Upper panel: X-ray energy spectra of the central region of G78.2+2.1 as observed by MOS1/2 (see Figure 1) and PN (see Figure 2), which are simultaneously fitted to an absorbed non-equilibrium ionization plasma model. Additional PL components have been applied to account for the residual soft proton contamination in the individual camera. Lower panel: contributions to the χ2 fit statistic.