2023/12/22 by B. Šlaus, V. Smolčić, Šlaus, B. +15 · 2 citations
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astronomy and Astrophysical Research #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena
paper · pdf · doi:10.48550/arxiv.2312.14683
openalex publication_date 2023/12/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We model the evolution of active galactic nuclei by constructing their radio luminosity functions. We use a set of surveys of varying area and depth, namely the deep COSMOS survey of 1,916 AGN sources, the wide shallow 3CRR, 7C and 6CE surveys, containing together 356 AGNs, and the intermediate XXL-North and South fields consisting of 899 and 1,484 sources, respectively. We also used the CENSORS, BRL, Wall & Peacock and Config surveys, consisting respectively of 150, 178, 233 and 230 sources. Together, these surveys numbered 5,446 AGN sources and constrained the luminosity functions at high redshift and over a wide range of luminosities (up to z ≈ 3 and log (L / \mathrmW Hz-1) ∈ [22,29]). We concentrate on parametric methods within the Bayesian framework and show that the luminosity-dependent density evolution (LDDE) model fits the data best, with evidence ratios varying from "strong" (>10) to "decisive" (>100) according to the Jeffreys interpretation. We determine the number density, luminosity density and kinetic luminosity density as a function of redshift, and observe a flattening of these functions at higher redshifts, not present in simpler models, which we explain by our use of the LDDE model. Finally, we divide our sample into subsets according to the stellar mass of the host galaxies in order to investigate a possible bimodality in evolution. We found a difference in LF shape and evolution between these subsets. All together, these findings point to a physical picture where the evolution and density of AGN cannot be explained well by simple models but require more complex models either via AGN sub-populations where the total AGN sample is divided into subsamples according to various properties such as, for example, optical properties and stellar mass, or via luminosity-dependent functions.