Radio Morphologies, Types
Compact Sources (arcsecond scales and smaller)
Extended Sources (Fanaroff-Riley 1974 classes) and
can be very large (many arcminutes, up to Mpc)
FR I, tend to be lower power, continuous, jets
BL Lacs, radio galaxies
FR II, higher power, edge-brightened lobes
Quasars, radio galaxies
Other stuff.  More messes, oh yes!  Messes in deep space.
Optical IDs
Tough game historically – point sources, (elliptical) galaxies