Details

Autor(en) / Beteiligte

• Lovelace, R. V. E.
• Hohlfeld, R. G.

Titel

Rossby wave instability with self-gravity

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2013-02, Vol.429 (1), p.529-533

Ort / Verlag

London: Oxford University Press

Erscheinungsjahr

2013

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The Rossby wave instability (RWI) in non-self-gravitating discs can be triggered by a bump at a radius r 0 in the disc surface mass density (which is proportional to the inverse potential vorticity). It gives rise to a growing non-axisymmetric perturbation [∝exp (imφ), m = 1, 2 ...] in the vicinity of r 0 consisting of anticyclonic vortices which may facilitate planetesimal growth in protoplanetary discs. Here, we analyse a continuum of thin disc models ranging from self-gravitating to non-self-gravitating. The key quantities determining the stability/instability are (1) the parameters of the bump (or depression) in the disc surface density, (2) the Toomre Q parameter of the disc (a non-self-gravitating disc has Q > 1) and (3) the dimensionless azimuthal wavenumber of the perturbation , where h is the half-thickness of the disc. For discs stable to axisymmetric perturbations (Q > 1), the self-gravity has a significant role for or m < (π/2)(r 0/h)Q − 1; instability may occur for a depression or groove in the surface density if Q 2. For \pi /2$]]> the self-gravity is not important, and instability may occur at a bump in the surface density. Thus, for all mode numbers m ≥ 1, the self-gravity is unimportant for Q > (π/2)(r 0/h). We suggest that the self-gravity be included in simulations for cases where Q < (r 0/h).