EDP Sciences
Free access
Volume 439, Number 3, September I 2005
Page(s) 1137 - 1148
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20042338

A&A 439, 1137-1148 (2005)
DOI: 10.1051/0004-6361:20042338

PHOENIX model chromospheres of mid- to late-type M dwarfs

B. Fuhrmeister, J. H. M. M. Schmitt and P. H. Hauschildt

Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
    e-mail: bfuhrmeister@hs.uni-hamburg.de

(Received 9 November 2004 / Accepted 28 April 2005)

We present semi-empirical model chromospheres computed with the atmosphere code PHOENIX. The models are designed to fit the observed spectra of five mid- to late-type M dwarfs. Next to hydrogen lines from the Balmer series we used various metal lines, e.g. from Fe I, for the comparison between data and models. Our computations show that an NLTE treatment of C, N, O impacts on the hydrogen line formation, while NLTE treatment of less abundant metals such as nickel influences the lines of the considered species itself. For our coolest models we investigated also the influence of dust on the chromospheres and found that dust increases the emission line flux.

Moreover we present an (electronically published) emission line list for the spectral range of 3100 to 3900 and 4700 to 6800 Å for a set of 21 M dwarfs and brown dwarfs. The line list includes the detection of the Na I D lines in emission for a L3 dwarf.

Key words: stars: activity -- stars: late-type -- stars: chromospheres

SIMBAD Objects
Tables at the CDS

© ESO 2005

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.