The evolution of the galaxy stellar mass function and star formation rates in thecolibresimulations from redshift 17 to 0

We investigate the evolution of the galaxy stellar mass function (GSMF) and star formation rates (SFRs) across cosmic time in the colibre simulations of galaxy formation. colibre includes a multiphase interstellar medium, radiative cooling rates coupled to a model for the evolution of dust grains, and employs prescriptions for stellar and active galactic nucleus (AGN) feedback calibrated to reproduce the (Formula presented) observed GSMF and stellar mass–size relation. We present the evolution of the GSMF from simulations at three resolutions: (Formula presented), (Formula presented), and (Formula presented), in cosmological volumes of up to (Formula presented), (Formula presented), and (Formula presented) cMpc(Formula presented), respectively. We demonstrate that colibre is consistent with the observed GSMF over the full redshift range for which there are observations to compare with ((Formula presented) ), with maximum systematic deviations of (Formula presented) dex reached at (Formula presented). We also examine the evolution of the star-forming main sequence, cosmic SFR density, stellar mass density, and galaxy quenched fraction, making predictions for both the fiducial colibre model with thermally driven AGN feedback and its variant with hybrid (thermal + kinetic jet) AGN feedback, and finding good agreement with observations. Notably, we show that colibre matches the number density of massive quiescent galaxies at high redshifts reported by James Webb Space Telescope (JWST), while predicting a stellar-to-halo mass relation that evolves little with redshift. We conclude that neither a redshift-dependent star formation efficiency, nor a variable stellar initial mass function, nor a deviation from the (Formula presented) cold dark matter model is necessary to reproduce the high-redshift JWST stellar masses and SFRs.