Cosmic ray moderation of the thermal instability

A. Y. Wagner, S. A. E. G. Falle, T. W. Hartquist, J. M. Pittard
2005 Astronomy and Astrophysics  
We apply the Hermite-Bieler theorem in the analysis of the effect of cosmic rays on the thermal stability of an initially uniform, static background. The cosmic rays were treated in a fluid approximation and the diffusion coefficient was assumed to be constant in time and space. The inclusion of cosmic rays does not alter the criterion for the thermal stability of a medium subjected to isobaric perturbations. It does alter the criteria for the stability of a medium perturbed by small amplitude
more » ... ound waves. In the limit of a high background cosmic ray pressure to thermal pressure ratio, the instability in response to high frequency sound waves is suppressed.
doi:10.1051/0004-6361:20042138 fatcat:on6ebtkxh5fslhrk743gfdlejy