Communication: State-to-state inelastic scattering of interstellar O2 with H2
| Autor: | Roy Scheidsbach, David H. Parker, Chandan Kumar Bishwakarma, Yulia N. Kalugina, François Lique, George van Oevelen |
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| Přispěvatelé: | Laboratoire Ondes et Milieux Complexes (LOMC), Centre National de la Recherche Scientifique (CNRS)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU) |
| Rok vydání: | 2018 |
| Předmět: |
[PHYS]Physics [physics]
010304 chemical physics Molecular cloud General Physics and Astronomy Inelastic scattering 01 natural sciences 7. Clean energy Spectral line Crossed molecular beam Interstellar medium 13. Climate action Ionization 0103 physical sciences Molecular and Laser Physics Physical and Theoretical Chemistry Atomic physics 010303 astronomy & astrophysics Collisional excitation ComputingMilieux_MISCELLANEOUS Excitation |
| Zdroj: | Journal of Chemical Physics, 149, 1-6 Journal of Chemical Physics, 149, 12, pp. 1-6 Journal of Chemical Physics Journal of Chemical Physics, American Institute of Physics, 2018, 149 (12), pp.121101. ⟨10.1063/1.5051610⟩ |
| ISSN: | 1089-7690 0021-9606 |
| DOI: | 10.1063/1.5051610 |
| Popis: | Molecular oxygen (O2) is predicted to be a major reservoir of elemental oxygen in dense interstellar molecular clouds. However, the abundance of O2 derived from astronomical observations is much lower than expected. Solving the discrepancies between models and observations requires a review of the chemistry and collisional excitation of O2 in space. In particular, O2-H2 collisions are crucial to derive O2 abundance in space from the interstellar spectra. A crossed molecular beam experiment to probe the rotational excitation of O2 due to H2 collisions at energies of 650 cm-1 is reported. Velocity map imaging was combined with state-selective detection of O2( X 3 Σ g - ) by (2 + 1) resonance-enhanced multiphoton ionization. The obtained raw O 2 + images were corrected from density to flux and the differential cross sections (DCSs) were then extracted. Exact quantum mechanical calculations were also performed. Very good agreement between experimental and theoretical DCSs was found. The agreement demonstrates our ability to determine inelastic processes between O2 molecules and H2 both theoretically and experimentally and that the excitation of O2 in the interstellar medium can be correctly modeled. Consequences on the astrophysical modeling are briefly evaluated. |
| Databáze: | OpenAIRE |
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