Stellar distributions around supermassive black holes in gas-rich nuclear star clusters

TL;DR

This paper investigates how gas-rich environments around supermassive black holes influence stellar distributions, extending classical models to include gas drag effects and exploring implications for stellar interactions and transient events.

Contribution

It introduces a modified model of stellar distribution around SMBHs that incorporates gas drag, providing new insights into the dynamics in gas-rich nuclear star clusters.

Findings

Gas drag significantly alters stellar density profiles.

Modified models predict different rates of tidal disruption events.

Gas-rich environments impact stellar dynamics and transient phenomena.

Abstract

We study the stellar distribution around supermassive black holes (SMBHs) in gas-rich nuclear star clusters (NSCs). NSCs could contain vast amounts of gas, which contribute significantly to shaping the stellar distribution, typically altering the stellar density cusp from the usual Bahcall \& Wolf 1976 solution and consequently affecting the dynamics in the NSC. The dense gaseous environment in NSCs gives rise to dynamical phenomena that are otherwise rare in other gas-free environments. Here we extend the derivation introduced in Bahcall \& Wolf 1976 to include an additional energy dissipation term associated with gas drag. We examine the effect of different forms of gas drag on the stellar density distribution. Finally, we discuss implications on the rates of tidal disruption events and other transients triggered by stellar interactions in gas-rich galactic nuclei.