2019/10/29 by V. V. Ilyushin, O. Zakharenko, Olena Zakharenko +15 · 8 citations
Chemistry · Earth and Planetary Sciences · Physics and Astronomy · #Analytical Chemistry (journal) #Astrochemistry #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Atmospheric Ozone and Climate #Atomic physics #Chemistry #Excited state #Galactic Center #Galaxy #Interstellar medium #Isotopologue #Millimeter #Molecular Spectroscopy and Structure #Molecule #Physics #Spectral line #astro-ph.GA #astro-ph.IM #astro-ph.SR #physics.atm-clus #physics.chem-ph
paper · pdf · open access · doi:10.1139/cjp-2019-0421
published in Canadian Journal of Physics 98(6), 530-537 (NRC Research Press) · 20 pages (with figures and tables); Can. J. Phys. (https://www.nrcresearchpress.com/journal/cjp), accepted
openalex created_date 2019/10/10 · openalex publication_date 2019/10/29 · arxiv created 2019/11/20 · arxiv updated 2020/06/09 · openalex updated_date 2026/08/05
Methyl mercaptan (CH 3 SH) is a known interstellar molecule with abundances high enough that the detection of some of its minor isotopologues is promising. The present study aims to provide accurate spectroscopic parameters for the 13 CH 3 SH isotopologue to facilitate its identification in the interstellar medium at millimetre and submillimetre wavelengths. Through careful analysis of recent CH 3 SH spectra from 49–510 GHz and 1.1–1.5 THz recorded at natural isotopic composition, extensive assignments were possible not only for the ground torsional state of 13 CH 3 SH, but also in the first and second excited states. The torsion–rotation spectrum displays complex structure due to the large-amplitude internal rotation of the 13 CH 3 group, similar to the main and other minor isotopic species of methyl mercaptan. The assigned transition frequencies have been fitted to within experimental error with a 52-parameter model employing the RAM36 programme. With predictions based on this fit, 13 CH 3 SH was searched for in spectra from the Atacama Large Millimetre/sub-millimetre Array (ALMA) towards the Galactic centre source Sgr B2(N2). Several transitions were expected to be observable, but all of them turned out to be severely blended with emission from other species, which prevents us from identifying 13 CH 3 SH in this source.