On HC<sub>n</sub>S (n ≥ 2) Radicals in the ISM

J. Cernicharo, C. Cabezas, M. Agúndez, B. Tercero, J. R. Pardo, N. Marcelino, J. D. Gallego, F. Tercero, J. A. López-Pérez, and P. de Vicente
reported on
TMC-1, the starless core sulfur factory: Discovery of NCS, HCCS, H<sub>2</sub>CCS, H<sub>2</sub>CCCS, and C<sub>4</sub>S and detection of C<sub>5</sub>S
Astron. Astrophys. 648, Art. No. L3 (2021).
The ethynylsulfanyl radical, HCCS, was identified through 2 1H hyperfine components of the 2Π3/2 J = 7/2 − 5/2 transition near 41.1 GHz 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. The column density is slightly lower than that of H2CCS and about a factor of ten lower than that of HCS.

R. Fuentetaja, M. Agúndez, C. Cabezas, B. Tercero, N. Marcelino, J. R. Pardo, P. de Vicente, and J. Cernicharo
reported on
Discovery of Two New Interstellar Molecules with QUIJOTE: HCCCHCCC and HCCCCS
Astron. Astrophys. 667, Art. No. L4 (2022).
Butatrienethionyl was detected through six consecutive transitions with 19/2 ≤ J“ ≤ 29/2 between 31.0 and 50.3 GHz 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. The column densities of HCS and HCCS are about factors of 58 and 7.2, respectively, higher than those of HC4S.

J. Cernicharo, C. Cabezas, M. Agúndez, R. Fuentetaja, B. Tercero, N. Marcelino, and P. de Vicente
announced
More sulphur in TMC-1: Discovery of the NC<sub>3</sub>S and HC<sub>3</sub>S radicals with the QUIJOTE line survey
Astron. Astrophys. 688, Art. No. L13 (2024).
Propadienethionyl, HC3S, was detected through three consecutive transitions with 13/2 ≤ J' ≤ 17/2 between 34.8 and 45.6 GHz 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. The lines displayed well-resolved Λ-doubling and (reasonably) resolved 1H hyperfine structure splitting. Some HFS compoents are (essentially) unblended, several slightly or severely. The authors state abundance ratios HCS/HCCS of ~8.1, HCCS/HC3S of ~4.5, and HC3S/HC4S of ~1.6. HC5S was evaluated to be near the present sensitivity limit of the survey.

Contributor(s): H. S. P. Müller; 04, 2021; 11, 2022; 08, 2024