Gas density projections of model galaxy h070. The strength of the magnetic field is increasing from B_λ = 0.05 nG on the left to B_λ = 0.50 nG at the rightmost panels. The upper and lower rows represent all the models generated without primordial magnetic fields (ΛCDM), and with primordial magnetic fields (ΛCDM+PMFs) matter power spectrum, respectively. Snapshots are taken at redshift z = 9. The white circle shows the galactic region, which is traced in all time steps. The evolution of various galaxy quantities, such as the gas content, is evaluated inside this region with radius ∼1.5 virial radius of the dark matter halo. Panels have physical sides and depth of 256 kpc. The included gas mass represents the average mass of gas in the galactic region over the first 2 Gyr.