Selection of Luminous Galaxies at the Edge of the Universe

Abstract

The search and study of distant galaxies is crucial for the understanding of the very first stages in galactic evolution. One way to find such systems is by selecting sources strongly emitting at radio frequencies. Radio-loud galaxies can be promising distant candidates since they can be detected everywhere in the Universe with the current deep radio surveys. However, the best radio-galaxy high-z candidates may well be weakly or even not detected at other wavelengths. For this purpose, we address a sample of double-lobe candidate radio sources detected at 1.4 GHz by the Australian Telescope Compact Array (ATCA) in the Extended Chandra Deep Field South (α = 3^h32^m30^s, δ =  − 27^∘48^m20^s (J2000)). This region has also been surveyed by Spitzer Space Telescope in the infrared (IR) and by the Advanced Camera for Surveys (on board of Hubble Space Telescope) in the optical, both observations reaching enormous depths. Here, the results from comparing these two wavebands with the ATCA radio map are presented, aiming for a more restrict sample of high-z candidates. This study will improve with the advent of future facilities such as the Squared Kilometer Array or the Atacama Large Millimetre Array, providing deeper and better resolution radio/mm surveys or follow-up observations.