Redshift of the Radio Source 3C 48.

The radio source 3C 48 has been announced to be a star because of its small radio diameter and stellar appearance on direct plates. The recent discovery of the Balmer series in 3C 273 by Schmidt and Oke and the consequent large redshift AX/N0 of 0.158 suggests the possibility of a large redshift for 3C 48. On this basis a number of emission lines have been identified with lines of Mg II, ENe IIIJ, ENe v~, and EO IIJ. The redshift is 0.3675 or 110 200 km/sec. The possibility that the source is a nearby ultra- dense star of radius near 10 km and containing neutrons is ruled out from a spectroscopic point of view. Interpreting 3C 48 as the core of a peculiar galaxy, the distance is estimated to be 1.1 X 10~ pc. The absolute visual magnitude, corrected for red- shift effects, may be as bright as -26.3, at least 10 times brighter than the brightest elliptical galaxies. In the visual spectrum 3C 48 radiates about 50 times more powerfully than 3C 295 or Cyg A, but cqmparably with 3C 273. As a radio source 3C 48 is rather similar to 3C 295 and Cyg A. Due to its small angular diameter the surface brightness is very high. The integrated radio emission of 3C 48 is comparable with that from 3C 295, being 4X 10~~ ergs/sec. At a distance of 1.1 X 10~ pc the radio and optical emission must be confined within a diameter 5500 pc.