The total (full + partial) event rate density in the ﹩\mathrm{log}{M}_{{\rm{BH}}}\times \mathrm{log}{L}_{{\rm{peak}}}﹩ plane for flux-limited samples. Both plots have α_BH = 0, but the one in the left panel utilizes a Salpeter IMF mass function, cut off at 1 M_⊙, i.e., α₁ = 2.35, α₂ = 4, and M_b = 1 M_⊙, whereas the one in the right panel has no cutoff: α₁ = α₂ = 2.35. Rates (arbitrary units) are shown on a linear scale calibrated by the color bar.