Star formation in disk galaxies

We present results, some preliminary, from a major new study of the star formation properties of a sample of nearby disk galaxies (Ferguson, PhD thesis). Our emphasis is on the faint outer regions of disks. H-alpha images, combined with broad-band images and spectroscopy of HII regions, constrain the present and past star formation rates and chemical enrichment. These data also allow study of faint diffuse ionized gas, which traces the influence of massive stars on their environment, and the structure of the interstellar medium.