Compact Radio Sources, Quasars and Active Galactic Nuclei

Abstract

This paper reviews John G. Bolton's contributions to our understanding of compact radio sources associated with quasars and active galactic nuclei (AGNs), and his work leading to the discovery of quasars. Particular attention is given to the interpretation of the observed properties of quasars and AGNs within the framework of unified models which interpret the wide variety of observed properties as being the result of orientation rather than of any intrinsic differences.