The MaGICC volume: reproducing statistical properties of high redshift galaxies

TL;DR

This study uses cosmological hydrodynamical simulations to reproduce key statistical properties of high-redshift galaxies, highlighting the importance of early stellar feedback combined with supernova feedback in galaxy formation.

Contribution

It demonstrates the effectiveness of a thermal feedback model in simulating high-redshift galaxy properties across various masses and morphologies, with insights into feedback limitations at high masses.

Findings

Good match with observed stellar mass-halo mass relation at high redshift

Accurate reproduction of the galaxy stellar mass function at low masses

Overprediction of stellar mass in massive galaxies at z=0

Abstract

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 ($z \ge 2$) including the stellar mass - halo mass ($M_\star - M_h$ ) relation, the Galaxy Stellar Mass Function (GSMF) at low masses ($M_\star \lt 5 \times 10^{10} M_\odot$ ) and the number density evolution of low mass galaxies. The poor match of $M_\star - M_h$ and the GSMF at high masses ($M_\star \ge 5 \times 10^{10} M_\odot$ ) indicates 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 $L_\star$ mass galaxy. Altogether our results suggest that early stellar feedback, in conjunction with supernovae feedback, plays a major role in regulating the properties of low mass galaxies at high redshift.