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The Redshift Distribution of Flat-Spectrum Radio Sources

J. A. Munoz·E. E. Falco·C. S. Kochanek·J. Lehar·E. Mediavilla
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Abstract

The redshift distribution of flat-spectrum radio sources with 5 GHz flux densities S>5 mJy is a key component in using current radio lens surveys to probe the cosmological model. We have constructed the first flat-spectrum radio sample in the flux density range 3-20 mJy. Our new sample has 33 sources; we have determined the redshifts of 14 of these (42% complete). The low mean redshift, ~0.75, of our faintest sample needs to be confirmed by further observations to improve the sample completeness. We also increased the redshift completeness of several surveys of brighter flat-spectrum sources. While the mean redshift, ~1.1 of flat-spectrum samples fainter than 1 Jy is nearly constant, the fraction of the sources identifiable as quasars steadily drops from ~80% to ~10% as the flux density of the sources decreases.

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J. A. Munoz, E. E. Falco, C. S. Kochanek, J. Lehar, E. Mediavilla. 2003-05-20. The Redshift Distribution of Flat-Spectrum Radio Sources. https://doi.org/10.1086/377077

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