Astronomy and Astrophysics – Astrophysics
Scientific paper
1994-10-18
Astronomy and Astrophysics
Astrophysics
11 pages PASP LaTeX, 5 figures upon request, invited paper at "The Physics of ISM and IGM", in honour of Prof. G.B. Field, ARC
Scientific paper
We study thermoreactive and acoustic instabilities in a diffuse gas, photoionized and heated by a radiation field. The analysis of the thermal instability by Field (1965) is extended to include the effects of the hydrogen recombination reaction, which, in general, is found to be a stabilizing agent for the condensation mode. This effect is stronger when the mean photon energy is not much larger than the hydrogen ionization energy. In addition, there are thermoreactive unstable equilibria for which an isobaric transition to a stable phase is not possible and the system evolves toward a dynamic state characterized by large amplitude, nonlinear periodic oscillations of temperature, density and hydrogen ionization fraction. Acoustic waves are found to be unstable for some temperatures of both the cold and the warm phase of the ISM, also in regions where the gas is {\it thermally stable}, independently of the mean photon energy.
Corbelli Edvige
Ferrara Andrea
No associations
LandOfFree
Acoustic and Thermoreactive Instabilities in a Photoionized Multiphase Medium does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Acoustic and Thermoreactive Instabilities in a Photoionized Multiphase Medium, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Acoustic and Thermoreactive Instabilities in a Photoionized Multiphase Medium will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-438721