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H3+: the initiator of interstellar chemistry

Published online by Cambridge University Press:  07 August 2008

Mats Larsson
Mats Larsson
Affiliation:
Department of Physics, AlbaNova University Center, Stockholm University, SE-10691 Stockholm, Sweden e-mail: [email protected]
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Abstract

Second only to H2, protonated molecular hydrogen, H3+, is the most abundantly produced interstellar molecule. Owing to its high reactivity and acidity, it plays the pivotal role in initiating interstellar chemical reactions, something which also reduces its steady-state concentration. Interstellar H3+ is not only destroyed in chemical reactions but also in dissociative recombination with electrons. The rate constant and mechanism of recombination have long been controversial, but great advances have been made during recent years, with the important consequence that the cosmic ray ionization rate in diffuse clouds is now believed to be higher by an order of magnitude than previously assumed.

Keywords

dissociative recombinationinterstellar chemistrycosmic rayionization rate
Type
Research Article
Information
International Journal of Astrobiology , Volume 7 , Issue 3-4 , October 2008 , pp. 237 - 241
Copyright
Copyright © 2008 Cambridge University Press

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