Viti, S;
Fontani, F;
Jiménez-Serra, I;
Holdship, J;
(2019)
Nitrogen fractionation in external galaxies.
Monthly Notices of the Royal Astronomical Society
, 486
(4)
pp. 4805-4812.
10.1093/mnras/stz1172.
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Abstract
In star-forming regions in our own Galaxy, the 14N/15N ratio is found to vary from ~100 in meteorites, comets, and protoplanetary discs up to ~1000 in pre-stellar and star-forming cores, while in external galaxies the very few single-dish large-scale measurements of this ratio lead to values of 100-450. The extent of the contribution of isotopic fractionation to these variations is, to date, unknown. In this paper, we present a theoretical chemical study of nitrogen fractionation in external galaxies in order to determine the physical conditions that may lead to a spread of the 14N/15N ratio from the solar value of ~440 and hence evaluate the contribution of chemical reactions in the interstellar medium (ISM) to nitrogen fractionation. We find that the main cause of ISM enrichment of nitrogen fractionation is high gas densities, aided by high fluxes of cosmic rays.
| Type: | Article |
|---|---|
| Title: | Nitrogen fractionation in external galaxies |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stz1172 |
| Publisher version: | https://doi.org/10.1093/mnras/stz1172 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | ISM: abundances, ISM: molecules, galaxies: ISM |
| 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/10077717 |
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