Satellite Infall and Mass Deposition on the Galactic Centre

TL;DR

This study models a satellite galaxy's infall into the Galactic Centre to assess its impact on gas dynamics, finding that such an event would not produce significant gas inflow or perturbations as previously hypothesized.

Contribution

The paper provides hydrodynamical simulations demonstrating that a satellite galaxy infall does not cause the large gas inflow needed to explain past black hole activity and star formation in the Galactic Centre.

Findings

Small gas inflow observed in simulations

Satellite infall insufficient to perturb gas significantly

Challenges previous hypotheses about gas dynamics in the Galactic Centre

Abstract

We model the infall of a 2e5 Msun satellite galaxy on to the inner 200 parsec of our Galaxy, to test whether the satellite could perturb the gas previously on stable orbits in the central molecular zone (CMZ), as proposed by Lang et al. (2013). This process would have driven a large gas inflow around 10 Myr ago, necessary to explain the past high accretion rate onto the super-massive black hole, and the presence of young stars in the inner parsecs of the Galaxy. Our hydrodynamical simulations show a much smaller inflow of gas, not sufficient to produce the aforementioned effects.