PI: Miwa Goto, University Observatory Munich, firstname.lastname@example.org
Address: Scheinerstr. 1, Munich, Bavaria D-81679, Germany
CoI: Tom Geballe, Gemini Observatory
Title: Searching for H_3^+ isotopomers in the infrared
Abstract: We propose to use Phoenix to detect H_2D^+ in the infrared. In dense clouds the triatomic hydrogen molecular ion is highly fractionated with deuterium, because of the exothermic ion-neutral reaction of H_3^+ with deuterated molecular hydrogen HD. In the deuteration ladder of H_3^+ \rightarrow H_2D^+ \rightarrow D_2H^+ \rightarrow D_3^+, both ends, H_3^+ and D_3^+, are symmetric top molecules, only observable in the infrared. H_2D^+ has been detected at sub-mm wavelengths via its rotational transitions. The infrared absorption spectra of H_2D^+ and D_2H^+ will permit a straightforward quantitative comparison of the column density with H_3^+.
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