Cosmic evolution of radio-AGN feedback: confronting models with data

Radio-mode feedback is a key ingredient in galaxy formation and evolution models, required to reproduce the observed properties of massive galaxies in the local Universe. We study the cosmic evolution of radio-active galactic nuclei (AGN) feedback out to z similar to 2.5 using a sample of 9485 radio-excess AGN. We combine the evolving radio luminosity functions with a radio luminosity scaling relationship to estimate AGN jet kinetic powers and derive the cosmic evolution of the kinetic luminosity density, Omega(kin) (i.e. the volume-averaged heating output). Compared to all radio-AGN, low-excitation radio galaxies dominate the feedback activity out to z similar to 2.5, with both these populations showing a constant heating output of Omega(kin) approximate to(4 -5) x 10(32) W Mpc(-3) across 0.5 < z < 2.5. We compare our observations to predictions from semi-analytical and hydrodynamical simulations, which broadly match the observed evolution in Omega(kin), although their absolute normalization varies. Comparison to the Semi-Analytic Galaxy Evolution (SAGE ) model suggests that radio-AGN may provide sufficient heating to of fset radiati ve cooling losses, providing evidence for a self-re gulated AGN feedback c ycle. We inte grate the kinetic luminosity density across cosmic time to obtain the kinetic energy density output from AGN jets throughout cosmic history to be similar to 10(50) J Mpc(-3). Compared to AGN winds, the kinetic energy density from AGN jets dominates the energy budget at z less than or similar to 2; this suggests that AGN jets play an important role in AGN feedback across most of cosmic history.