Choked accretion onto a Kerr black hole

TL;DR

This paper extends the choked accretion model to rotating Kerr black holes, demonstrating through analytic and numerical methods that the inflow-outflow structure persists regardless of the black hole's spin, highlighting the model's robustness.

Contribution

It generalizes previous non-rotating models by incorporating black hole spin effects using analytic solutions and hydrodynamical simulations.

Findings

The inflow-outflow morphology remains stable for all black hole spins.

Rotation does not disrupt the choked accretion mechanism.

The model's robustness is confirmed across different equations of state.

Abstract

The choked accretion model consists of a purely hydrodynamical mechanism in which, by setting an equatorial to polar density contrast, a spherically symmetric accretion flow transitions to an inflow-outflow configuration. This scenario has been studied in the case of a (non-rotating) Schwarzschild black hole as central accretor, as well as in the non-relativistic limit. In this article, we generalize these previous works by studying the accretion of a perfect fluid onto a (rotating) Kerr black hole. We first describe the mechanism by using a steady-state, irrotational analytic solution of an ultrarelativistic perfect fluid, obeying a stiff equation of state. We then use hydrodynamical numerical simulations in order to explore a more general equation of state. Analyzing the effects of the black hole's rotation on the flow, we find in particular that the choked accretion inflow-outflow morphology prevails for all possible values of the black hole's spin parameter, showing the robustness of the model.