Comparison of Fig. 5 for different TNG50 resolution runs. The solid line indicates TNG50-4, the dash-dotted line TNG50-3, the dashed line TNG50-2, and the dotted line TNG50-1. The blue color represents the in situ stellar mass fraction of Milky Way-like central galaxies for tracers in the main progenitor, orange is the mass fraction for tracers in other galaxies, and green is the mass fraction for tracers in the IGM.