Change search
ReferencesLink to record
Permanent link

Direct link
Show others and affiliations
2012 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 748, no 1, 37- p.Article in journal (Refereed) Published
Abstract [en]

Using the Herschel Space Observatory's Heterodyne Instrument for the Far-Infrared, we have observed parachloronium (H2Cl+) toward six sources in the Galaxy. We detected interstellar chloronium absorption in foreground molecular clouds along the sight lines to the bright submillimeter continuum sources Sgr A (+50 km s(-1) cloud) and W31C. Both the para-(H2Cl+)-Cl-35 and para-(H2Cl+)-Cl-37 isotopologues were detected, through observations of their 1(11)-0(00) transitions at rest frequencies of 485.42 and 484.23 GHz, respectively. For an assumed ortho-to-para ratio (OPR) of 3, the observed optical depths imply that chloronium accounts for similar to 4%-12% of chlorine nuclei in the gas phase. We detected interstellar chloronium emission from two sources in the Orion Molecular Cloud 1: the Orion Bar photodissociation region and the Orion South condensation. For an assumed OPR of 3 for chloronium, the observed emission line fluxes imply total beam-averaged column densities of similar to 2 x 10(13) cm(-2) and similar to 1.2 x 10(13) cm(-2), respectively, for chloronium in these two sources. We obtained upper limits on the para-(H2Cl+)-Cl-35 line strengths toward H-2 Peak 1 in the Orion Molecular cloud and toward the massive young star AFGL 2591. The chloronium abundances inferred in this study are typically at least a factor similar to 10 larger than the predictions of steady-state theoretical models for the chemistry of interstellar molecules containing chlorine. Several explanations for this discrepancy were investigated, but none has proven satisfactory, and thus the large observed abundances of chloronium remain puzzling.

Place, publisher, year, edition, pages
2012. Vol. 748, no 1, 37- p.
Keyword [en]
ISM: molecules, molecular processes, submillimeter: ISM
National Category
Astronomy, Astrophysics and Cosmology
URN: urn:nbn:se:su:diva-76151DOI: 10.1088/0004-637X/748/1/37ISI: 000301347500037OAI: diva2:525886
24Available from: 2012-05-09 Created: 2012-05-09 Last updated: 2012-05-09Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Sandqvist, Aage
By organisation
Department of Astronomy
In the same journal
Astrophysical Journal
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 27 hits
ReferencesLink to record
Permanent link

Direct link