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Chemistry in Shocks

Published online by Cambridge University Press:  14 August 2015

T.W. Hartquist
T.W. Hartquist*
Affiliation:
Max-Planck-Institute for Physics and Astrophysics, Institute for Extraterrestrial Physics, 8046 Garching, Federal Republic of Germany

Abstract

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The column densities of interstellar CH+, first detected about fifty years ago, cannot be explained with models of the chemistry in low temperature gas. The resolution of this classic problem is necessary for us to have confidence in our understanding of interstellar chemistry and its role in determining the physical conditions in interstellar clouds and in the utility of molecular abundance measurements as diagnostics. The possibility that the observed CH+ is formed primarily in shocks in diffuse clouds is addressed. The way in which the chemistry affects the structure of such a diffuse cloud shock is also discussed. The analogous chemical influence on the structures of shocks in dense molecular clouds is also considered as is the possibility that gas in some dense molecular clouds passes repeatedly through dynamical cycles and is shocked frequently enough to influence the global chemical structures in those clouds. Some atomic and molecular data needs are mentioned.

Type
Joint Discussions
Information
Highlights of Astronomy , Volume 8: Highlights of Astronomy. As presented at the XXth General Assembly of the IAU, 1988 , 1989 , pp. 375 - 382
Copyright
Copyright © Kluwer 1989

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