On the stability of self-gravitating accreting flows

TL;DR

This paper numerically investigates the stability of self-gravitating, transonic accretion flows onto compact objects, finding they are generally stable and exploring the analogy between sonic and event horizons.

Contribution

It provides the first numerical analysis of the stability of self-gravitating accretion flows and examines the sonic horizon analogy under finite perturbations.

Findings

Self-gravitating flows are numerically stable.

The sonic horizon analogy holds for small perturbations.

The analogy fails for finite perturbations.

Abstract

Analytic methods show stability of the stationary accretion of test fluids but they are inconclusive in the case of self-gravitating stationary flows. We investigate numerically stability of those stationary flows onto compact objects that are transonic and rich in gas. In all studied examples solutions appear stable. Numerical investigation suggests also that the analogy between sonic and event horizons holds for small perturbations of compact support but fails in the case of finite perturbations.