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

Abstract

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.

Authors:
;  [1];  [2];  [3]
  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)
Publication Date:
OSTI Identifier:
21378156
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 706; Journal Issue: 1; Other Information: DOI: 10.1088/0004-637X/706/1/705; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
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

Citation Formats

Henisey, Ken B, Blaes, Omer M, Fragile, P Chris, and Ferreira, Barbara T. EXCITATION OF TRAPPED WAVES IN SIMULATIONS OF TILTED BLACK HOLE ACCRETION DISKS WITH MAGNETOROTATIONAL TURBULENCE. United States: N. p., 2009. Web. doi:10.1088/0004-637X/706/1/705.
Henisey, Ken B, Blaes, Omer M, Fragile, P Chris, & Ferreira, Barbara T. EXCITATION OF TRAPPED WAVES IN SIMULATIONS OF TILTED BLACK HOLE ACCRETION DISKS WITH MAGNETOROTATIONAL TURBULENCE. United States. https://doi.org/10.1088/0004-637X/706/1/705
Henisey, Ken B, Blaes, Omer M, Fragile, P Chris, and Ferreira, Barbara T. 2009. "EXCITATION OF TRAPPED WAVES IN SIMULATIONS OF TILTED BLACK HOLE ACCRETION DISKS WITH MAGNETOROTATIONAL TURBULENCE". United States. https://doi.org/10.1088/0004-637X/706/1/705.
@article{osti_21378156,
title = {EXCITATION OF TRAPPED WAVES IN SIMULATIONS OF TILTED BLACK HOLE ACCRETION DISKS WITH MAGNETOROTATIONAL TURBULENCE},
author = {Henisey, Ken B and Blaes, Omer M and Fragile, P Chris and Ferreira, Barbara T},
abstractNote = {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.},
doi = {10.1088/0004-637X/706/1/705},
url = {https://www.osti.gov/biblio/21378156}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 706,
place = {United States},
year = {Fri Nov 20 00:00:00 EST 2009},
month = {Fri Nov 20 00:00:00 EST 2009}
}