Thick disk accretion in Kerr space-time with arbitrary spin parameters

TL;DR

This study investigates how finite angular momentum in accreting fluids affects the formation of equatorial outflows around Kerr black holes and super-spinars through advanced hydrodynamic simulations.

Contribution

It extends previous spherically symmetric accretion models to include angular momentum, revealing the critical role of fluid rotation in outflow formation around super-spinars.

Findings

Corotating disks efficiently produce equatorial outflows.

Counterrotating disks suppress outflows, limited to specific conditions.

Outflow strength depends on spin parameters and disk orientation.

Abstract

In this paper we extend our previous works on spherically symmetric accretion onto black holes and super-spinars to the case in which the fluid has a finite angular momentum initially. We run 2.5D and 3D general relativistic hydrodynamic simulations of the accretion of a fat disk. We study how the accretion process changes by changing the values of the parameters of our model. We show that the value of the fluid angular momentum critically determines turn-on and off the production of powerful equatorial outflows around super-spinars. For corotating disks, equatorial outflows are efficiently generated, even for relatively low spin parameters or relatively large super-spinar radii. For counterrotating disks, equatorial outflows are instead significantly suppressed, and they are possible only in limited cases. We also study accretion around a tilted disk.