The unification of powerful quasars and radio galaxies and their
  relation to other massive galaxies
  The unification model for powerful radio galaxies and radio-loud quasars
postulates that these objects are intrinsically the same but viewed along
different angles. Herschel Space Observatory data permit the assessment of that
model in the far-infrared spectral window. We analyze photometry from Spitzer
and Herschel for the distant 3CR hosts, and find that radio galaxies and
quasars have different mid-infrared, but indistinguishable far-infrared colors.
Both these properties, the former being orientation dependent and the latter
orientation invariant, are in line with expectations from the unification
model. Adding powerful radio-quiet active galaxies and typical massive
star-forming galaxies to the analysis, we demonstrate that infrared colors not
only provide an orientation indicator, but can also distinguish active from
star-forming galaxies.
