EDP Sciences
Free access
Volume 480, Number 1, March II 2008
Page(s) 133 - 148
Section Interstellar and circumstellar matter
DOI http://dx.doi.org/10.1051/0004-6361:20065282

A&A 480, 133-148 (2008)
DOI: 10.1051/0004-6361:20065282

A search for diffuse bands in the circumstellar envelopes of post-AGB stars

R. Luna1, N. L. J. Cox2, M. A. Satorre1, D. A. García Hernández3, O. Suárez4, and P. García Lario2

1  Laboratorio de Astrofísica Experimental, Escuela Politécnica Superior de Alcoy, Universidad Politécnica de Valencia, Plaza de Ferrándiz y Carbonell, 03801 Alcoy, Alicante, Spain
    e-mail: ralunam@fis.upv.es
2  Herschel Science Centre, Research and Scientific Support Department of ESA, European Space Astronomy Centre, PO Box 78, 28691 Villanueva de la Cañada, Madrid, Spain
3  W. J. McDonald Observatory. The University of Texas at Austin. 1 University Station, C1400. Austin, TX 78712-0259, USA
4  LUAN, Université de Nice Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 2, France

(Received 27 March 2006 / Accepted 6 November 2007)

In this work we present the results of a systematic search for diffuse bands (DBs, hereafter) in the circumstellar envelopes of a carefully selected sample of post-AGB stars. We concentrated on analyzing 9 of the DBs most commonly found in the interstellar medium. The strength of these features is determined using high-resolution optical spectroscopy, and the results obtained are compared with literature data on field stars affected only by interstellar reddening. Based on the weak features observed in the subsample of post-AGB stars dominated by circumstellar reddening, we conclude that the carrier(s) of these DBs must not be present in the circumstellar environment of these sources, or at least not under the excitation conditions in which DBs are formed. This conclusion is applicable to all the post-AGB stars studied, irrespective of the dominant chemistry or the spectral type of the star considered. A detailed radial velocity analysis of the features observed in individual sources confirms this result, as the Doppler shifts measured are found to be consistent with an interstellar origin.

Key words: stars: AGB and post-AGB -- ISM: dust, extinction

© 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.