The Phoenix Multiwavelength Deep Survey

Abstract

This thesis describes the Phoenix Deep Survey, a multiwavelength survey of a two-degree diameter region. Observations at 1.4 GHz and 843 MHz in the radio continuum, at R-, V-, H-, and K-bands in the optical and near-infrared, and of galaxy spectra, are analysed to investigate the nature of the faintest observable radio sources. A catalogue of 1079 radio sources is compiled from these observations, and optical counterparts for 541 of these radio sources are identified. Radio and optical source counts are predicted from models for luminosity functions and are compared with the observational source counts. Radio luminosity evolution at a rate of Q = 3.3 ± 0.8 for starburst galaxies, a rate consistent with other studies, is found to be required to match the observed radio source counts. The bivariate (radio/optical) luminosity function is also modelled and used to predict the bivariate source count distribution, for comparison with observation. The redshift distribution predicted from the bivariate luminosity function is investigated. It is established that, as anticipated from earlier studies, a larger proportion of sub-mJy radio sources are starburst galaxies than at higher flux densities, but there are still significant numbers of AGN sources present. The observational radio luminosity function is investigated, and several interesting sources are examined in more detail.