Issue A&A Volume 505, Number 3, October III 2009 Page(s) 1233 - 1235 Section Stellar atmospheres DOI 10.1051/0004-6361/200911753 Published online 27 August 2009

A&A 505, 1233-1235 (2009)
DOI: 10.1051/0004-6361/200911753

Research Note

Modelling convection in A star atmospheres

Bisectors and lineshapes of HD 108642

Ch. Stütz

University of Vienna, Universitätsstrasse 7, 1010 Vienna, Austria
    e-mail: christian.stuetz@univie.ac.at

Received 30 January 2009 / Accepted 3 July 2009

Abstract
Context. We present a code, VeDyn, for modelling envelopes and atmospheres of A to F stars focusing on accurate treatment of convective processes.
Aims. VeDyn implements a highly sophisticated non-local convection model but is fast and can be used in practical astrophysical applications.
Methods. We developed the HME envelope solver for this convection model to consistently model the envelope together with the stellar atmosphere. The synthesis code SynthV was extended to account for the resulting velocity structure. Finally, we tested our approach on atomic line bisectors.
Results. It is shown that our synthetic line bisectors of HD 108642 bend towards the blue and are of a magnitude comparable to the observed ones.
Conclusions. Even though this approach of modelling convection requires the solution of a coupled system of nonlinear differential equations, it is fast enough to be applicable to many of the investigation techniques relying on model atmospheres.

Key words: convection -- stars: atmospheres -- line: profiles -- turbulence -- stars: individual: HD 108642

© ESO 2009

What is OpenURL?