Herschel/HIFI discovery of interstellar chloronium (H2Cl+) ***
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چکیده
We report the first detection of chloronium, H2Cl, in the interstellar medium, using the HIFI instrument aboard the Herschel Space Observatory. The 212−101 lines of ortho-H35 2 Cl and ortho-H37 2 Cl are detected in absorption towards NGC 6334I, and the 111−000 transition of para-H35 2 Cl is detected in absorption towards NGC 6334I and Sgr B2(S). The H2Cl column densities are compared to those of the chemically-related species HCl. The derived HCl/H2Cl column density ratios, ∼1–10, are within the range predicted by models of diffuse and dense photon dominated regions (PDRs). However, the observed H2Cl column densities, in excess of 1013 cm−2, are significantly higher than the model predictions. Our observations demonstrate the outstanding spectroscopic capabilities of HIFI for detecting new interstellar molecules and providing key constraints for astrochemical models.
منابع مشابه
Chlorine Chemistry in the Interstellar Medium
Prior to the launch of Herschel, HCl was the only chlorine-containing molecule detected in the interstellar medium (ISM). However, chemical models have identified chloronium, H2Cl, as a relatively abundant species that is potentially detectable. H2Cl was predicted to be most abundant in the environments where the ultraviolet radiation is strong: in diffuse clouds, or near the surfaces of dense ...
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تاریخ انتشار 2010