. In contrast, convective bound outflows dominate for $\alpha=0.01$, which differs from the true winds typically seen in active galactic nuclei and X-ray binaries. Potential applications for explaining delayed radio brightening in TDEs at $\sim10^3$ days and for searching for intermediate-mass black holes through radio and X-ray surveys are also discussed.