B Dias Poster

Self-Consistent Physical Parameters for 5 Intermediate-age SMC Stellar Clusters from CMD Modeling
B. Dias (IAG-USP/ESO), L. Kerber, B. Barbuy, B. Santiago, S. Ortolani, and E. Balbinot

Stellar clusters in the Small Magellanic Cloud are fundamental pieces to study the chemical and dynamical evolution of this neighboring dwarf galaxy, enabling inspection of a large period covering ~10 Gyr. The main goals of this work are the derivation of age, metallicity, distance modulus, reddening, core radius and central density profile for each cluster, and place them in the context of the Small Cloud evolution. The studied clusters are: AM 3, HW 1, HW 34, HW 40, Lindsay 2, and Lindsay 3, where HW 1, HW 34, and Lindsay 2 are studied for the first time. Optical colour-magnitude diagrams (V, B-V CMDs) and radial density profiles were built from images obtained with the 4.1m SOAR telescope, reaching V~23. The determination of structural parameters were carried out applying King profile fitting. The other parameters were derived in a self-consistent way by means of isochrone fitting, which uses the likelihood statistics to identify the synthetic CMDs that best reproduce the observed ones. Membership probabilities were determined comparing the cluster and control field CMDs. Completeness and photometric uncertainties were obtained performing artificial star tests. The results confirm that these clusters (except HW 34, identified as a field fluctuation) are intermediate-age clusters, with ages between ~1 and ~5 Gyr. Furthermore HW1, HW40 and Lindsay 2 were identified as metal-poor clusters with metallicity values lower than expected from the age-metallicity relation by Pagel & Tautvaisiene (1998). In particular HW 1 and Lindsay 2 are located in a region that we called West Halo.