H IIRegion Statistics in Barred and Non-Barred Galaxies
Abstract
We present new high quality Ha continuum-subtracted images of the grand design galaxies NGC 157, NGC 3631, NGC 6764, and NGC 6951, two of them barred and two non-barred, and describe the statistical properties of the HII regions. We have determined the positions, angular sizes and fluxes of individual HII regions, and construct luminosity functions and diameter and density distributions. We find no significant differences between arm and interarm HII region properties, or between the barred and non-barred galaxies. This paper summarizes work described in more detail by Rozas et al (1995).