Gaseous disks of spiral galaxies: Arms and rings Academic Article uri icon

abstract

  • An improved linear stability theory of small-amplitude oscillations of a self-gravitating, infinitesi-mally thin gaseous disk of spiral galaxies has been developed. It was shown that in the differentiallyrotating disks for nonaxisymmetric perturbations Toomre’s modified critical Q-parameter is largerthan the standard one. We use hydrodynamical simulations to test the validity of the modifiedlocal criterion.KEY WORDS Galaxies: kinematics and dynamics, structure–instabilities

publication date

  • January 1, 2001