The MaGICC volume: reproducing statistical properties of high-redshift galaxies

We present a cosmological hydrodynamical simulation of a representative volume of the Universe, as part of the Making Galaxies in a Cosmological Context (MaGICC) project. MaGICC uses a thermal implementation for supernova and early stellar feedback. This work tests the feedback model at lower resolution across a range of galaxy masses, morphologies and merger histories. The simulated sample compares well with observations of high-redshift galaxies (z ≥ 2) including the stellar mass–halo mass (M⋆-Mh) relation, the galaxy stellar mass function (GSMF) at low masses (M⋆ < 5 × 1010 M⊙) and the number density evolution of low-mass galaxies. The poor match of M⋆-Mh and the GSMF at high masses (M⋆ ≥ 5 × 1010 M⊙) indicates that supernova feedback is insufficient to limit star formation in these haloes. At z = 0, our model produces too many stars in massive galaxies and slightly underpredicts the stellar mass around L⋆ mass galaxy. Altogether our results suggest that early stellar feedback, in conjunction with supernova feedback, plays a major role in regulating the properties of low-mass galaxies at high redshift.