Comparison of an event cube generated with GammaLib for viewing period 2.0 and the 1–3 MeV energy band (red solid) and the equivalent event cube MPE-DRE-5∅6∅7 produced by the COMPASS software (blue dashed). The left panel shows the distribution of χ values, obtained by summing over all ψ and , the middle panel shows the distribution of ψ values, obtained by summing over all χ and , and the right panel shows the distribution of values, obtained by summing over all χ and ψ.