2000/01/31 by Charles F. Gammie, Jeremy Goodman, Gordon I. Ogilvie · 1 citation
Mathematics · Physics and Astronomy · #Amplitude #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Classical mechanics #Floquet theory #Image warping #Instability #Mathematics #Mechanics #Nonlinear system #Optics #Parametric statistics #Physics #Quantum mechanics #Rotational symmetry #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2000.03669.x
published as Mon.Not.Roy.Astron.Soc. 318 (2000) 1005 · 14 pages, 6 figures, revised version with appendix added, to be published in MNRAS
arxiv created 2000/05/11 · openalex publication_date 2000/11/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We consider the stability of warping modes in Keplerian discs. We find them to be parametrically unstable using two lines of attack, one based on three-mode couplings and the other on Floquet theory. We confirm the existence of the instability and investigate its non-linear development in three dimensions, via numerical experiment. The most rapidly growing non-axisymmetric disturbances are the most nearly axisymmetric (low-m) ones. Finally, we offer a simple, somewhat speculative model for the interaction of the parametric instability with the warp. We apply this model to the masing disc in NGC 4258 and show that, provided the warp is not forced too strongly, parametric instability can fix the amplitude of the warp.