The Combined NVSS–FIRST Galaxies (CoNFIG) sample – II. Comparison of space densities in the Fanaroff–Riley dichotomy

• Published in: Monthly notices of the Royal Astronomical Society 2010-06, Vol.404 (4), p.1719-1732
• Main Authors: Gendre, M. A., Best, P. N., Wall, J. V.
• Format: Article
• Language: English
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; galaxies: active; galaxies: luminosity function; galaxies: luminosity function, mass function; galaxies: statistics; mass function; Radio astronomy; radio continuum: galaxies; Radio telescopes; Stars & galaxies; surveys
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2010.16413.x

This paper focuses on a comparison of the space densities of Fanaroff–Riley type I (FR I) and FR II sources at different epochs, with a particular focus on FR I sources. First, we present the concluding steps in constructing the Combined NVSS–FIRST Galaxies (CoNFIG) catalogue, including new Very Large Array observations, optical identifications and redshift estimates. The final catalogue consists of 859 sources over four samples (CoNFIG-1, -2, -3 and -4 with flux density limits of S1.4 GHz= 1.3, 0.8, 0.2 and 0.05 Jy, respectively). It is 95.7 per cent complete in radio morphology classification and 74.3 per cent of the sources have redshift data. Combining CoNFIG with complementary samples, the distribution and evolution of FR I and FR II sources are investigated. We find that FR I sources undergo mild evolution and that, at the same radio luminosity, FR I and FR II sources show similar space density enhancements in various redshift ranges, possibly implying a common evolution.