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Symposium 241

Abstract details

High resolution spectral population models for solar and alpha-enhanced compositions
P. Coelho, G. Bruzual, S. Charlot, A. Weiss, B. Barbuy

In the last years, observations made by large international consortia made available hundreds of thousands of high-resolution spectra of galaxies in the local and distant Universe. The interpretation of these spectra in terms of stellar ages and metallicities is the key to reconstructing the star formation and chemical enrichment histories of the Universe. However, such interpretations have been hampered by the fact that current models rely on spectral libraries of observed stars in the Milky Way and Magellanic Clouds, which have solar metal-abundance ratios at all metallicities. In contrast, the spectra of external galaxies appear to often be dominated by stars with non-solar metal abundance ratios (e.g., [\alpha/Fe]). Although it is already available in the literature several stellar population models for the Lick/IDS indices considering variable chemical mixtures, we still lack full spectral energy distribution models at high resolutionand wider wavelength coverage. Those models are required if we want to exploitthe total amount of information contained in the mentioned observed galaxy spectra. We present here a work that is being done aiming at the development of such high resolution SED stellar population models with variable chemical mixtures. This work is a collaboration that includes CIDA, IAG, IAP and MPA institutes, and the models are constructed with an homogeneous and consistent set of synthetic stellar library and new stellar evolution models.

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