• galaxies: groups: general;
  • galaxies: jets;
  • cosmology: observations;
  • large scale structure of Universe;
  • radio continuum: galaxies


The distributions of galaxies in the environments of 16 large radio sources have been examined using the Sloan Digital Sky Survey (SDSS). In the giant radio galaxy J1552+2005 (3C 326) which has the highest arm-length ratio, the shorter arm is found to interact with a group of galaxies which forms part of a filamentary structure. Although most large sources occur in regions of low galaxy density, the shorter arm is brighter in most cases suggesting asymmetries in the intergalactic medium which may not be apparent in the distribution of galaxies. In two cases with strong and variable cores, J0313+4120 and J1147+3501, the large flux density asymmetries are possibly also caused by the effects of relativistic motion.