SPL fit (green region), BPL fit (magenta region) and GDPL fit (red region) of the IllustrisTNG haloes (median of the data in black solid line), to the scaling relation of the mass fraction of baryons f_bar and halo mass M in a radius R_500c. Each panel is labelled with the corresponding simulation tag in addition to a vertical dark green dashed line that represents the M_pivot of the broken fits. The power values of α_SPL SPL fits, α_BPL,1 and α_BPL,2 BLP fits, and α_GDPL,1 and α_GDPL,2 GDPL fits, with the GDPL smoothness parameter δ and M_pivot value are in the Table 5. Top panels: fraction of baryons includes the hot-gas and the $2\times R_{M_{\mathrm{star}}/2}\sim r_{\mathrm{op}}$ aperture. Bottom panels: baryon fraction includes all gas and stellar mass within each halo. The yellow region represent the Planck Collaboration XIII (2016) fraction of baryons. All the regions are in 3σ.