EXCITATION OF TRAPPED WAVES IN SIMULATIONS OF TILTED BLACK HOLE ACCRETION DISKS WITH MAGNETOROTATIONAL TURBULENCE

Journal Article · Fri Nov 20 00:00:00 EST 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/706/1/705· OSTI ID:21378156

Henisey, Ken B; Blaes, Omer M ^[1]; Fragile, P Chris ^[2]; Ferreira, Barbara T ^[3]

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1. Department of Physics, University of California, Santa Barbara, CA 93106 (United States)
2. Department of Physics and Astronomy, College of Charleston, Charleston, SC 29424 (United States)
3. Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

We analyze the time dependence of fluid variables in general relativistic, magnetohydrodynamic simulations of accretion flows onto a black hole with dimensionless spin parameter a/M = 0.9. We consider both the cases where the angular momentum of the accretion material is aligned with the black hole spin axis (an untilted flow) and where it is misaligned by 15 deg. (a tilted flow). In comparison to the untilted simulation, the tilted simulation exhibits a clear excess of inertial variability, that is, variability at frequencies below the local radial epicyclic frequency. We further study the radial structure of this inertial-like power by focusing on a radially extended band at 118(M/10 M{sub sun}){sup -1} Hz found in each of the three analyzed fluid variables. The three-dimensional density structure at this frequency suggests that the power is a composite oscillation whose dominant components are an over dense clump corotating with the background flow, a low-order inertial wave, and a low-order inertial-acoustic wave. Our results provide preliminary confirmation of earlier suggestions that disk tilt can be an important excitation mechanism for inertial waves.

• OSTI ID: 21378156
• Journal Information: Astrophysical Journal, Vol. 706, Issue 1; Other Information: DOI: 10.1088/0004-637X/706/1/705; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCRETION DISKS
BLACK HOLES
MAGNETOHYDRODYNAMICS
RELATIVISTIC RANGE
SIMULATION
SOUND WAVES
SPIN
TIME DEPENDENCE
TURBULENCE
X RADIATION
ANGULAR MOMENTUM
ELECTROMAGNETIC RADIATION
ENERGY RANGE
FLUID MECHANICS
HYDRODYNAMICS
IONIZING RADIATIONS
MECHANICS
PARTICLE PROPERTIES
RADIATIONS