The J = 5/2 3/2 transition of the
lower energy fine structure component 2Π3/2
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.