Sridhar, S and Saini, Tarun Deep (2010) Slow m=1 instabilities of softened gravity Keplerian discs. In: Monthly Notices of the Royal Astronomical Society, 404 (1). pp. 527-531.Full text not available from this repository. (Request a copy)
We present the simplest model that permits a largely analytical exploration of the m =1 counter-rotating instability in a `hot' nearly Keplerian disc of collisionless self-gravitating matter. The model consists of a two-component softened gravity disc, whose linear modes are analysed using the Wentzel-Kramers-Brillouin approximation. The modes are slow in the sense that their (complex) frequency is smaller than the Keplerian orbital frequency by a factor which is of order the ratio of the disc mass to the mass of the central object. Very simple analytical expressions are derived for the precession frequencies and growth rates of local modes; it is shown that a nearly Keplerian discm must be unrealistically hot to avoid an overstability. Global modes are constructed for the case of zero net rotation.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to John Wiley and Sons.|
|Keywords:||instabilities;stellar dynamics;celestial mechanics;galaxies: nuclei|
|Date Deposited:||07 Jun 2010 06:48|
|Last Modified:||07 Jun 2010 06:48|
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