[SEMINARI] Resolving the atmospheres of AGBs with IR-interferometry, Ivan Martí

[Enric Marco]

Resolving the atmospheres of AGBs with IR-interferometry

Dr. Ivan Martí-Vidal

Max Planck Institut für Radioastronomie, Bonn, Germany

Seminari del departament d'Astronomia i Astrofísica

Dijous 09 setembre 2010

12:00

Resum

Most of the stardust in the interstellar medium (ISM) comes from the 
dense stellar winds of Assymptotic Giant Branch (AGB) stars. The 
mechanism of this wind is not well understood yet. I will shortly 
discuss on the existing models of AGB atmospheres and winds and the 
problems of these models to explain the current spectroscopic and 
interferometric (high spatial-resolution) observations. I will finally 
report on new observations of a semi-regular AGB in the near-IR with the 
AMBER detector at the Very Large Telescope Interferometer (VLTI). A 
short technical description of this detector and the 
calibration/reduction procedure will be presented. Our observations 
cannot be explained with the current stellar models unless we use a mass 
much lower than predicted by stellar evolution and/or assume an ad-hoc 
warm molecular outer envelope. This would be the first 
spectro-interferometric evidence of an extended molecular layer around a 
semi-regular AGB star, and would be placed somewhere between the warm 
photosphere and the base of the dust-driven stellar wind.

-- 
/------------------------------------\
 Dr. Enric Marco
 Departament d'Astronomia i Astrofísica
 Facultat de Física
 Universitat de València
 C/  Dr. Moliner, 50
 46100 Burjassot, Spain
 Phone: (34)-96-354-3069
 Fax:(34)-96-354-3084
 enric.marco en uv.es
 http://www.uv.es/marco
 http://www.uv.es/aulaastronomia
 http://www.uv.es/daa
 \--------------------------------------/