Ultraviolet morphologies of nearby barred and unbarred spiral galaxies

Abstract

Deep high-resolution imaging of galaxies at high-redshift has revealed a remarkable diversity of emission structures in the restframe ultraviolet. To better understand these remote and primeval realms, it is important to compare them with UV-emitting counterparts in the local universe. As part of two Spacelab/Astro missions, the Ultraviolet Imaging Telescope (UIT) has obtained wide-field (40-arcmin), well-resolved (3 arcsec) images of ∼50 nearby galaxies in the vacuum ultraviolet. Followup groundbased imaging at UBVRI and Hα bands has been completed for most of the well-resolved galaxies. Analysis of a small subset of these galaxies has revealed strong variations in the emission morphologies as a function of restframe wavelength. In the present study, we compare the UV morphologies of barred and unbarred spiral galaxies as a function of Hubble type and absolute luminosity. Radial extents are measured relative to their visible counterparts, and characteristic UV emission structures are identified (e.g. rin...