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OATS-DAUT SEMINAR
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Speaker:
Giuseppe Bono (INAF-Osservatorio Astronomico di Roma)
Title: Omega Centauri: the possible link between globular clusters
and dwarf galaxies
Date: Wednesday, February 28th, 2007
Time: 12:00 noon
Venue: Villa Bazzoni
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Abstract:
Omega Centauri is one of the most interesting and puzzling Galactic
stellar system. According to several empirical evidence (kinematics,
total mass, spread in chemical composition) this system has been
considered the relic of a dwarf spheroidal galaxy. However, the
mass-to-light ratio and the velocity dispersion are quite typical of
Galactic globular clusters. We present new star counts of evolved
stellar tracers in Omega Centauri based on deep (ACS@HST) and wide
(WFI@2.2m ESO/MPI) multiband photometric investigations. In
particular, we compare observed star counts with evolutionary
lifetimes predicted by canonical and He-enriched stellar structures.
Finally, we briefly mention a few extragalactic implications of
He-enriched stellar populations.
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