SETI bioastro: Age and metallicity of Galactic clusters from full spectrum fitting

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Astrophysics, abstract
astro-ph/0702116

From: Mina Koleva [view email]

Date: Mon, 5 Feb 2007 14:53:30 GMT (36kb)

Age and metallicity of Galactic clusters from full spectrum fitting

Authors: Mina Koleva, Philippe Prugniel, Pierre Ocvirk, Damien Le Borgne

Comments: 2 pages; proceedings of IAU Symposium No. 241, "Stellar
Populations as Building Blocks of Galaxies", editors A. Vazdekis and R.
Peletier

We are using full spectrum fitting to determine the ages and metallicities
of Galactic clusters (M67 and globular clusters). We find that the method is
very accurate to measure the metallicity. Blue horizontal branches are well
identified as a 'young' sub-component, and the age of the 'old' component is
in fair agreement with CMD determinations.

http://arxiv.org/abs/astro-ph/0702116

Astrophysics, abstract
astro-ph/0702120

From: Annalisa Calamida [view email]

Date: Mon, 5 Feb 2007 16:58:08 GMT (94kb)

Metallicity distribution of Omega Cen Red Giants based on the Stroemgren m1
metallicity index

Authors: A. Calamida, G. Bono (OAR/INAF), L. M. Freyhammer (University of
Central Lancashire), F. Grundahl (Aarhus University), C. E. Corsi
(OAR/INAF), P. B. Stetson (DAO, HIA-NRC), R. Buonanno (Universita' di Roma
Tor Vergata), M. Hilker (ESO), T. Richtler (Universidad de Concepcion)

Comments: 4 pages, 3 figures. To appear in the Proceedings of IAU Symposium
241: "Stellar Populations as Building Blocks of Galaxies", 10-16 December,
2006 at La Palma, Canary Islands, Spain

We adopted uvby Stroemgren photometry to investigate the metallicity
distribution of Omega Cen Red Giant (RG) stars. We provided a new empirical
calibration of the Stroemgren m1 = (v-b)-(b-y) metallicity index based on
cluster stars. The new calibration has been applied to a sample of Omega Cen
RGs. The shape of the estimated metallicity distribution is clearly
asymmetric, with a sharp cut-off at low metallicities ([Fe/H] < -2.0) and a
metal-rich tail up to [Fe/H] ~ 0.0. Two main metallicity peaks have been
identified, around [Fe/H] ~ -1.9 and -1.3 dex, and a metal-rich shoulder at
~ 0.2 dex.

http://arxiv.org/abs/astro-ph/0702120

• Previous message: LARRY KLAES: "SETI bioastro: Multisite campaign on the open cluster M67. II. Evidence for solar-like oscillat"

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