Gas resolution (defined as the smoothing length of SPH particles) in the simulation Eris2k as a function of distance from the main halo center. The blue curve represents the median value in the radial bin, while the shaded area includes the variation from the 10th to the 90th percentile. The other two lines show the median resolution for a halo in Illustris TNG50 (M_halo ≃ 10^12.5 M_⊙) and the high-resolution simulation in Suresh et al. (2019; with 10th to 90th percentile variation).