On the redshift - apparent diameter relation for radio sources.
Abstract
The redshift-apparent diameter (theta - z) relation for radio galaxies is extended to z of about 1.2 and compared with the same relation for quasars. It is shown that the two theta - z relations are identical and that the metric-diameter distributions of quasars and radio galaxies are also identical, if the quasar redshift is cosmological. The theta - z relation for radio sources in general is shown to be in conflict with the standard curves expected in Friedmann models, thus implying cosmological evolution for the source metric diameters. A possible discontinuity in such evolution at z of approximately 0.5 is briefly discussed.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- September 1977
- Bibcode:
- 1977A&A....60..321G
- Keywords:
-
- Cosmology;
- Quasars;
- Radio Galaxies;
- Radio Sources (Astronomy);
- Red Shift;
- Astrometry;
- Astronomical Models;
- Diameters;
- Galactic Evolution;
- Size Determination;
- Astrophysics