Studies of circumstellar shells in AGB stars by multifrequency (sub)mm-VLBI observations of maser emission

Abstract : VLBI observations of maser emission are a basic tool to study the circumstellar envelopes (CSEs) around evolved stars, mainly around AGB and post-AGB stars. The maser lines of water and silicon monoxide are particularly intense. They provide us with high spatial resolution data on the very inner CSEs around AGB stars, including the pulsating layers previous to grain formation and outer regions where the fast expansion characteristic of such envelopes is already present. The analysis of the pumping mechanism of SiO masers and of the physical conditions in the emitting clumps requires accurate maps of the various lines, which show different excitation requirements. A large observational effort is being done to obtain (quasi-)simultaneous multiline data at the highest spatial resolution, using VLBI techniques, which makes possible to compare the relative distribution of the maser lines. We present the state-of-the-art in the field, and discuss preliminary results of SiO masers observed with the Global Millimeter VLBI Array (GMVA) which provide a new view into the physics of these AGB envelopes. The participation of ALMA in these VLBI arrays will boost the study of these masers, at higher frequencies.
Type de document :
Communication dans un congrès
Highlights on Spanish Astrophysics IX, Proceedings of the XII Scientific Meeting of the Spanish Astronomical Society held on July 18-22, 2016, in Bilbao, Spain, ISBN 978-84-606-8760-3. S. Arribas, A. Alonso-Herrero, F. Figueras, C. Hernández-Monteagudo, A. Sánchez-Lavega, S. Pérez-Hoyos (eds.), 2017 p. 361-366, Jul 2016, Bilbao, Spain. pp.361 - 366, 2017
Liste complète des métadonnées

https://hal.archives-ouvertes.fr/hal-01493760
Contributeur : Marie-Paule Pomies <>
Soumis le : mercredi 22 mars 2017 - 09:00:26
Dernière modification le : jeudi 23 mars 2017 - 01:06:10

Identifiants

Collections

Citation

F. Colomer, J. F. Desmurs, V. Bujarrabal, Alain Baudry, P. De Vicente, et al.. Studies of circumstellar shells in AGB stars by multifrequency (sub)mm-VLBI observations of maser emission. Highlights on Spanish Astrophysics IX, Proceedings of the XII Scientific Meeting of the Spanish Astronomical Society held on July 18-22, 2016, in Bilbao, Spain, ISBN 978-84-606-8760-3. S. Arribas, A. Alonso-Herrero, F. Figueras, C. Hernández-Monteagudo, A. Sánchez-Lavega, S. Pérez-Hoyos (eds.), 2017 p. 361-366, Jul 2016, Bilbao, Spain. pp.361 - 366, 2017. 〈hal-01493760〉

Partager

Métriques

Consultations de la notice

82