Large Radio Sources Research Articles

Optical Identification of PKS 0320–37

LU1 has suggested that the large extended radio source PKS 0320–37 (Fornax A), identified for many years with the tenth magnitude SO galaxy NGC 1316 (ref. 2), should really be identified with a seventeenth magnitude blue stellar object. We propose to show here why this new identification should not be accepted.

Model for the Evolution of Extended Radio Sources

Large radio sources are influenced by the intergalactic medium and the cosmic black body radiation, both of which depend on red-shift in a predictable way. The type of source evolution implied by the radio data can be fitted by a simple model. This topic links with the X-ray background and the intergalactic cosmic ray density.