Linking the Scales of Star Formation
Understanding galaxy evolution requires understanding star formation and its dependence on the local environment, spanning the scales from individual stars to kpc-size structures. The physical conditions within galaxies determine the formation of stars, star clusters, and larger structures, and their subsequent evolution.
HST observations of external galaxies have enabled the characterization of the young stellar populations with unprecedented accuracy and detail, thus aiding the census and description of those populations. These observations are being used to quantify the spatial distribution and clustering of young stars, and investigate the impact and imprint of the physical conditions of both the local and global environment on the formation and evolution of the multi-scale structures. I will concentrate mainly on the results of the Legacy ExtraGalactic UV Survey (LEGUS), an HST Treasury program that is investigating these issues using multi-color imaging, from the near-UV to the I, of a sample of nearby galaxies.