2006/02/13 by Phil Arras, Omer Blaes, Neal J. Turner · 5 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.1086/505966
published as Astrophys.J. 645 (2006) L65-L68 · 4 pages, 2 figures. submitted to apj
arxiv created 2006/02/13 · openalex publication_date 2006/06/21 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
Quasi-periodic oscillations (QPOs) in the X-ray light curves of accreting neutron star and black hole binaries have been widely interpreted as being due to standing wave modes in accretion disks. These disks are thought to be highly turbulent due to the magnetorotational instability (MRI). We study wave excitation by MRI turbulence in the shearing box geometry. We demonstrate that axisymmetric acoustic modes and radial epicyclic motions driven by MRI turbulence give rise to narrow, distinct peaks in the temporal power spectrum. Inertial waves, on the other hand, do not give rise to distinct peaks which rise significantly above the continuum noise spectrum set by MRI turbulence, even when the fluid motions are projected onto the eigenfunctions of the modes. This is a serious problem for QPO models based on inertial waves.