Active galaxies - The redshift one 3CR galaxies

The 3CR radio galaxies exhibit the same strong cosmological evolutionary effects which are found in the population of active galaxies in general. HST, VLA and UKIRT observations have been made of an almost complete sample of 28 narrow-line 3CR radio galaxies in the redshifft interval 0.6<z>1.8 The HST images between the optical morphologies of the galaxies and the radio axes of the double radio sources, and these can be placed in an evolutionary sequence with increasing separation of the hot-spots of the radio structures. In the case of 3C 34, there is evedence for jet-induced star formation in a galaxy which lies in the path of the radio jet. It is suggested that similar processes may play a role in creating the aligned structures. The implications of these observations for understanding the nature of the galaxies associated with strong radio sources and the K-z relationship for 3CR radio galaxies are discussed.