Sur l'instabilité gravitationnelle d'un cylindre compressible

Abstract

This paper presents a numerical study of gravitational instability in a compressible fluid cylinder of infinite length, with respect to linear, adiabatic and axisymetrical normal modes. It is found that these modes are unstable, and that a mode of maximum instability does exist at a wave-length comparable with the diameter of the cylinder. Moreover, the numerical analysis suggests that all wave-lengths are indeed unstable : i.e., there seems to be no marginal mode (no critical wave-length) ; a conclusion which can be corroborated by an analytical discussion.