Abstract
ASSUMING that the red-shifts of quasars are cosmological, Longair1, and Roeder and Mitchell2, have suggested that the present available distribution of flux-densities at 178 Mc/s, S178, of quasars against red-shift implies that the radio luminosity, P, of quasars which exist at cosmic epoch t is a decreasing function of t. This would be an important conclusion for cosmology, because the natural inference is that the anomalous steep radio source counts are also due to this evolution in luminosity, rather than to any variation in the spatial density of sources. This conclusion seems premature, however, because the present available data for quasars can also be interpreted as the result of a decrease in the source density with t.
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ROWAN-ROBINSON, M. Density Evolution Hypothesis for Quasars. Nature 212, 1556–1557 (1966). https://doi.org/10.1038/2121556a0
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DOI: https://doi.org/10.1038/2121556a0
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