A. Piatti Abstract

The Magellanic Clouds' Star Cluster Populations: The SMC

A. E. Piatti (Observatorio Astronómico de Córdoba)

We present results based on observations carried out with the CTIO 4m Blanco telescope and the MOSAIC II camera attached of a large sample of unstudied or poorly studied candidate star clusters in the Small Magellanic Cloud (SMC). The respective color magnitude diagrams (CMDs) were cleaned of the unavoidable star field contamination by taking advantage of a procedure that makes use of variable size CMD cells. This method has shown to be able to eliminate stochastic effects in the cluster CMDs caused by the presence of isolated bright stars, as well as to make a finer cleaning in the most populous CMD regions. Our results suggest that a percentage of the studied candidate star clusters would appear to be genuine physical systems. In this sense, the ages previously derived for some of them mostly reflect those of the composite stellar populations of the SMC field. Finally, we used the spatial distribution in the SMC of possible non-clusters to statistically decontaminate that of the SMC cluster system. We found that there is no clear difference between expected and observed cluster spatial distributions, although it would become significant at a 2 sigma level in the central regions, if the asterisms were increased up to 20 per cent.