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Full-Text Articles in Astrophysics and Astronomy
Ionization Of Carbon And Nitrogen In The Intercloud Medium, Menas Kafatos, H. Gerola, S. Hatchett, R. Mccray
Ionization Of Carbon And Nitrogen In The Intercloud Medium, Menas Kafatos, H. Gerola, S. Hatchett, R. Mccray
Mathematics, Physics, and Computer Science Faculty Articles and Research
If the intercloud medium in the solar neighborhood was suddenly ionized less than 106 years ago, the subsequent relaxation of the gas can account for the very low observed column density of C III and N III yet still leave a significant fraction ("'0.05) of ionized hydrogen and of C I in a cold (T ≈ 20° K) intercloud medium. The OAO-C Copernicus observations in the direction of X Sco are consistent with cosmic abundances and a uniform-density medium, except for C III whose predicted column density from the C m ionization zone surrounding the star is a factor ~1Q …
Statistical Time-Dependent Model For The Interstellar Gas, H. Gerola, Menas Kafatos, R. Mccray
Statistical Time-Dependent Model For The Interstellar Gas, H. Gerola, Menas Kafatos, R. Mccray
Mathematics, Physics, and Computer Science Faculty Articles and Research
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 …