A population-based approach to understanding radio AGN feedback with LOFAR: The LoTSS Deep Fields

TL;DR

This study uses a semi-analytic model to analyze the evolution of radio AGN jet powers across cosmic time, leveraging LOFAR data to improve understanding of AGN feedback in galaxy evolution.

Contribution

It introduces a physically motivated semi-analytic approach to infer radio AGN kinetic powers, incorporating source size, environment, and lifetime considerations, expanding analysis to a large sample.

Findings

Total kinetic power output is $ ext{~}10^{32}$-$10^{33}$ W Mpc$^{-3}$ across redshifts.

Population dominated by short-lived, lower-power sources.

Moderate positive evolution of power output from $z$=0 to 1, little change from $z$=1 to 2.

Abstract

Feedback from radio AGN jets is regularly implemented into contemporary models of galaxy evolution to offset radiative cooling in the large-scale environments in which they typically reside. While previous studies suggest that the total kinetic power output from radio AGN is sufficient for this purpose, many have relied on jet-power estimation from radio luminosities using generalised scaling relations that neglect additional information such as source size and environment. We here infer the cosmic evolution of radio AGN kinetic jet powers using a physically motivated semi-analytic model for the first time. Initial analysis on a sample of 619 radio AGN at $z < 2.5$ from LoTSS Deep Field and International LOFAR Telescope images of the Lockman Hole implies a population dominated by short-lived sources typically of lower jet power. After incorporating weighting towards shorter lifetimes in the inference models, we utilise ELAIS-N1 and Bo\"otes LoTSS Deep Field data to expand our analysis to a much larger sample of 5,187 objects, deriving jet kinetic luminosity functions and integrated kinetic luminosity densities for the radio AGN population out to $z = 2.5$. In broad agreement with previous results in the literature, we find the total power output per comoving volume to be $\sim$10$^{32}-$10$^{33}$ W Mpc$^{-3}$ across the full redshift range, with some suggestions of moderate positive evolution from $z$ = 0$-$1 and little evolution from $z$ = 1$-$2. These values are compatible with expectations from some cosmological models, providing strong evidence for the viability of feedback from radio AGN jets across cosmic time.