Spatial distribution of the IR luminosity, for the “standard model”, at resolution R4 (54 pc). The color image represents the IR luminosity map. The color scale is logarithmic. The white contours show the main CO concentrations from the Nanten map (Fukui et al. 2008). This contour level is chosen so that 90% of the CO mass has a higher column density than this level. In other words, 90% of the CO mass is in these concentrations. The map is almost rigorously identical with the “AC model”.