Core-excised X-ray luminosity L_X, ce vs. mass M in the Magneticum simulation colour-coded by gas-fraction (top panel), formation epoch z_f (second panel from the top), concentration c (central panel), richness n (second panel from the bottom), and BCG stellar mass (bottom panel). To illustrate the dependence at fixed mass, we only show data in a small halo mass range (1 − 2 × 10¹⁴ M_⊙).