BibSonomy
CiteUlike
Connotea
Del.icio.us
Digg
Facebook
A&A 422, 289-306 (2004)
DOI: 10.1051/0004-6361:20035860
Dynamic model atmospheres of AGB stars
IV. A comparison of synthetic carbon star spectra with observations
R. Gautschy-Loidl1, S. Höfner2, 3, U. G. Jørgensen4 and J. Hron51 Froburgstrasse 43, 4052 Basel, Switzerland
2 Dept. of Astronomy and Space Physics, Uppsala University, Box 515, 75120 Uppsala, Sweden
3 NORDITA, Blegdamsvej 17, 2100 Copenhagen, Denmark
4 Niels Bohr Institute, Astronomical Observatory, Juliane Maries Vej 30, 2100 Copenhagen, Denmark
5 Institut für Astronomie der Universität Wien, Türkenschanzstraße 17, 1180 Wien, Austria
(Received 13 December 2003 / Accepted 8 April 2004 )
Abstract
We have calculated synthetic opacity sampling spectra
for carbon-rich Asymptotic Giant Branch (AGB) stars based on
dynamic model atmospheres which couple time-dependent dynamics and
frequency-dependent radiative transfer, as presented in the third
paper of this series. We include the molecules CO, CH, CN, C
2,
CS, HCN, C
2H
2 and C
3 in our calculations, both when
computing the atmospheric structures, and the synthetic spectra. A
comparison of the synthetic spectra with various observed colours
and spectra in the wavelength range between 0.5 and 25
m of
TX Psc, WZ Cas, V460 Cyg, T Lyr and S Cep is presented. We
obtain good agreement between observations gathered at different
phases and synthetic spectra of one single hydrodynamical
model for each star in the wavelength region between 0.5 and 5
m. At longer wavelengths our models showing mass loss offer
a first self-consistent qualitative explanation of why a strong
feature around 14
m, which is predicted by all hydrostatic
models as well as dynamical models showing no mass loss, is
missing in observed AGB carbon star spectra.
Key words: stars: AGB and post-AGB -- stars: atmospheres -- stars: variables: general -- stars: carbon -- hydrodynamics -- radiative transfer
Offprint request: R. Gautschy-Loidl, rita@gautschy.ch
SIMBAD Objects
© ESO 2004