The ionization and thermal balances are considered for a gas that is
ionized by a dilute radiation field, taking into account the diffuse
ionizing radiation produced by the gas. A number of models are constructed
in which the electron temperature and the ionization of the elements H,
He, C, N, 0, Ne, and Mg are determined for optically thin and optically
thick gases ionized by ultraviolet synchrotron radiation under different
conditions. Conclusions are then drawn about the general characteristics
of ionization by synchrotron radiation. It is shown that, in an optically
thin gas, because of the insensitive frequency- dependence of synchrotron
radiation each element occupies a number of different stages of ionization
at any one point in the gas. It is also shown that in an optically thick
gas the heavy elements remain ionized to much greater distances from the
source than hydrogen and helium, and that the gas becomes thermally unstable
when H and He have become almost completely neutral.
In addition, observations of the emission -line intensities of the
Crab Nebula are compared with a model of this object. Considerable disagreement
exists between the observed and predicted intensities, and
possible reasons for the discrepancy are discussed.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/623809 |
| Date | 10 1900 |
| Creators | Williams, R. E. |
| Contributors | Univ Arizona, Steward Observ |
| Publisher | Steward Observatory, The University of Arizona (Tucson, Arizona) |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Article |
| Source | Steward Observatory Parker Library SO QB 4 .S752 ARCH |
| Rights | Copyright © All Rights Reserved. |
| Relation | Preprints of the Steward Observatory #2, http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1967ApJ...147..556W&db_key=AST&data_type=HTML&format=&high=3ed65e9cd001429 |
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