Nearby radio-loud galaxies 2. The map is the result of a 12-hr WSRT observation at 1.4 GHz. It beautifully shows the extended radio lobes, the radio core and two jet-like structures emanating from this core. The two unresolved sources alongside the giant are most likely unrelated radio sources.
Theoretical models predict a decline in the radio power as radio sources increase in size.
The rate of decrease of radio power is expected to grow for sources larger than 1 Mpc, but this predicted effect could never be properly tested observationally due to the lack of decent samples of such large sources. With Schoenmakers' sample of GRSs it has been possible to include sources larger than 1 Mpc in size in a fitting procedure to investigate the behaviour of the radio power of such sources. It shows that the inner structure is a double-lobed radio source itself. Schoenmakers et al. have also investigated the optical emission-line properties of their sample of GRSs, and the correlations of these with radio properties. For this purpose they have made extensive use of the 2.5-m INT telescope on La Palma.