J. Cernicharo, C. Cabezas, Y. Endo, M. Agúndez, B. Tercero, J. R. Pardo, N. Marcelino, and P. de Vicente
report on
The Sulphur Saga in TMC-1: Discovery of HCSCN and HCSCCH
Astron. Astrophys. 650, Art. No. L14 (2021).
Cyanothioformaldehyde, aka thioformyl cyanide, was identified through 10 unblended or only slightly blended a-type transitions with 4 ≤ J ≤ 8 and K_a ≤ 1 in the course of a molecular line survey of the prototypical cold dark molecular cloud TMC-1 carried out with the Yebes 40 m radio telescope between 30.1 and 50.4 GHz. Also observed were 9 much weaker b-type transitions with 1 ≤ J ≤ 9 and K_a ≤ 1; some of these were blended, and several were affected by low signal-to-noise ratios. A value of T_rot = 5.0 ± 0.5 K was derived. The column density of HC(S)CN is unusually high compared to related molecules. It is about a factor of 4 higher than that of the isovalent HC(O)CN, whereas the one of HC₂CHS is about a factor of 5 lower than that of HC₂CHO, similar to the corresponding factor of 10 between thioformaldehyde and formaldehyde.

Contributor(s): H. S. P. Müller; 06, 2021