Dynamic model atmospheres of AGB stars IV. A comparison of synthetic carbon star spectra with observations

Author(s)
Rita Loidl, Susanne Höfner, Uffe Grae Jorgensen, Josef Hron
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, C2, CS, HCN, C2H2 and C3 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 œm of TX Psc, WZ Cas, V460Cyg, 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 5œm. At longer wavelengths our models showing mass loss offer a first self-consistent qualitative explanation of why a strong feature around 14 œm, which is predicted by all hydrostatic models as well as dynamical models showing no mass loss, is missing in observed AGB carbon star spectra.

Organisation(s)
Department of Astrophysics
External organisation(s)
Uppsala University, University of Copenhagen
Journal
Astronomy & Astrophysics
Volume
422
Pages
289-306
No. of pages
18
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361:20035860
Publication date
2004
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/a4f9eca8-c6e3-4834-ab9d-f3eba1fd8331