Detection of HCS+ in the ISM

The thioformyl cation, HCS+, has been observed in the ISM prior to the laboratory by
P. Thaddeus, M. Guélin, and R. A. Linke,
Three New 'Nonterrestrial' Molecules
Astrophys. J. 246, L41–L45 (1981).
The J = 2 – 1 transition near 85.3 GHz was detected toward the hot-core sources Orion KL, Sgr B2(OH), and DR 21 as well as toward the dense cold cloud TMC-1. In addition, the 3 – 2, 5 – 4, and 6 – 5 transitions were also detected in Orion KL.

The molecular cation was also detected in several translucent molecular clouds by
B. E. Turner,
The Physics and Chemistry of Small Translucent Molecular Clouds. VI. Organo-Sulfur Species
Astrophys. J. 416, 246–264 (1996)

The 7 – 6, and 8 – 7 transitions were detected in a PDR by
S. Leurini, R. Rolffs, S. Thorwirth, B. Parise, P. Schilke, C. Comito, F. Wyrowski, R. Güsten, P. Bergman, K. M. Menten, and L.-Ċ. Nyman,
APEX 1 mm Line Survey of the Orion Bar
Astron. Astrophys. 454, L47–L50 (2006)

A. Fuente, J. Cernicharo, E. Roueff, M. Gerin, J. Pety, N. Marcelino, R. Bachiller, B. Lefloch, O. Roncero, and A. Aguado,
studied the
Ionization Fraction and the Enhanced Sulfur Chemistry in Barnard 1
Astron. Astrophys. 593, Art. No. A94 (2016).
They used the IRAM 30 m telescope for a molecular line survey at 3, 2, and 1.3 mm. The J = 3 – 2 transition of DCS+ at 108.108 GHz was detected in emission. An LVG analysis suggests a D/H ratio of almost 0.1 in the region in which the DCS+ emission was detected.

A. Potapov, Á. Sánchez-Monge, P. Schilke, U. U. Graf, T. Möller, and S. Schlemmer
reported almost at the same time on the detection of the same transition in their search for
The CO–H2 van der Waals complex and complex organic molecules in cold molecular clouds: A TMC-1C survey
Astron. Astrophys. 594, Art. No. A117 (2016).
The IRAM 30 m telescope was used once more.

Contributor(s): H. S. P. Müller; 12, 2003; 09, 2011; 11, 2016