Speaker
Description
With the availability of new large area and deep 0.3" resolution LOFAR surveys in combination with Euclid imaging, it is now finally possible to carry out large statistical studies of the radio loud Active Galactic Nuclei (AGN) population across cosmic time in combination with host galaxy properties. Whereas previous studies were limited to z~2, constrained by either the depth of observations or the field of view of the instruments, modern facilities such as Euclid and LOFAR allow us to go beyond this border and determine the evolution of the radio-loud AGN population together with their host galaxy properties up to z~6.
With a new sample of 100,000 radio sources, cross-matched with optical data, obtained from the LOw Frequency ARray (LOFAR) Two Metre Sky Survey (LoTSS) Deep Fields, we can for the first time determine the evolution of the radio AGN population out to z~6. Specifically, we study the change in number density of radio AGN for different radio luminosity bins, which shows that AGN with higher radio luminosity peak at earlier times in density compared to their lower luminosity counterpart. Using host galaxy properties such as stellar mass and star formation rate, we investigate the difference in evolution between subpopulations as well and show that at different redshifts, these subpopulations have differing amounts of radio emission. The difference between these populations is interpreted as cosmic downsizing, where the most massive black holes form at earlier times than less massive ones and discuss the importance of our findings in the context of radio AGN feedback.
