{ "id": "1010.6189", "version": "v1", "published": "2010-10-29T12:18:46.000Z", "updated": "2010-10-29T12:18:46.000Z", "title": "Trapped, Two-Armed, Nearly Vertical Oscillations in Disks with Toroidal Magnetic Fields", "authors": [ "Shoji Kato" ], "comment": "18 pages, 6 figures, accepted PASJ 63, No.1 (2011)", "categories": [ "astro-ph.HE" ], "abstract": "We have examined trapping of two-armed ($m=2$) nearly vertical oscillations (vertical p-mode) in vertically isothermal ($c_{\\rm s}=$ const.) relativistic disks with toroidal magnetic fields. The magnetic fields are stratified so that the Alfv{\\'e}n speed, $c_{\\rm A}$, is constant in the vertical direction. The ratio of $c_{\\rm A}^2/c_{\\rm s}^2$ in the vertical direction is taken as a parameter examining the effects of magnetic fields on wave trapping. We find that the two-armed nearly vertical oscillations are trapped in the inner region of disks and their frequencies decrease with increase of $c_{\\rm A}^2/c_{\\rm s}^2$. The trapped regions of the fundamental ($n=1$) and the first-overtone ($n=2$) are narrow (less than the length of the Schwarzschild radius, $r_{\\rm g}$) and their frequencies are relatively high (on the order of the angular frequency of disk rotation in the inner region). On contrast to this, the second-overtone ($n=3$) are trapped in a wide region (a few times $r_{\\rm g}$), and their frequencies are low and tend to zero in the limit of $c_{\\rm A}^2/c_{\\rm s}^2=2.0$.", "revisions": [ { "version": "v1", "updated": "2010-10-29T12:18:46.000Z" } ], "analyses": { "keywords": [ "toroidal magnetic fields", "vertical oscillations", "inner region", "vertical direction", "relativistic disks" ], "tags": [ "journal article" ], "publication": { "doi": "10.1093/pasj/63.1.125", "journal": "Publications of the Astronomical Society of Japan", "year": 2011, "month": "Feb", "volume": 63, "pages": 125 }, "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable", "inspire": 874998, "adsabs": "2011PASJ...63..125K" } } }