Ultraviolet Imaging Polarimetry of Narrow-Line Radio Galaxies

Abstract

In an examination of the unification of radio galaxies and quasars, we obtained UV polarization images of eight narrow-line radio galaxies (NLRGs) with the Faint Object Camera on board the Hubble Space Telescope (HST). By observing in the rest ultraviolet, we can measure the polarization of the active nucleus with little contamination from unpolarized host-galaxy starlight. If, as the unified model predicts, NLRGs are really quasars with their jets lying in the sky plane, we expect to find elongated continua and large polarizations, with the E-vector perpendicular to the UV extent. The observations presented in this paper confirm both of these predictions.