Broad-band spectral energy distribution. Flux points and upper limits measured by H.E.S.S. (red circles), HAWC (squares), LHAASO (diamonds), and Fermi-LAT. The Fermi-LAT points are shown both as published in Zhao et al. (2025) (light triangles) and re-scaled to the H.E.S.S. emission region size (dark triangles). The broad-band spectrum is observed to rise sharply until a peak forms at energies of ≈100 TeV, further extending up to energies of several hundreds of TeV.