MOJAVE: Monitoring of jets in AGN with VLBA experiments. IV. The parent luminosity function of radio-loud blazars

We use a complete sample of active galactic nuclei (AGN) selected on the basis of relativistically beamed 15 GHz radio flux density (MOJAVE: Monitoring of Jets in AGN with VLBA Experiments) to derive the parent radio luminosity function (RLF) of bright radio-selected blazar cores. We use a maximum likelihood method to fit a beamed RLF to the observed data and thereby recover the parameters of the intrinsic (unbeamed) RLF. We analyze two subsamples of theMOJAVE sample: the first contains only objects of known FR II class, with a total of 103 sources, and the second subsample adds 24 objects of uncertain FR class for a total of 127 sources. Both subsamples exclude four known FR I radio galaxies and two gigahertz-peaked spectrum sources. We obtain good fits to both subsamples using a single power law intrinsic RLF and a pure density evolution function of the form zexpf 1/2 z z0 ð Þ/ 1⁄2 g. We find that a previously reported break in the observed MOJAVE RLF actually arises from using incomplete bins (because of the luminosity cutoff ) across a steep and strongly evolving RLF, and does not reflect a break in the intrinsic RLF. The derived space density of the parent population of the FR II sources from the MOJAVE sample (with L15 GHz 1:3 ; 10 W Hz ) is approximately 1:6 ; 10 Gpc . Subject headingg s: BL Lacertae objects: general — galaxies: active — galaxies: evolution — galaxies: luminosity function, mass function — quasars: general