Total X-ray luminosity as a function of halo mass (M_500c) (a) within R_500c of each galaxy, (b) within (0.15 − 1) R_500c. Grey dots represent all galaxies in our full sample, including the AGN systems, with BCG galaxies marked as black triangles. Thin and thick lines represent the mean and median luminosity of our sample, respectively. The contribution from HMXBs and LMXBs in our sample is shown in orange and green together with the 16–84 percentile range as the shaded area. Additionally, we show data from Anderson et al. (2015) (cyan squares) for the total X-ray luminosity within R₅₀₀ in (a) and CGM luminosity within 0.15 − 1 R₅₀₀ in (b). The sample consists of central galaxies and results from a stacking analysis using ROSAT data. Their total mass is derived from forward modeling of the L_X − M_500c relation of gas-dominated halos in their sample. The magenta dash-dotted line is the best fit L_X − M_500c relation for stacked galaxies in eRASS:4 from Zhang et al. (2024b). The red dashed line shows the bias-corrected best fit L_X − M_500c relation from Lovisari et al. (2015).