Ground-based searches for interstellar H_(2)D^+
Abstract
We present ground-based searches for the 1_(10) - 1_(11) line of interstellar H_(2)D^(+) at 372 GHz which are more sensitive than those obtained from the Kuiper Airborne Observatory by factors of 3-4 for extended sources and by more than two orders of magnitude for compact sources. The line was not detected in a variety of interstellar clouds, including NGC 2264 toward which a possible detection had been suggested previously. The inferred H_(2)D^(+) abundance limits of 10^(-10) - 10^(-11) are still consistent with, but approach the abundances predicted by chemical models. Simultaneous observations of the DCO^(+) 3-2 and N_(2)H^(+) 4-3 lines have been used to place additional limits on the H_(3)^(+) abundance, and suggest 10^(-11) < x(H_(3)^(+))< 10^(-9). The N_(2)H^(+) data also indicate that for NGC 2264, but perhaps not for the other sources, gas-phase N_2 contains a substantial fraction of the available nitrogen in the cloud.
Additional Information
© 1992 EDP Sciences. Received April 24, accepted May 15, 1992. The authors are grateful to the CSO staff for their support, and to J. Black and J. Rawlings for discussions. Financial backing came from NSF grant AST 90-15755 and the Netherlands Organization for Scientific Research, NWO.Attached Files
Published - vanDishoeck_AstAstro1992pL13.pdf
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Additional details
- Eprint ID
- 34215
- Resolver ID
- CaltechAUTHORS:20120919-115851027
- AST 90-15755
- NSF
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)
- Created
-
2012-09-19Created from EPrint's datestamp field
- Updated
-
2020-05-12Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences