Left panel: photon index map along the main jet and PWN. The colours represent different spectral indices, as shown in the colourbar at the bottom of the plot. Contours are drawn around the regions for clarity at levels of Γ = 1.1,1.5,1.8,2.8. Typical uncertainties on the spectral indices are of the order of ± 0.1. Right panel: the same contours are reported on the spatial map to aid the visual identification of the regions used for the spectral extractions and of the regions clustering around similar values of Γ. The region in red was used to extract spectra from the main jet.