Branching ratio for O + H+3 forming OH+ + H2 and H2O+ + H
(2022) The Astrophysical Journal — Vol. 927, n° 1, p. 47 (2022)
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- Authors
Hillenbrand, Pierre-Michel 
Ruette, Nathalie de Savin, Daniel W.
- Abstract
- The gas-phase reaction of O+H+3 has two exothermic product channels, OH+8 +H2 and H2O++H. In the present study, we analyze experimental data from a merged-beams measurement to derive thermal rate coe_cients resolved by product channel for the temperature range from 10 to 1000 K. Published astrochemical models either ignore the second product channel or apply a temperature-independent branching ratio of 70% vs. 30% for the formation of OH+ 12 + H2 vs. H2O+ + H, respectively, which originates from a single experimental data point measured at 295 K. Our results are consistent with this data point, but show a branching ratio that varies with temperature reaching 58% vs. 42% at 10 K. We provide recommended rate coe_cients for the two product channels for two cases, one where the initial _ne-structure population of the O(3PJ ) reactant is in its J = 2 ground state and the other one where it is in thermal equilibrium.
- Affiliations
Citations
Hillenbrand, P.-M., Ruette, N. d., Urbain, X., & Savin, D. W. (2022). Branching ratio for O + H+3 forming OH+ + H2 and H2O+ + H. The Astrophysical Journal, 927(1), 47. https://doi.org/10.3847/1538-4357/ac41ce (Original work published 2022)