Cool Stars 14 - Submitted Abstract # 148
This version created on 05 October 2006

Red supergiant convection and atmosphere


Andrea Chiavassa, GRAAL, University of Montpellier II, France
Bertrand Plez, GRAAL, University of Montpellier II, France
Eric Josselin, GRAAL, University of Montpellier II, France
Bernd Freytag, Uppsala University, Sweden and CRAL-ENS, France
Nils Ryde, Uppsala University, Sweden

We developed a 3D pure LTE radiative transfer code, in order to
compute emerging spectra and monochromatic maps from
radiative-hydrodynamic simulations of red supergiant stars (RSGs),
carried out with CO5BOLD (Freytag et al.  2002, Astron.  Nachr.  323,
213).  In this poster we first show that 3D calculations of 12 μm
H2O lines are in much better agreement with high-resolution infrared
spectroscopic observations (Ryde et al.  2006, ApJ 637, 1040) than any
previous calculation, bringing further evidence that MOLspheres may
not be required to explain H2O lines.  We then present maps and
visibilities computed in the IR and discuss prospects to detect and
measure the granulation pattern of RSGs with interferometers such as
the VLTI/AMBER.  Finally, we compare detailed line profile
calculations with highresolution optical spectroscopic observations by
Josselin and Plez (this conference).  We discuss the (lack of)
agreement between models and observations and propose improvements of
the simulations.

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