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arXiv · 1304.4111

NLTE water lines in Betelgeuse-like atmospheres

Julien Lambert·Eric Josselin·Nils Ryde·Alexandre Faure
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Abstract

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.

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Julien Lambert, Eric Josselin, Nils Ryde, Alexandre Faure. 2013-04-15. NLTE water lines in Betelgeuse-like atmospheres. https://doi.org/10.1051/eas%2F1360012

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