The distribution of mass components in simulated disc galaxies

Using 22 hydrodynamical simulated galaxies in a ΛCDM (Λ cold dark matter) 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 discs. This implies that the simulations, which span the range 52 < V_flat < 222 km s⁻¹, where V_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.