Dating star clusters in the Small Magellanic Cloud by means of integrated spectra

Abstract

In this study flux-calibrated integrated spectra in the range (3600–6800) Å are presented for 16 concentrated star clusters in the Small Magellanic Cloud (SMC), approximately half of which constitute unstudied objects. We have estimated ages and foreground interstellar reddening values from the comparison of the line strengths and continuum distribution of the cluster spectra with those of template cluster spectra with known parameters. Most of the sample clusters are young blue clusters (6–50 Myr), while L28, NGC643 and L114 are found to be intermediate-age clusters (1–6 Gyr). One well known SMC cluster (NGC416) was observed for comparison purposes. The sample includes clusters in the surroundings and main body of the SMC, and the derived foreground reddening values are in the range 0.00≤ E(B−V)≤0.15. The present data also make up a cluster spectral library at SMC metallicity.