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Elemental abundances as a function of kinematics in the Milky Way's disk

Pascal Girard·Caroline Soubiran
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Abstract

We present the results of our investigation of three samples kinematically representative of the thin and thick disks and the Hercules stream using the catalogue of Soubiran & Girard (2005). We have observed abundance trends and age distribution of each component. Our results show that the two disks are chemically well separated, they overlap greatly in metallicity and both show parallel decreasing trends of alpha elements with increasing metallicity, in the interval -0.80 < [Fe/H] < -0.30. The thick disk is clearly older than the thin disk with a tentative evidence of an Age-Metallicity Relation over 2-3 Gyr and a hiatus in star formation before the formation of the thin disk. In order to improve the statistics on the disk's abundance trends, we have developed an automatic code, TGMET{\Largeα}; to determine (Teff, logg, [Fe/H], [α/Fe]) for thousands of stellar spectra available in spectroscopic archives. We have assessed the performances of the algorithm for 350 spectra of stars being part of the abundance catalogue.

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Pascal Girard, Caroline Soubiran. 2006-01-20. Elemental abundances as a function of kinematics in the Milky Way's disk. https://arxiv.org/abs/astro-ph/0601472

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