SMBH in Galactic Nuclei with Tidal Disruption of Stars

TL;DR

This study uses high-accuracy N-body simulations to analyze the tidal disruption of stars by supermassive black holes in galactic nuclei, examining disruption rates, stellar density changes, and the origins of disrupted stars.

Contribution

It provides the first detailed numerical support for the critical radius concept and explores the transition from full to empty loss-cone regimes in star clusters.

Findings

Disruption rate scales with particle number as expected.

Supports the critical radius concept of Frank & Rees (1976).

Finds velocity anisotropy inside the cluster due to star consumption.

Abstract

Tidal Disruption of stars by super massive central black holes from dense star clusters is modeled by high-accuracy direct $N$-body simulation. The time evolution of the stellar tidal disruption rate, the effect of tidal disruption on the stellar density profile and for the first time the detailed origin of tidally disrupted stars are carefully examined and compared with classic papers in the field. Up to 128k particles are used in simulation to model the star cluster around the super massive black hole, we use the particle number and the tidal radius of black hole as free parameters for a scaling analysis. The transition from full to empty loss-cone is analyzed in our data, the tidal disruption rate scales with the particle number $N$ in the expected way for both cases. For the first time in numerical simulations (under certain conditions) we can support the concept of a critical radius of Frank & Rees (1976), which claims that most stars are tidally accreted on highly eccentric orbits originating from regions far outside the tidal radius. Due to the consumption of stars moving on radial orbits, a velocity anisotropy is founded inside the cluster. Finally we make an estimation for the real galactic center based on our simulation results and the scaling analysis.