The J = 5/2 – 3/2 transition of the lower energy fine structure component ²Π_3/2 of chloroniumyl has been detected in absorption in the diffuse medium along the sight-lines to the submillimeter continuum sources W31C and W49N by
M. De Luca, H. Gupta, D. Neufeld, M. Gerin, D. Teyssier, B. J. Drouin, J. C. Pearson, D. C. Lis, R. Monje, T. G. Phillips, J. R. Goicoechea, B. Godard, E. Falgarone, A. Coutens, and T. A. Bell,
//Herschel///HIFI Discovery of HCl⁺ in the Interstellar Medium
Astrophys. J. 751, (2012), Art. No. L37.
Two structured features, caused by the ³⁵Cl and ³⁷Cl isotopologs, were observed near 1444 and 1442 GHz. The intricate structure of the features was caused by various clouds along the sight-line, Λ-doubling, and Cl hyperfine structure. The inferred column densities are very similar to those of H₂Cl⁺ and HCl in these sources.

Contributor(s): H. S. P. Müller; 05, 2012.