Issue |
A&A
Volume 689, September 2024
|
|
---|---|---|
Article Number | A260 | |
Number of page(s) | 8 | |
Section | Interstellar and circumstellar matter | |
DOI | https://doi.org/10.1051/0004-6361/202451518 | |
Published online | 18 September 2024 |
Advancing spectroscopic understanding of HOCS+: Laboratory investigations and astronomical implications
1
Center for Astrochemical Studies, Max-Planck-Institut für Extraterrestrische Physik,
Gießenbachstraße 1,
85748
Garching,
Germany
2
Centro de Astrobiología (CAB), INTA-CSIC,
Carretera de Ajalvir km 4, Torrejón de Ardoz,
28850
Madrid,
Spain
Received:
15
July
2024
Accepted:
5
August
2024
Sulphur-bearing species play crucial roles in interstellar chemistry, yet their precise characterisation remains challenging. Here, we present laboratory experiments aimed at extending the high-resolution spectroscopy of protonated carbonyl sulphide (HOCS+), a recently detected molecular ion in space. Using a frequency-modulated free-space absorption spectrometer, we detected rotational transitions of HOCS+ in an extended negative glow discharge with a mixture of H2 and OCS, extending the high-resolution rotational characterisation of the cation well into the millimetre wave region (200–370 GHz). Comparisons with prior measurements and quantum chemical calculations revealed an overall agreement in the spectroscopic parameters. With the new spectroscopic dataset in hand, we re-investigated the observations of HOCS+ towards G+0.693−0.027, which were initially based solely on Ka = 0 lines contaminated by HNC34S. This re-investigation enabled the detection of weak Ka ≠ 0 transitions, free from HNC34S contamination. Our high-resolution spectroscopic characterisation also provides valuable insights for future millimetre and submillimetre astronomical observations of these species in different interstellar environments. In particular, the new high-resolution catalogue will facilitate the search for this cation in cold dark clouds, where very narrow line widths are typically observed.
Key words: line: identification / molecular data / ISM: abundances / ISM: clouds / ISM: molecules
© 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.
This article is published in open access under the Subscribe to Open model.
Open Access funding provided by Max Planck Society.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.