The Spatial Distribution and Cosmological Evolution of Scintillating Radio Sources

An analysis of the scintillation properties of complete samples of extragalactic radio sources indicates: (i) There exists a correlation between compact physical structure and high radio luminosity and redshift once allowance is made for several observational selection effects. (ii) Strongly scintillating radio sources exhibit strong cosmological evolution of the form inferred for quasars and powerful radio sources in general. The strong evolutionary effects are found in samples of both 3CR and 4C radio sources. (iii) Strongly scintillating radio galaxies exhibit strong cosmological evolution as previously inferred by Schmidt.