Effects of gas on the global stability of galactic disks: Radial flows

Isaac Shlosman, Masafumi Noguchi

Research output: Contribution to journalArticlepeer-review

106 Citations (Scopus)


We study numerically the effect of gas on the global stability of a two-component self-gravitating galactic disk embedded in a live halo. The stars are evolved by using a three-dimensional collisionless N-body code, and the gas is represented by an ensemble of finite size inelastic particles. The gravitational interaction of stars and gas is calculated using a TREE method. We find that the evolution of the gaseous distribution in the globally unstable disks can be described by two different regimes. When the gas mass fraction is less than ∼10%, the gas is channeled toward the galactic center by a growing stellar bar. For higher gas fractions, the gas becomes highly inhomogeneous, and the bar instability in the disk is heavily damped. The gas falls toward the inner kpc due to dynamical friction. Domains of both regimes depend on the efficiency of dissipation in the gas. We also discuss the relevance of the Jeans instability and give an empirical criterion for the global bar instability in a two-component self-gravitating disk.

Original languageEnglish
Pages (from-to)474-486
Number of pages13
JournalAstrophysical Journal
Issue number2
Publication statusPublished - 1993 Sept 10
Externally publishedYes


  • Galaxies: Seyfert
  • Galaxies: evolution
  • Galaxies: kinematics and dynamics
  • Galaxies: structure
  • Hydrodynamics
  • Quasars

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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