The Young Intercloud Population. I. Distances and Ages

Abstract

Deep BV CCD photometry has been used to characterize the properties of the young stellar population in the outer Small Magellanic Cloud (SMC) wing and in the bridge between the Magellanic Clouds. Our observations include targets that have not been previously observed and reach 2 mag fainter than data presented in a recent article by Grondin et al. They permit us to determine simultaneously, for an assumed abundance, the color excess and the distance of each association. Distances decrease from west to east and are compatible with a stellar bridge stretching from the SMC wing to the Large Magellanic Cloud. We confirm earlier findings that two associations, close in the sky, are indeed at a distance of ~5 kpc apart along the line of sight. The ages of the observed main sequences indicate that a burst of star formation occurred between 10 and 25 Myr ago. The star formation started earlier in the SMC wing, where evolved main-sequence stars of some 60 Myr are seen. No age gradient is seen across the 10 kpc bridge. Magnitude and color of many more bright main-sequence stars would be needed to better define the turnoffs and to determine ages more reliably.