CaII triplet spectroscopy of Small Magellanic Cloud red giants. II. Abundances for a sample of field stars

M.C. PARISI, D. GEISLER, A.J. G A. SARAJEDINI

ASTRONOMICAL JOURNAL

IOP PUBLISHING LTD

Lugar: Washington; Año: 2010 vol. 139 p. 1168 - 1168

0004-6256

h3 align="center" />We have obtained metallicities of ~ 360 red giant stars distributed in 15 Small Magellanic Cloud (SMC) fields from near-infrared spectra covering the Ca II triplet lines using the VLT + FORS2. The errors of the derived [Fe/H] values range from 0.09 to 0.35 dex per star, with a mean of 0.17 dex. The metallicity distribution (MD) of the whole sample shows a mean value of [Fe/H] = -1.00 ± 0.02, with a dispersion of 0.32 ± 0.01, in agreement with global mean [Fe/H] values found in previous studies. We find no evidence of a metallicity gradient in the SMC. In fact, on analyzing the MD of each field, we derived mean values of [Fe/H] = -0.99 ± 0.08 and [Fe/H] = -1.02 ± 0.07 for fields located closer and farther than 4° from the center of the galaxy, respectively. In addition, there is a clear tendency for the field stars to be more metal-poor than the corresponding cluster they surround, independent of their positions in the galaxy and of the clusters´ age. We argue that