Volume 485, Number 3, July III 2008
|Page(s)||L33 - L36|
|Published online||04 June 2008|
Letter to the Editor
Tentative detection of phosphine in IRC +10216*
Departamento de Astrofísica Molecular e Infrarroja, Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid, Spain e-mail: [marce;cerni;pardo]@damir.iem.csic.es
2 Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 St. Martin d'Hères, and LERMA/École Normale Supérieure, 24 rue Lhomond, 75231 Paris, France e-mail: email@example.com
3 California Institute of Technology, Downs Laboratory of Physics 320-47, Pasadena, CA 91125, USA e-mail: firstname.lastname@example.org
Accepted: 27 May 2008
Aims. The JK = 10-00 rotational transition of phosphine (PH3) at 267 GHz has been tentatively identified with a ~ 40 mK spectral line observed with the IRAM 30-m telescope in the C-star envelope IRC +10216.
Methods. A radiative transfer model was used to fit the observed line profile.
Results. The derived PH3 abundance relative to H2 is 6 10-9, although it may have a large uncertainty due to the lack of knowledge about the spatial distribution of this species. If our identification is correct, it implies that PH3 has a similar abundance to what is reported for HCP in this source and that these two molecules (HCP and PH3) together take up about 5% of phosphorus in IRC +10216. The abundance of PH3, like that of other hydrides in this source, is not well explained by conventional gas-phase LTE and non-LTE chemical models, and may imply formation on grain surfaces.
Key words: stars: individual: IRC +10216 / stars: carbon / radio lines: stars / astrochemistry / line: identification / stars: AGB and post-AGB
Based on observations carried out with the IRAM 30-m telescope and the Caltech Submillimeter Observatory (CSO). IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). The CSO is operated by the California Institute of Technology under funding from the National Science Foundation, Grant No. AST-0540882.
© ESO, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.