[SEMINARI] [SEMIMARI] Masers in Evolved Stars, Jean-Fran çois Desmurs

[Enric Marco]

Title: Masers in Evolved Stars

By: Jean-François Desmurs

From: Observatorio Astronómico Nacional, Madrid.

Where: Seminari del departament d'Astronomia i Astrofísica

Date: Dimecres 07 novembre 2012

Hour: 15:00

Abstract

Asymptotic Giant Branch (AGB) stars are the final evolution stage of
low and intermediate mass stars. During this phase, they lose a lot of
matter in the form of stellar winds. As the atmosphere of these stars
is enriched by convection from the elements synthesized in their core,
this mass loss enriches the interstellar medium of the Galaxy in heavy
elements, oxygen, carbon, dust...  Astrophysical masers are
characterized by showing very large brightness equivalent
temperatures. This property of the maser emission has been extensively
used to probe the inner shells of the thick circumstellar envelopes
that surrounds AGB and post-AGB sources. They provide excellent
tracers of the dynamic of the envelope at different distances from the
central stars.  These regions are of particular interest, since it is
where the processes of dust formation and gas acceleration
(responsible for the mass loss of the star and the formation of the
envelope) occur.  I will discuss the different circumstellar masers
observed and how we can use them as astronomical tools to probe
in-situ different physical parameters.
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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
www.uv.es/marco
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