New candidate intermediate-age star clusters in the small magellanic cloud

Abstract

We present the results on the age and metallicity estimates of nine Small Magellanic Cloud (SMC) clusters (AM 3, HW 31, 40, 41, 42, 59, 63, L91 and NGC 339) obtained from CCD Washington CT1T2 photometry. We confirm AM 3 and NGC 339 as intermediate-age and metal-poor clusters, and report for the first time that the remaining seven clusters are also intermediate-age or old clusters (t ∼ 4.3–9.3 Gyr), which represents an increase of ≳60 per cent of the total known intermediate-age/old cluster population in the SMC. The studied clusters have metal contents ranging from intermediate metal-poor ([Fe/H] ≈−0.7 dex) down to metal-poor ([Fe/H] ≈−1.3 dex) values.