Space densities of radio AGN: The CoNFIG sample

TL;DR

This paper presents the CoNFIG survey, classifying radio AGN into FRI and FRII types, analyzing their luminosity functions, and exploring their evolution, morphology, and feedback mechanisms using radio and optical data.

Contribution

It provides a detailed classification and analysis of radio AGN populations, improving understanding of their evolution and the validity of unified schemes.

Findings

Distinct luminosity distributions for FRI and FRII sources.

Evidence supporting different evolutionary paths for the two populations.

Insights into the role of radio AGN in galaxy feedback mechanisms.

Abstract

The Combined NVSS-FIRST Galaxy (CoNFIG) survey was defined by selecting all sources with S_1.4GHz > 1.3Jy from the NRAO VLA Sky Survey (NVSS) in the north field of the Faint Images of the Radio Sky at Twenty-cm (FIRST) survey. We carried out FRI/FRII morphology classification from NVSS and FIRST survey data; to complete this process, new 8GHz VLA observations for 31 sources were obtained at 0.24 arcsec resolution. Optical identifications and redshift information were compiled for about ~80% of the 270 radio sources in the sample, the mean redshift being ~0.6. A major goal of this sample is a better definition of the individual luminosity distributions and source counts for FRI and FRII sources, in order to determine accurately the evolution of the luminosity function for both types. Amongst the aims are the issues of whether the two populations are really distinct, whether physical evolution schemes permit one type to evolve into the other, whether the dual-population unified scheme for radio AGN remains viable, and the role radio AGN - star-formation feedback mechanisms.