Pc-scale study of radio galaxies and BL Lacs

Abstract We study two aspects of the differences between Active Galactic Nuclei (AGN) of the two Fanaroff–Riley types in order to investigate the causes of the F–R divide. We: (a) contrast the properties of the optical cores in beamed and unbeamed AGN of the two types, incorporating Hubble Space Telescope measurements of the unbeamed objects, and (b) contrast the nuclear magnetic field geometry of the beamed AGN of the two types using Very Long Baseline Polarimetry.