EAS Publications Series
Volume 60, 2013Betelgeuse Workshop 2012 The Physics of Red Supergiants: Recent Advances and Open Questions
|Page(s)||111 - 119|
|Section||Atmospheric Structure and Dynamics|
|Published online||23 May 2013|
P. Kervella, T. Le Bertre and G. Perrin (eds)
EAS Publications Series, 60 (2013) 111-119
NLTE water lines in Betelgeuse-like atmospheres
1 LUPM, UMR 5299, CNRS &
Université Montpellier II, Place Eugène Bataillon, 34095
Montpellier Cedex 05,
2 Lund Observatory, Box 43, 22100 Lund, Sweden
3 IPAG, UMR 5274, CNRS & UJF-Grenoble, 38041 Grenoble, France
The interpretation of water lines in red supergiant stellar atmospheres has been much debated over the past decade. The introduction of the so-called MOLspheres to account for near-infrared “extra” absorption has been controversial. We propose that non-LTE effects should be taken into account before considering any extra-photospheric contribution.
After a brief introduction on the radiative transfer treatment and the inadequacy of classical treatments in the case of large-scale systems such as molecules, we present a new code, based on preconditioned Krylov subspace methods. Preliminary results suggest that NLTE effects lead to deeper water bands, as well as extra cooling.
© EAS, EDP Sciences 2013