I. Basic data
INAF – Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122 Padova, Italy
2 Dipartimento di Astronomia, Università di Padova, Italy
3 CISAS, Università di Padova, Italy
Corresponding author: R. G. Gratton, email@example.com
Accepted: 17 March 2003
We present element-to-element abundance ratios measured from high dispersion spectra for 150 field subdwarfs and early subgiants with accurate Hipparcos parallaxes (errors <20%). For 50 stars new spectra were obtained with the UVES on Kueyen (VLT UT2), the McDonald 2.7 m telescope, and SARG at TNG. Additionally, literature equivalent widths were taken from the works by Nissen & Schuster, Fulbright, and Prochaska et al. to complement our data. The whole sample includes both thick disk and halo stars (and a few thin disk stars); most stars have metallicities in the range . We found our data, that of Nissen & Schuster, and that of Prochaska to be of comparable quality; results from Fulbright scatter a bit more, but they are still of very good quality and are extremely useful due to the large size of his sample. The results of the present analysis will be used in forthcoming papers to discuss the chemical properties of the dissipational collapse and accretion components of our Galaxy.
Key words: stars: abundances / stars: evolution / stars: population II / Galaxy: globular clusters: general
Based in part on data collected at the European Southern Observatory, Chile, at the MacDonald Observatory, Texas, USA, and at the Telescopio Nazionale Galileo, Canary Island, INAF, Italy-Spain.
© ESO, 2003