2017MNRAS.469.2517W

We employ the very large cosmological hydrodynamical simulation BlueTides to investigate the predicted properties of the galaxy population during the epoch of reionization (z > 8). BlueTides has a resolution and volume ((400/h ≃ 577)³ cMpc³) providing a population of galaxies that is well matched to depth and area of current observational surveys targeting the high-redshift Universe. At z = 8, BlueTides includes almost 160 000 galaxies with stellar masses >10⁸ M_☉. The population of galaxies predicted by BlueTides closely matches observational constraints on both the galaxy stellar mass function and far-UV (150 nm) luminosity function. Galaxies in BlueTides are characterized by rapidly increasing star formation histories. Specific star formation rates decrease with redshift though remain largely insensitive to stellar mass. As a result of the enhanced surface density of metals, more massive galaxies are predicted to have higher dust attenuation resulting in a significant steepening of the observed far-UV luminosity function at high luminosities. The contribution of active supermassive black holes (SMBHs) to the UV luminosities of galaxies with stellar masses 10^9–10 M_☉ is around 3 per cent on average. Approximately 25 per cent of galaxies with M_* ≃ 10¹⁰ M_☉ are predicted to have active SMBHs that contribute >10 per cent of the total UV luminosity.