MAP2 molecular lines are shown in the upper panel. To increase the S/N, all spectra of the same species were averaged. The ¹³CO traces predominantly denser gas, so present a narrower linewidth respect to diffuse gas tracers. MAPZ molecular lines are shown in the lower panel. There is only one CH spectrum near MAPZ (position 11 in Fig. 1) but it shows a very low S/N, so we did not plot it here. All line intensities are normalized to ¹²CO peak antenna temperature, except for ¹³CO, which is shown without any rescaling.