Shock-induced Partial Alignment in Geometrically Thick Tilted Accretion Disks Around Black Holes Journal Article uri icon

Overview

abstract

  • Abstract; We carry out idealized three-dimensional general-relativistic magnetohydrodynamic simulations of prograde, weakly magnetized, and geometrically thick accretion flows where the gas distribution is misaligned from the black hole (BH) spin axis. We evolve the disk for three BH spins: a = 0.5, 0.75, and 0.9375, and we contrast them with a standard aligned disk simulation with a = 0.9375. The tilted disks achieve a warped and twisted steady-state structure, with the outer disk misaligning further away from the BH and surpassing the initial 24° misalignment. However, closer to the BH, there is evidence of partial alignment, as the inclination angle decreases with radius in this regime. Standing shocks also emerged in proximity to the BH, roughly at ∼6 gravitational radii. We show that these shocks act to partially align the inner disk with the BH spin. The rate of alignment increases with increasing BH spin magnitude, but in all cases is insufficient to fully align the gas before it accretes. Additionally, we present a toy model of orbit crowding that can predict the location of the shocks in moderate-to-fast rotating BHs, illustrating a potential physical origin for the behavior seen in simulations—with possible applications in determining the positions of shocks in real misaligned astrophysical systems.

publication date

  • October 1, 2024

has restriction

  • gold

Date in CU Experts

  • October 16, 2024 10:47 AM

Full Author List

  • Gupta S; Dexter J

author count

  • 2

Other Profiles

International Standard Serial Number (ISSN)

  • 0004-637X

Electronic International Standard Serial Number (EISSN)

  • 1538-4357

Additional Document Info

start page

  • 209

end page

  • 209

volume

  • 974

issue

  • 2