Possible Local Spiral Galaxy Counterparts to Compact Blue Galaxies at Intermediate Redshift

Abstract

We identify nearby disk galaxies with optical structural parameters similar to those of intermediate-redshift compact blue galaxies. By comparing H I and optical emission line widths, we show that the optical widths substantially underestimate the true kinematic widths of the local galaxies. By analogy, optical emission line widths may underrepresent the masses of intermediate-z compact objects. For the nearby galaxies, the compact blue morphology is the result of tidally triggered central star formation; we argue that interactions and minor mergers may cause apparently compact morphology at higher redshift.