Nonlinear outcome of gravitational instability in cooling, gaseous disks

Research output: Contribution to journalArticle

Abstract

Thin, Keplerian accretion disks genetically become gravitationally unstable at large radii. I investigate the nonlinear outcome of such instability in cool disks using razor-thin, local, numerical models. Cooling, characterized by a constant cooling time τc, drives the instability. I show analytically that if the disk can reach a steady state in which heating by dissipation of turbulence balances cooling, then the dimensionless angular momentum flux density α = [(9/4)γ(γ - 1)Ωτc]-1. Numerical experiments show that (1) if τc ≳ 3Ω-1 then the disk reaches a steady, gravitoturbulent state in which Q ∼ 1 and cooling is balanced by heating due to dissipation of turbulence; (2) if τc ≲ 3Ω-11, then the disk fragments, possibly forming planets or stars; (3) in a steady, gravitoturbulent state, surface density structures have a characteristic physical scale ∼64GΣ/Ω2 that is independent of the size of the computational domain.

Original languageEnglish (US)
Pages (from-to)174-183
Number of pages10
JournalAstrophysical Journal
Volume553
Issue number1 PART 1
DOIs
StatePublished - May 20 2001

Keywords

  • Accretion, accretion disks
  • Galaxies: Nuclei
  • Solar system: Formation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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