Accession Number : AD0734377

Title :   Counts of Intense Extragalactic Radio Sources at 1400 MHz,

Corporate Author : OWENS VALLEY RADIO OBSERVATORY PASADENA CALIF

Personal Author(s) : Bridle,A. H. ; Davis,M. M. ; Fomalont,E. B. ; Lequeux,J.

Report Date : 1971

Pagination or Media Count : 19

Abstract : The counts of discrete extragalactic radio sources at different levels of flux density, and their interpretation in terms of cosmological models, have been the subject of controversy for nearly fifteen years. Much discussion has centered on determinations of the exponent gamma of the number-flux density relation N(S) proportional to (S to the -gamma power), where N is the number of sources per steradian whose flux densities exceed S. Counts derived from surveys at frequencies below 500 MHz have indicated that gamma > 1.5 for the intense sources. In this paper the authors derive counts from accurate 1400 MHz observations of intense sources over a large area of the sky. It is shown that there is little evidence for cosmological evolution contingent on gamma > 1.5 for these sources, but that separation of the counts according to the surface brightness of the sources may lead to a cosmologically significant result. (Author)

Descriptors :   (*EXTRATERRESTRIAL RADIO WAVES, SOURCES), RADIO ASTRONOMY, ULTRAHIGH FREQUENCY, INTENSITY

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE