Stellar-wind Fueled Accretion onto Sagittarius A* in the Presence of a Nuclear Star Cluster

TL;DR

This paper investigates how the nuclear star cluster influences stellar wind accretion onto Sagittarius A*, concluding that its gravitational effect is negligible on parsec scales, thus supporting previous models.

Contribution

It demonstrates that the gravitational potential of the nuclear star cluster has minimal impact on stellar wind accretion onto Sgr A* at parsec scales, validating earlier simulations.

Findings

NSC's gravitational influence is negligible on accretion flow at parsec scales

Validates previous models neglecting NSC effects

Supports the robustness of existing accretion simulations

Abstract

The Milky Way's Galactic Center hosts the black hole Sagittarius A* (Sgr A*), which provides us with a close-up view into supermassive black hole accretion and feedback. Recent works have shown that the winds from $\sim 30$ Wolf-Rayet (WR) stars orbiting Sgr A* at about 4 arcsec are important contributors to feeding the supermassive black hole. A nuclear star cluster (NSC) with a mass of several $10^6 \, \text{M}_\odot$, of which $10^6 \, \text{M}_\odot$ is within 1 pc, also surrounds Sgr A*. The NSC contributes to the gravitational potential in the Galactic Center, affecting the orbits of the WR stars and their stellar winds. In this work, we examine the effects that the NSC has on the accretion of these stellar winds onto Sgr A* which have previously been neglected. We find that, on the parsec scale, the effect from the gravitational potential of the NSC is negligible on the wind-fed accretion flow, validating the existing simulations used in the literature.