Abstract details

The Small Magellanic Cloud (SMC) is the only dwarf galaxy in the Local Group known to have formed and preserved populous star clusters continuously over the past 12 Gyr. These clusters provide a unique, closely spaced set of single-age, single-metallicity tracers for a detailed study of the SMC's age-metallicity relation. Spectroscopic metallicity measurements, however, exist only for 6 of its clusters. Here we present metallicities for 10 additional SMC clusters based on Ca II triplet observations. Our sample comprises clusters spanning an age range of 12 Gyr. Complemented by accurate ages from deep HST/ACS photometry these objects provide us with a well-sampled, well-defined age-metallicity relation. We discuss the resulting chemical evolution history of the SMC and the importance of infall and outflows. We also address the question of the magnitude of metallicity spreads at a given age.