WISE W3 and W4 colour-corrected fluxes of 10-km asteroids vs. heliocentric distance (blue and ochre empty circles). The purple and green lines are the corresponding model fluxes with Γ₀ = 10 J m⁻² s^−1/2 K⁻¹ and α = 0. For reference, since we have excluded partially saturated fluxes from the analysis (cf. Fig. 8, left panel), we also indicate the fluxes at which saturation occurs in each band (Cutri et al. 2012).