1999/07/20 by M. Tagger, Tagger, M., R. Pellat +1
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #High-pressure geophysics and materials #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9907267
15 pages, 10 figures, to be published in A&A. single gzipped, tared file
arxiv created 1999/07/20 · openalex publication_date 1999/07/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present an instability occurring in the inner part of disks threaded by a moderately strong vertical (poloidal) magnetic field. Its mechanism is such that a spiral density wave in the disk, driven by magnetic stresses (rather than self-gravity as in galactic spirals), becomes unstable by exchanging angular momentum with a Rossby vortex it generates at its corotation radius. This angular momentum can then ``leak'' as Alfven waves emitted toward the corona of the disk thus providing, as an element of the accretion process, an energetic source for a wind or a jet. As galactic spirals, this instability forms low azimuthal wavenumber, standing spiral patterns which might provide an explanation for low-frequency QPOs in low-mass X-ray binaries.