THERMAL INSTABILITIES IN INTERSTELLAR GAS HEATED BY COSMIC RAYS.
Abstract
The paper presents a theoretical study of therma instabilities in interstellar gas that is heated by cosmic rays. As a result of such instabilities, perturbations within the hot, rarefield intercloud medium can grow in magnitude and cause a transition to a dense, cool gas phase in pressure equilibrium with the intercloud phase. Analytic expressions give a growth rate from the linearized hydrodynamic equations, and a computer program follows the perturbations into the non-linear regime. The equations of constraint allow for changes in the ionization of the interstellar gas and for the presence of a magnetic field component perpendicular to the wave vector of the perturbation. The computer program was also used to study a one-dimensional spherical piston problem, as an approximation to the advance of a supernova shell into the initially homogeneous intercloud medium. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1969
- Accession Number
- AD0697670
Entities
People
- D. W. Goldsmith
Organizations
- Stanford University