Averaged E_th evolution of the BS maximum significance for different source composition models. The E_th evolution averaged over 300 datasets (setting ψ to 27°) is shown with a thick red line for the all particles dataset while the light (H+He) and heavier components are shown respectively in blue and green (the shaded areas show the 90% dispersion of the 300 datasets). The brown shaded area shows the 99% dispersion of isotropic datasets. For both panel, the baseline volume-limited catalogue and a 1 nG EGMF are assumed. The left panel shows the case of the source composition model A and the Sun+Planck GMF model with λ_c = 100 pc, and the right panel the case of model B and JF12+Planck model with λ_c = 500 pc.