Inertial waves near corotation in 3D hydrodynamical disks

Abstract

This paper concerns the interaction between non-axisymmetric inertial waves and their corotation resonances in a hydrodynamical disk. Inertial waves are of interest because they can localise in resonant cavities circumscribed by Lindblad radii, and as a consequence exhibit discrete oscillation frequencies that may be observed. It is often hypothesised that these trapped eigenmodes are affiliated with the poorly understood QPO phenomenon. We demonstrate that a large class of non-axisymmetric 3D inertial waves cannot manifest as trapped normal modes. This class includes any inertial wave whose resonant cavity contains a corotation singularity. Instead, these `singular' modes constitute a continuous spectrum and, as an ensemble, are convected with the flow, giving rise to shearing waves. Lastly, we present a simple demonstration of how the corotation singularity stabilizes three-dimensional perturbations in a slender torus.

17 pages, 5 figures. MNRAS accepted. V2 - Section 5.2 moved to appendix and errors removed

References in corpus (6)

• Three Dimensional Compressible Hydrodynamic Simulations of Vortices in Disks
• On the time variability of geometrically-thin black hole accretion disks I : the search for modes in simulated disks
• An Exact, Three-Dimensional, Time-Dependent Wave Solution in Local Keplerian Flow
• On an excitation mechanism for trapped inertial waves in discs around black holes
• Quasi-Periodic Oscillations from Magnetorotational Turbulence
• Hydrodynamic response of rotationally supported flows in the Small Shearing Box model

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