Two-dimensional weighted (considering Geminga’s spectral index Γ = 4.5) histogram of the reconstructed energy versus the true energy, projected onto the true energy axis for the two reconstructed energy bins used for the morphological study of P2, [15, 31] GeV (left) and [31, 65] GeV (right). The Monte Carlo data used for the plots were produced at Zd = 10°. The dashed line represents the equivalence between the true energy E_true and the reconstructed energy E_reco. The z-axis is in units of rate, i.e. events per second.