Average diffuse γ-ray flux from DM annihilation in the Galaxy as function of the angle between the observational and Galactic Centre direction ψ. The fluxes from the host halo (double-dot-dashed magenta line), FHM (dashed blue line), and SHM subhaloes (solid red line) are depicted. Each curve was derived at the peak energy of νI_ν(E) (40 GeV) assuming total annihilation in τ⁺τ⁻ with m_χ = 150   GeV and  ⟨ σv ⟩ _eff =  ⟨ σv ⟩ ₀. The minimum subhalo mass used was M_min = 10^-6   M_⊙ (see Appendix C). The EGB at 40 GeV is shown by the dotted black line.