Published online by Cambridge University Press: 14 August 2015
One of the most striking properties of the radio galaxies is the predominance of a symmetrical double lobed structure. Any model to explain the energy release and collimation in radio galaxies must be able to produce this symmetry as the normal morphology. Although this large scale symmetry in radio galaxies is a well known phenomenon, I feel it is worth reemphasising since our current attention is more sharply focussed on the small scale and often much less symmetric structures which are seen with the higher resolution radio telescopes (VLB, VLA etc).