The Horizon-AGN simulation: evolution of galaxy properties over cosmic time

TL;DR

The Horizon-AGN simulation accurately models galaxy evolution from early universe to present, matching observed stellar-mass growth, luminosity functions, and star formation history, highlighting the role of black hole feedback.

Contribution

This study demonstrates that Horizon-AGN, without tuning to local data, effectively reproduces galaxy properties over cosmic time, emphasizing the importance of AGN feedback in galaxy evolution.

Findings

Horizon-AGN agrees well with observed galaxy properties from z=6 to z=0.

Black hole feedback influences stellar-mass growth, especially in massive galaxies.

Simulation predicts galaxy evolution trends consistent with observational data.

Abstract

We compare the predictions of Horizon-AGN, a hydro-dynamical cosmological simulation that uses an adaptive mesh refinement code, to observational data in the redshift range 0<z<6. We study the reproduction, by the simulation, of quantities that trace the aggregate stellar-mass growth of galaxies over cosmic time: luminosity and stellar-mass functions, the star formation main sequence, rest-frame UV-optical-near infrared colours and the cosmic star-formation history. We show that Horizon-AGN, which is not tuned to reproduce the local Universe, produces good overall agreement with these quantities, from the present day to the epoch when the Universe was 5% of its current age. By comparison to Horizon-noAGN, a twin simulation without AGN feedback, we quantify how feedback from black holes is likely to help shape galaxy stellar-mass growth in the redshift range 0<z<6, particularly in the most massive galaxies. Our results demonstrate that Horizon-AGN successfully captures the evolutionary trends of observed galaxies over the lifetime of the Universe, making it an excellent tool for studying the processes that drive galaxy evolution and making predictions for the next generation of galaxy surveys.