The hyperfine excitation of OH radicals by He*
1 Department of Chemistry and
Biochemistry, School of Biological and Chemical Sciences, Queen Mary University of
London, Joseph Priestley Building,
Mile End Road, London
2 LOMC – UMR 6294, CNRS-Université du Havre 25 rue Philippe Lebon, BP 1123, 76063, Le Havre, France
3 Tomsk State University, 36 Lenin av., 634050 Tomsk, Russia
a e-mail: firstname.lastname@example.org
Received in final form: 3 March 2016
Published online: 21 April 2016
Hyperfine-resolved collisions between OH radicals and He atoms are investigated using quantum scattering calculations and the most recent ab initio potential energy surface, which explicitly takes into account the OH vibrational motion. Such collisions play an important role in astrophysics, in particular in the modelling of OH masers. The hyperfine-resolved collision cross sections are calculated for collision energies up to 2500 cm-1 from the nuclear spin free scattering S-matrices using a recoupling technique. The collisional hyperfine propensities observed are discussed. As expected, the results from our work suggest that there is a propensity for collisions with ΔF = Δj. The new OH−He hyperfine cross sections are expected to significantly help in the modelling of OH masers from current and future astronomical observations.
© The Author(s) 2016. This article is published with open access at Springerlink.com
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