Three LMC Globular Clusters

With the advent of HST, it is possible to study the LMC globular clusters in similar detail to those in our own Galaxy. We can then probe the formation history of the LMC, placing constraints on the epoch of initial star formation and the duration and nature of globular cluster formation in the LMC halo. Using V, I WFPC2 photometry for three old, metal-poor LMC clusters (NGC 1466, NGC 2257 and Hodge 11) extending to ~ 3 magnitudes below the main-sequence turnoff, we compare their color-magnitude diagrams to those of local Galactic globulars. We find that the LMC clusters are as old as the Milky Way clusters. In addition, the relative ages of the LMC clusters themselves are the same to within 1 Gyr. Both the similar ages to Galactic globulars and the age spread within the LMC clusters are shown to be consistent with hierarchial clustering models of galaxy formation. We also present blue straggler statistics for our LMC clusters and compare them to Galactic globulars, in particular the outer halo clusters that have also been studied with HST.