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arXiv · 1408.6055

Evolved stars with complex atmospheres - the high spectral resolution, mid-IR view

N. Ryde·J. Lambert·M. J. Richter·E. Josselin·G. M. Harper·K. Eriksson·A. Boogert·C. DeWitt·T. Encrenaz·T. Greathouse·D. Jaffe·K. Kulas·M. McKelvey·J. Najita·W. Vacca
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Abstract

The physical structures of the outer atmospheres of red giants are not known. They are certainly complex and a range of recent observations are showing that we need to embrace to non-classical atmosphere models to interpret these regions. This region's properties is of importance, not the least, for the understanding of the mass-loss mechanism for these stars, which is not still understood. Here, we present observational constraints of the outer regions of red giants, based on mid-IR, high spectral resolution spectra. We also discuss possible non-LTE effects and highlight a new non-LTE code that will be used to analyse the spectra of these atmospheric layers. We conclude by mentioning our new SOFIA/EXES observations of red giants at 6 microns, where the vibration-rotation lines of water vapour can be detected and spectrally resolved for the first time.

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N. Ryde, J. Lambert, M. J. Richter, E. Josselin, G. M. Harper, K. Eriksson, A. Boogert, C. DeWitt, T. Encrenaz, T. Greathouse, D. Jaffe, K. Kulas, M. McKelvey, J. Najita, W. Vacca. 2014-08-26. Evolved stars with complex atmospheres - the high spectral resolution, mid-IR view. https://arxiv.org/abs/1408.6055

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