Evolution of AGN Across Cosmic Epochs with the SKAO

Abstract

Understanding the evolution of active galactic nuclei (AGN) and their host galaxies across cosmic epochs is one of the key science drivers of extragalactic astronomy. The detection of AGN residing in dusty environments and at high redshifts is difficult due to obscuration and faintness which poses a challenge in understanding AGN evolution across cosmic time. Deep radio continuum surveys (rms noise $<$ 1 $μ$Jy~beam$^{-1}$) from the Square Kilometre Array Observatory (SKAO) will be an efficient means to detect and study a broad population of AGN across cosmic history. In this chapter, we present radio luminosity functions, source counts, and detection rates of AGN based on the SKAO simulated radio source catalogues. We demonstrate that the SKA-Mid multi-tiered surveys, in particular, reaching sub-$μ$Jy depths, will allow us to characterise the bulk of the radio-AGN complete down to $L_{\rm{1.4\,GHz}} \sim 10^{23}\,\rm{W\,Hz^{-1}}$ and enable us to probe the evolution of radio-AGN across a wide range of luminosities and all galaxy environments up to $z \sim 6$. Overall, our work highlights the importance of deep multi-tiered SKAO radio continuum surveys for studying the evolution of radio-AGN activity across cosmic time.