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- Andersson, Stefan, 1973, et al.
(author)
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Rotational Transitions of CO+ Induced by Atomic Hydrogen
- 2008
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In: The Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 678, s. 1042-1048
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Journal article (peer-reviewed)abstract
- The CO+ molecular ion has been observed in photon-dominated regions. Recent modeling has not been able to explain the abundances of CO+ in these regions. The most abundant collision partners are believed to be hydrogen atoms, hydrogen molecules, and electrons. The reactions of these species with CO+ have been studied previously and found to be fast. The only inelastic processes studied before were collisions of CO+ with electrons. Here we investigate the inelastic collisions of CO+ with hydrogen atoms. We argue that this can be done on the lowest triplet electronic state. This implies that CO+ ions, in a hydrogen atom dominated surrounding, experiences a few inelastic collisions before reacting. Rotationally inelastic state-to-state cross sections ( ) are presented together with state-resolved thermal rate coefficients. The results suggest that the rotationally inelastic collision cross sections can be of comparable magnitude to the reactive ones. Implications for the rotational temperature of CO+ in PDRs are discussed. To perform the calculations, a potential energy surface is fitted using the reproducing-kernel Hilbert space method based on multireference configuration-interaction calculations employing the aug-cc-pVQZ basis set.
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