Using Hα morphology and surface brightness fluctuations to age-date star clusters in M83

We use new WFC3 observations of the nearby grand-design spiral galaxy M83 to develop two independent methods for estimating the ages of young star clusters. The first method uses the physical extent and morphology of Hα emission to estimate the ages of clusters younger than τ ≈ 10 Myr. It is based on the simple premise that the gas in very young (τ 10 Myr) clusters. A by-product of this study is the identification of 22 "single-star" H II regions in M83, with central stars having ages ≈4 Myr.