Overlays of selected pairs of emission tracers as described above each panel. The integration ranges for the atomic and molecular lines are the same as in Fig. 2. The contour levels are chosen individually for each figure to highlight the emission best. The angular resolution elements for both tracers are presented in the top-right of each panel. The five-pointed stars always mark the position of the embedded source NGC 7538IRS1 and the two open stars show the positions of the two main exciting sources of the H II region NGC 7538IRS5 and NGC 7538IRS6. A linear scale bar is presented in the bottom-left panel.