6533b7d4fe1ef96bd1261dea

RESEARCH PRODUCT

The Redshift Distribution of Flat-Spectrum Radio Sources

E. E. FalcoJ. LeharJ. A. MuñozChristopher S. KochanekEvencio Mediavilla

subject

PhysicsAstrophysics::High Energy Astrophysical PhenomenaAstrophysics (astro-ph)FluxFOS: Physical sciencesAstronomy and AstrophysicsQuasarAstrophysicsCosmological modelAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysicsSample (graphics)RedshiftDistribution (mathematics)Space and Planetary ScienceRange (statistics)Astrophysics::Galaxy Astrophysics

description

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.

yearjournalcountryeditionlanguage
2003-05-20
10.1086/377077http://arxiv.org/abs/astro-ph/0305382