EDP Sciences
Free access
Volume 485, Number 3, July III 2008
Page(s) L33 - L36
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:200810193
Published online 04 June 2008

A&A 485, L33-L36 (2008)
DOI: 10.1051/0004-6361:200810193


Tentative detection of phosphine in IRC +10216

M. Agúndez1, J. Cernicharo1, J. R. Pardo1, M. Guélin2, and T. G. Phillips3

1  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: guelin@iram.fr
3  California Institute of Technology, Downs Laboratory of Physics 320-47, Pasadena, CA 91125, USA
    e-mail: tgp@submm.caltech.edu

Received 14 May 2008 / Accepted 27 May 2008

Aims. The $J_{\rm K}$ = 10-00 rotational transition of phosphine (PH3) at 267 GHz has been tentatively identified with a $T_{\rm
MB}$ ~ 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 $\times$ 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

© ESO 2008

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access.

An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account.
    In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.