Optical spectropolarimetry of radio galaxies

This project is a search for relationships between radio and optical properties of radio galaxies. A set of 6 cm radio maps was made with the VLA, and many flux and polarization spectra were taken with the Lick 3 m telescope. The paper presents the spectropolarimetry and its relation to the radio structures. Quiescent quasar optical polarizations are all or nearly all aligned with the associated radio structure axes, Seyfert 1 polarizations tend to align with the radio sources, and Seyfert 2 polarizations are perpendicular to the radio axes. Among radio galaxies there is a significant excess of parallel objects. Among those which are not aligned, several show a perpendicular relationship. As examples of the latter case, extensive data for 3C 234 and 3C 382 are discussed and possible polarization mechanisms are modeled.