EDP Sciences
Free access
Volume 384, Number 2, March III 2002
Page(s) 568 - 584
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20011814

A&A 384, 568-584 (2002)
DOI: 10.1051/0004-6361:20011814

Nanodiamonds around HD 97048 and Elias 1

C. Van Kerckhoven1, A. G. G. M Tielens2, 3 and C. Waelkens1

1  Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200B, 3001 Heverlee, Belgium
2  Kapteyn Astronomical Institute, PO Box 800, 9700 AV Groningen, The Netherlands
3  SRON, PO Box 800, 9700 AV Groningen, The Netherlands

(Received 5 June 2001 / Accepted 11 December 2001)

We present an analysis of ISO-SWS observations of the Herbig Ae/Be stars HD 97048 and Elias 1. Besides the well-known family of IR emission bands at 3.3, 6.2, "7.7", 8.6 and 11.2  $\mu$m these objects show strong, peculiar emission features at 3.43 and 3.53  $\mu$m. The latter two features show pronounced substructure which is very similar in the two sources. Comparison of the spectra of HD 97048 and Elias 1 with laboratory spectra of H-terminated diamond surfaces show excellent and very convincing agreement in peak position and spectral detail (Guillois et al. 1999). The position of the 3.53  $\mu$m band indicates a temperature of ~1000 K. An analysis of the radiative energy budget makes us conclude that the diamond carrier of the 3.53  $\mu$m feature has typical sizes of 1-10 nm for HD 97048. A fit of the 3.53  $\mu$m feature with a theoretical, calculated profile indicates that the emitting diamonds in HD 97048 see a FUV flux of 5.8 $\times$ 10 -3 [ W/cm 2] . The derived diamond mass, 1.5 $\times$ 10 -10  $M_{\odot}$, is only a tiny fraction of the total circumstellar dust mass and corresponds to only about 1 parts per billion relative to hydrogen. We discuss the origin of the diamond around these Herbig Ae/Be stars and conclude that most likely they are formed in situ. The implications for the nanodiamonds discovered in meteorites are also discussed.

Key words: circumstellar matter -- infrared: ISM: lines and bands -- ISM: general -- ISM: molecules, dust -- ISM: individual: HD 97048, Elias 1

Offprint request: C. Van Kerckhoven, caroline@ster.kuleuven.ac.be

SIMBAD Objects

© ESO 2002

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.