Visual impression of the spatial structure of the infall redshifts z_infall of tracers that reside in in situ stars at z = 0. Representative examples of a group, Milky Way-like, and dwarf galaxy (random orientations) are shown in the upper left, upper right, and lower left panels, respectively. Colors show the median z_infall along a projection that extends through the entire halo. The lower right panel quantifies these trends with radial profiles. Solid lines show (individual) profiles of the galaxies from the three previous panels, while dashed curves the medians of all galaxies in each mass bin. Overall, the core regions of more massive galaxies are made of stars that formed from gas that entered the halo at earlier times.