Gomez-Ruiz, AI;
Codella, C;
Viti, S;
Jimenez-Serra, I;
Navarra, G;
Bachiller, R;
Caselli, P;
... Nisini, B; + view all
(2016)
Diagnosing shock temperature with NH3 and H2O profiles.
Monthly Notices Of The Royal Astronomical Society
, 462
(2)
pp. 2203-2217.
10.1093/mnras/stw1811.
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Abstract
In a previous study of the L1157 B1 shocked cavity, a comparison between NH3(10–00) and H2O(110–101) transitions showed a striking difference in the profiles, with H2O emitting at definitely higher velocities. This behaviour was explained as a result of the high-temperature gas-phase chemistry occurring in the post-shock gas in the B1 cavity of this outflow. If the differences in behaviour between ammonia and water are indeed a consequence of the high gas temperatures reached during the passage of a shock, then one should find such differences to be ubiquitous among chemically rich outflows. In order to determine whether the difference in profiles observed between NH3 and H2O is unique to L1157 or a common characteristic of chemically rich outflows, we have performed Herschel-HIFI observations of the NH3(10–00) line at 572.5 GHz in a sample of eight bright low-mass outflow spots already observed in the H2O(110–101) line within the Water In Star-forming regions with Herschel Key Programme. We detected the ammonia emission at high velocities at most of the outflows positions. In all cases, the water emission reaches higher velocities than NH3, proving that this behaviour is not exclusive of the L1157-B1 position. Comparisons with a gas–grain chemical and shock model confirms, for this larger sample, that the behaviour of ammonia is determined principally by the temperature of the gas.
| Type: | Article |
|---|---|
| Title: | Diagnosing shock temperature with NH3 and H2O profiles |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stw1811 |
| Publisher version: | http://dx.doi.org/10.1093/mnras/stw1811 |
| Language: | English |
| Additional information: | © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society |
| Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, Molecular Data, Stars: Formation, Ism: Molecules, Radio Lines: Ism, Submillimetre: Ism, Star-Forming Regions, Protostellar Outflows, Bipolar Outflows, Herschel-Pacs, Water, Evolution, L1157, Program, Protostars, Chemistry |
| 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-pp.ucl.ac.uk/id/eprint/1530266 |
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