The distribution of mass components in simulated disc galaxies

TL;DR

This study uses hydrodynamical simulations of disc galaxies to successfully replicate key observed relations, including the baryonic Tully-Fisher and mass discrepancy-acceleration relations, and matches the baryonic to halo mass relation.

Contribution

The paper demonstrates that cosmological hydrodynamical simulations can reproduce multiple observed galaxy scaling relations and the baryonic to halo mass relation.

Findings

Simulations recover the baryonic Tully-Fisher relation.

Simulations reproduce the mass discrepancy-acceleration relation.

First match of the baryonic to halo mass relation with simulated galaxies.

Abstract

Using 22 hydrodynamical simulated galaxies in a LCDM cosmological context we recover not only the observed baryonic Tully-Fisher relation, but also the observed "mass discrepancy--acceleration" relation, which reflects the distribution of the main components of the galaxies throughout their disks. This implies that the simulations, which span the range 52 < V$_{\rm flat}$ < 222 km/s where V$_{\rm flat}$ is the circular velocity at the flat part of the rotation curve, and match galaxy scaling relations, are able to recover the observed relations between the distributions of stars, gas and dark matter over the radial range for which we have observational rotation curve data. Furthermore, we explicitly match the observed baryonic to halo mass relation for the first time with simulated galaxies. We discuss our results in the context of the baryon cycle that is inherent in these simulations, and with regards to the effect of baryonic processes on the distribution of dark matter.