Awad, Z;
Viti, S;
Williams, DA;
(2016)
On the Chemistry of Hydrides of N Atoms and O+ Ions.
Astrophysical Journal
, 826
(2)
, Article 207. 10.3847/0004-637X/826/2/207.
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Abstract
Previous work by various authors has suggested that the detection by Herschel/HIFI of nitrogen hydrides along the low-density lines of sight toward G10.6-0.4 (W31C) cannot be accounted for by gas-phase chemical models. In this paper we investigate the role of surface reactions on dust grains in diffuse regions, and we find that formation of the hydrides by surface reactions on dust grains with efficiency comparable to that for H2 formation reconciles models with observations of nitrogen hydrides. However, similar surface reactions do not contribute significantly to the hydrides of O+ ions detected by Herschel/HIFI that are present along many sight lines in the Galaxy. The O+ hydrides can be accounted for by conventional gas-phase chemistry either in diffuse clouds of very low density with normal cosmic-ray fluxes or in somewhat denser diffuse clouds with high cosmic-ray fluxes. Hydride chemistry in dense dark clouds appears to be dominated by gas-phase ion–molecule reactions.
| Type: | Article |
|---|---|
| Title: | On the Chemistry of Hydrides of N Atoms and O+ Ions |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/0004-637X/826/2/207 |
| Publisher version: | http://doi.org/10.3847/0004-637X/826/2/207 |
| Language: | English |
| Additional information: | Copyright © 2016. The American Astronomical Society. All rights reserved. |
| Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, astrochemistry, dust, extinction, ISM: abundances, ISM: clouds, ISM: molecules, SOLID N-2 MATRIX, TO-PARA RATIO, NITROGEN HYDRIDES, UMIST DATABASE, AMMONIA FORMATION, DARK CLOUDS, HERSCHEL/HIFI OBSERVATIONS, INTERSTELLAR CHEMISTRY, MOLECULAR-HYDROGEN, LOW-TEMPERATURES |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1521639 |
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