Comparison of z = 0 ASTRID BHOFs with observational constraints and predictions from other simulations. We plot the ASTRID total and central full-population BHOFs, as well as the corresponding heavy-seed BHOFs. Local observational constraints from Z25 are shown alongside predictions from the EAGLE, SIMBA, Horizon-AGN, Illustris, TNG100, and TNG300 cosmological simulations, computed by H. Haidar et al. (2022). The wide spread among simulation results, especially at M_⋆ ≲ 10⁹–10¹⁰ M_⊙, shows that the low-mass end of the BHOF is sensitive to variations between the simulations (e.g., BH seeding, feedback, and dynamics models, numerical resolution, and box size).