The γ-ray SED obtained with H.E.S.S. and Fermi–LAT are shown together. In addition, the best-fit γ-ray spectrum from pion decay of inelastically scattered protons is shown as a black solid line. The grey shaded areas highlight the 1 and 3σ confidence regions of the fit. The lower panel shows the residuals of the measurement with respect to the best fit, normalised to the measurements statistical uncertainty. Blue and red data points correspond again to the measurements obtained with Fermi–LAT and H.E.S.S., respectively.