Average intensities of HCN, HNC, and HCO⁺ as function of N₂H⁺ intensity (left) as well as average ¹²CO line ratios of HCN, HNC, and HCO⁺ (right) as function of the N₂H⁺/CO line ratio emission. We do not apply any masking, but utilize all pixels in the FoV. We show the binned intensities and binned line ratios for the total FoV (top) as well as for individual environments (Fig. 1). We provide lines of constant slopes in log space for visual guidance (dashed black lines). The bins cover a range between three times the average N₂H⁺ (N₂H⁺/CO) uncertainty up to the maximum N₂H⁺ intensity (N₂H⁺/CO line ratio).