Two Types of Radio Galaxies: A New Approach
  We do not fully understand the dynamics and evolution of a radio galaxy. Models of classical double (Type II) sources are in a reasonable state, but these objects are rare. Non-type II sources (generically called Type I) are far more common, but much less well understood. In this paper I use the data to suggest possible new models for Type I sources, and discuss the physical questions which these new models raise. 
Jean Eilek (NM Tech)