Document Type
Article
Publication Date
1974
Abstract
We present models for temperature and ionization structure of low, uniform-density (n ~ 0.3 cm^-3) interstellar gas in a galactic disk which is exposed to soft X-rays from supernova outbursts occurring randomly in space and time. The structure was calculated by computing the time record of temperature and ionization at a given point by Monte Carlo simulation. The calculation yields probability distribution functions for ionized fraction x, temperature T, and their various observable moments. These time-dependent models predict a bimodal temperature distribution of the gas with structure in x, T that agrees with various observations. Cold regions in the low-density gas may have the appearance of clouds in 21-cm absorption. The time-dependent model, in contrast to the steady-state model, predicts large fluctuations in ionization rate and the existence of cold (T ~ 30° K), ionized (x ~ 0.1) regions.
Recommended Citation
Gerola, H., Kafatos, M., McCray, R. (1974) Statistical Time-Dependent Model for the Interstellar Gas, Astrophysical Journal, 189: 55-66. doi: 10.1086/152768
Peer Reviewed
1
Copyright
IOP Publishing
Included in
Atomic, Molecular and Optical Physics Commons, Stars, Interstellar Medium and the Galaxy Commons
Comments
This article was originally published in Astrophysical Journal, volume 189, in 1974. DOI: 10.1086/152768