Residual maps for three viewing periods and the 1–3 MeV energy band with background modelled using the BGDLIXE algorithm for N_avgr = 5 and different values of N_incl. The colour scale is limited to the range −5σ (blue) to +5σ (red). Viewing period 1.0 was selected because it contains the Crab, viewing period 223.0 because it has a rather flat residual, and viewing period 518.5 because it is among the viewing periods with the worst residuals.