The Star Clusters of the Small Magellanic Cloud: Age Distribution

Abstract

We present age measurements for 195 star clusters in the Small Magellanic Cloud based on comparison of integrated colors measured from the Magellanic Clouds Photometric Survey with models of simple stellar populations. We find that the modeled nonuniform changes of cluster colors with age can lead to spurious age peaks in the cluster age distribution, that the observed numbers of clusters with age, t, declines smoothly as t^{-2.1}, that for an assumed initial cluster mass function scaling as M^{-2} the dependence of the cluster disruption time on mass is proportional to M^{0.48}, that despite the apparent abundance of young clusters the dominant epoch of cluster formation was the initial one, and that there are significant differences in the spatial distribution of clusters of different ages. Because of limited precision in our age measurements, we cannot address the question of detailed correspondence between the cluster age function and the field star formation history. However, this sample provides an initial guide for which clusters to target in more detailed studies of specific age intervals.

11 pages (emulateapj), accepted for publication in the Astronomical Journal. Electronic tables available at: http://ngala.as.arizona.edu/dennis/rafelski.html