The chemical composition of the Small Magellanic Cloud

Abstract: The Small Magellanic Cloud is a close, irregular galaxy that has experienced a complex star formation history due to the strong interactions occurred both with the Large Magellanic Cloud and the Galaxy. Despite its importance, the chemical composition of its stellar populations older than 1-2 Gyr is still poorly investigated. I present the first results of a spectroscopic survey of 200 Small Magellanic Cloud giant stars performed with FLAMES@VLT. The derived metallicity distribution peaks at [Fe/H] -0.9/-1.0 dex, with a secondary peak at [Fe/H] -0.6 dex. All these stars show [alpha/Fe] abundance ratios that are solar or mildly enhanced (+0.1 dex). Also, three metal-poor stars (with [Fe/H] -2.5 dex and enhanced [alpha/Fe] ratios compatible with those of the Galactic Halo) have been detected in the outskirts of the SMC: these giants are the most metal-poor stars discovered so far in the Magellanic Clouds.