Relativistic Bondi-Hoyle-Lyttleton Accretion onto a Rotating Black Hole: Density Gradients
Abstract
In this work, for the first time, we present a numerical study of Bondi-Hoyle accretion with density gradients in the fully relativistic regime. In this context, we consider the accretion onto a Kerr black hole (BH) of a supersonic ideal gas with density gradients perpendicular to the relative motion. The parameters of interest in this study are the Mach number, {M}, the spin of the BH, a, and the density-gradient parameter of the gas, ɛρ. We show that, unlike in the Newtonian case, all of the studied cases, especially those with a density gradient, approach a stationary flow pattern. To illustrate that the system reaches a steady state, we calculate the mass and angular momentum accretion rates on a spherical surface almost located at the event horizon. In the particular case of {M}=1, ɛρ = 0.5, and BH spin a = 0.5, we observe a disk-like configuration surrounding the BH. Finally, we present the gas morphology and some of its properties.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- August 2015
- DOI:
- 10.1088/0067-0049/219/2/30
- arXiv:
- arXiv:1506.08713
- Bibcode:
- 2015ApJS..219...30L
- Keywords:
-
- accretion;
- accretion disks;
- black hole physics;
- hydrodynamics;
- methods: numerical;
- relativistic processes;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 14 pages, 60 png figures, 1 table. Accepted for publication in the Astrophysical Journal Supplement