Stellar (blue stars), gas (magenta squares), and total baryon (black triangles) mass fractions as a function of total mass for r₂₅₀₀ (top panel) and r₅₀₀ (lower panel). The solid lines correspond to the best linear fit for each relation. The two blue dashed lines correspond to the fits for the groups and clusters separately. On the bottom of each panel, we show the ratio between the total baryon fraction determined by the sum of f_star and f_gas and the WMAP-7 value as a function of total mass.