A. Fuente, J. R. Goicoechea, J. Pety, R. Le Gal, R. Martín-Doménech, P. Gratier,
V. Guzmán, E. Roueff, J. C. Loison, G. M. Muñoz Caro, V. Wakelam, M. Gerin,
P. Riviere-Marichalar, and T. Vidal,
reported on the
First Detection of Interstellar S2H,
Astrophys. J. 851 L49 (2017).
The 60,6 50,5 and 70,7 60,6 transitions near 94.6 and 110.4 GHz were detected with the IRAM 30 m telescope in emission toward the Horsehead photodissociation region. The large fine structure splitting was resolved, the very small HFS splitting was not resolved. The radical occurs widespread in this source, both in the interface region (HCO peak) and in the denser and colder region (DCO+ peak). Its column density is only a factor of about four to six lower in this source than that of H2S.