Radio properties of GPS and CSS sources: Galaxies versus quasars

On the basis of the different radio properties ( especially different radio morphologies) between GPS galaxies and GPS quasars, I suggest that GPS galaxies are a more homogeneous class mainly consisting of compact symmetric objects, while the majority of GPS quasars are an intrinsically different type of radio source, similar to the common flat spectrum radio sources. For CSS radio sources the difference between galaxies and quasars is less evident. This is interpreted as a bias correlated with size: samples of smaller objects are more likely to be contaminated by unrelated objects. This is consistent also with the high percentage of blazar/quasar objects present in a sample of the even smaller HFP radio sources.