Issue |
A&A
Volume 688, August 2024
|
|
---|---|---|
Article Number | L13 | |
Number of page(s) | 5 | |
Section | Letters to the Editor | |
DOI | https://doi.org/10.1051/0004-6361/202451256 | |
Published online | 07 August 2024 |
Letter to the Editor
More sulphur in TMC-1: Discovery of the NC3S and HC3S radicals with the QUIJOTE line survey⋆
1
Dept. de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
e-mail: jose.cernicharo@csic.es
2
Observatorio Astronómico Nacional (OAN, IGN), C/ Alfonso XII, 3, 28014 Madrid, Spain
3
Observatorio de Yebes (IGN), Cerro de la Palera s/n, 19141 Yebes, Guadalajara, Spain
Received:
25
June
2024
Accepted:
5
July
2024
We present the detection of the free radicals NC3S and HC3S towards TMC-1 with the QUIJOTE line survey. The derived column densities are (1.4 ± 0.2)×1011 for NC3S and (1.5 ± 0.2)×1011 for HC3S. We searched for NCCS, but only three transitions are within the domain of our QUIJOTE line survey and the observed lines are marginally detected at the 3σ level, providing an upper limit to its column density of ≤6 × 1010 cm−2. We also unsuccessfully searched for longer species of the NCnS (n ≥ 4) and HCnS (n ≥ 5) families in our TMC-1 data. A chemical model based on a reduced set of reactions involving HC3S and NC3S predicts abundances that are 10–100 times below the observed values. These calculations indicate that the most efficient reactions of formation of HC3S and NC3S in the model are S + C3H2 and N + HC3S, respectively, while both radicals are very efficiently destroyed through reactions with neutral atoms.
Key words: astrochemistry / line: identification / molecular data / ISM: molecules / ISM: individual objects: TMC-1
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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