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Statistical time-dependent model for the interstellar gasWe present models for temperature and ionization structure of low, uniform-density (approximately 0.3 per cu cm) 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, temperature, and their various observable moments. These time-dependent models predict a bimodal temperature distribution of the gas 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 (approximately 30 K), ionized (ionized fraction equal to about 0.1) regions.
Document ID
19740047290
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Gerola, H.
Kafatos, M.
(Joint Institute for Laboratory Astrophysics, Boulder, Colo.; NASA, Goddard Space Flight Center Greenbelt, Md., United States)
Mccray, R.
(Joint Institute for Laboratory Astrophysics; Colorado, University Boulder, Colo., United States)
Date Acquired
August 7, 2013
Publication Date
April 1, 1974
Publication Information
Publication: Astrophysical Journal
Volume: 189
Subject Category
Space Sciences
Accession Number
74A30040
Distribution Limits
Public
Copyright
Other

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