Rayleigh adjustment of narrow barriers in protoplanetary discs
Författare
Summary, in English
Sharp density features in protoplanetary discs, for instance at the edge of a magnetically dead zone, have recently been proposed as effective barriers to slow down or even stop the problematically fast migration of planetary cores into their central star. Density features on a radial scale approaching the disc vertical scaleheight might not exist, however, since they could be Rayleigh (or more generally Solberg-Høiland) unstable. Stability must be checked explicitly in one-dimensional viscous accretion disc models because these instabilities are artificially eliminated in the process of reducing the full set of axisymmetric equations. The disc thermodynamics, via the entropy stratification, and its vertical structure also influence stability when sharp density features are present. We propose the concept of Rayleigh adjustment for viscous disc models: any density feature that violates Rayleigh stability (or its generalization) should be diffused radially by hydrodynamical turbulence on a dynamical time-scale, approaching marginal stability in a quasi-continuous manner.
Publiceringsår
2010
Språk
Engelska
Sidor
2436-2440
Publikation/Tidskrift/Serie
Monthly Notices of the Royal Astronomical Society
Volym
402
Issue
4
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Oxford University Press
Ämne
- Astronomy, Astrophysics and Cosmology
Nyckelord
- accretion accretion discs hydrodynamics instabilities planetary systems: formation planetary systems: protoplanetary discs
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1365-2966