A NEW ESTIMATE OF THE DENSITY AND INTENSITY OF EXTRAGALACTIC RADIO SOURCES

1963 ◽  
Vol 41 (5) ◽  
pp. 737-741
Author(s):  
G. A. Harrower ◽  
M. J. Watson
Keyword(s):  
Steady State ◽  
Statistical Analysis ◽  
Intensity Factor ◽  
Theoretical Curve ◽  
Radio Sources ◽  
Cosmic Radio ◽  
Factor B ◽  
Steady State Analysis ◽  
Extragalactic Radio Sources ◽  
Best Fit

The recent availability, through a statistical analysis of the Cambridge measurements of cosmic radio sources, of a source-count curve extended to distances at which the effect of recessional velocity is clearly evident in the measurements, has prompted the following comparison of this measured source-count curve with a theoretical curve based on a steady-state analysis. A best fit of measurements and theory allows values of proper density of sources ρ0 and intensity factor b to be estimated independently. The results obtained are ρ0 = 35 × 10−74 sources per cubic meter and b = 11 × 1025 (MKS units).

scholarly journals The Flux Density-Angular Size Distribution for Extragalactic Radio Sources

1977 ◽  
Vol 74 ◽  
pp. 125-132 ◽  
Author(s):  
G. Swarup ◽  
C. R. Subrahmanya
Keyword(s):  
Size Distribution ◽  
Flux Density ◽  
Angular Size ◽  
Evolutionary Model ◽  
Radio Sources ◽  
Extragalactic Radio Sources ◽  
Size Evolution ◽  
Theoretical Predictions ◽  
Best Fit ◽  
Remarkable Agreement

The median values of angular sizes of weak extragalactic radio sources, the flux densities of which lie in the range of about 0. 3 to 5 Jy at 327 MHz, have been determined for a new sample of 119 sources observed during 1973-74, and agree well with the value of about 10 arc sec determined earlier by Swarup (1975). For 8 different flux density ranges, the angular size distribution for the All-sky, 3CR and Ooty radio sources have been compared with theoretical predictions based on the evolutionary model by Kapahi (1975) and show a remarkable agreement with his model except that the best fit is found for a linear size evolution proportional to (l+z)−1.

scholarly journals Statistical Analysis of Observations of a Complete Sample of Compact Extragalactic Radio Sources

1996 ◽  
Vol 175 ◽  
pp. 97-98
Author(s):  
Y.Y. Kovalev
Keyword(s):  
Statistical Analysis ◽  
Radio Sources ◽  
Statistical Distributions ◽  
Turnover Frequency ◽  
Complete Sample ◽  
Extragalactic Radio Sources ◽  
Bl Lacs

Here are analyzed the results of instantaneous multifrequency observations for a complete sample of 113 extragalactic radio sources (see the paper by Yu.A. Kovalev et al. in these Proceedings) with declinations −30° ÷ 43° from the VLBI–survey. It is tested the hypothesis that quasars and BL Lacs have different nature. Statistical distributions for the turnover flux, turnover frequency, spectral indexes, and other parameters are analyzed.

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