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arXiv · 1304.4804

Rotational quenching of H2CO by molecular hydrogen: cross-sections, rates, pressure broadening

Laurent Wiesenfeld·Alexandre Faure
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Abstract

We compute the rotational quenching rates of the first 81 rotational levels of ortho- and para-H2CO in collision with ortho- and para-H2, for a temperature range of 10-300 K. We make use of the quantum close-coupling and coupled-states scattering methods combined with the high accuracy potential energy surface of Troscompt et al. (2009a). Rates are significantly different from the scaled rates of H2CO in collision with He; consequently, critical densities are noticeably lower. We compare a full close- coupling computation of pressure broadening cross sections with experimental data and show that our results are compatible with the low temperature measurements of Mengel & De Lucia (2000), for a spin temperature of H2 around 50 K.

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Laurent Wiesenfeld, Alexandre Faure. 2013-04-24. Rotational quenching of H2CO by molecular hydrogen: cross-sections, rates, pressure broadening. https://doi.org/10.1093/mnras%2Fstt616

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