Left: modelled X-ray emissivity ε = n² Λ(T,n) after 8000 yr (XMM-Newton density model) simulating the intensity map (0.3−4.0 keV) of CTB 109 from the XMM-Newton EPIC data (Sasaki et al. 2004) (cf. Fig. 1 (right)). Right: modelled X-ray emissivity ε = n² Λ(T,n) after 11 000 yr (Chandra density model) using the same intensity map (0.3−4.0 keV) of CTB 109 from the XMM-Newton EPIC data. The position of the SN explosion is marked with a black star and the position of the AXP with a magenta star.