Skip to main content
SearchLoginLogin or Signup

How warped accretion disks around black holes dramatically shift the standard accretion paradigm

Presentation #401.03 in the session Active Galactic Nuclei II.

Published onJul 01, 2023
How warped accretion disks around black holes dramatically shift the standard accretion paradigm

The infalling gas that eventually forms an accretion disk around a black hole has no prior knowledge of the black hole spin axis. Thus, most accretion disks will be at least initially misaligned with respect to the black hole spin axis. As the black hole rotates, it drags the surrounding space-time, inducing ‘Lense-Thirring’ torques which cause the disk to undergo precession and become warped. In some cases, these torques can cause the disk to tear apart into multiple, individually precessing sub-disks. These phenomena can drastically alter how angular momentum is transported in the disk. I will discuss recent simulations from my research group where we have performed (both radiative and non-radiative) general-relativistic magnetohydrodynamic simulations of thin, highly tilted accretion disks around rapidly rotating black holes. In particular, I will present novel dissipation mechanisms unique to these systems that drive accretion on timescales much shorter than the usual viscous time. I will discuss the potential applications of these results to recent observations of extreme variability in active galactic nuclei. Time permitting, I will discuss how the radiation pressure instability that thin Shakura-Sunyaev disks are subject to is modified in warped disks.

Comments
0
comment
No comments here