Evolution of faint radio sources in the VIDEO-XMM3 field

In this paper, we present a new investigation of the evolution of faint radio sources out to z similar to 2.5. We combine a 1 square degree Very Large Array radio survey, complete to a depth of 100 mu Jy, with accurate 10 band photometric redshifts from the following surveys: Visible and Infrared Survey Telescope for Astronomy Deep Extragalactic Observations and Canada-France-Hawaii Telescope Legacy Survey. The results indicate that the radio population experiences mild positive evolution out to z similar to 1.2 increasing their space density by a factor of similar to 3, consistent with results of several previous studies. Beyond z = 1.2, there is evidence of a slowing down of this evolution. Star-forming galaxies drive the more rapid evolution at low redshifts, z < 1.2, while more slowly evolving AGN populations dominate at higher redshifts resulting in a decline in the evolution of the radio luminosity function at z > 1.2. The evolution is best fitted by pure luminosity evolution with star-forming galaxies evolving as (1 + z)(2.47 +/- 0.12) and AGN as (1 + z)(1.18 +/- 0.21).