Left: line profiles of all measured molecular gas tracers extracted at the position of the peak emission of each line, after convolving all data to the angular resolution of ¹³CO(1−0). The CO(2−1) spectrum appears as the gray filled region. Other lines are scaled by the factors indicated in the legend to put them on the same plot. Right: RADEX output showing fits to the observed ratios among these lines. Blue, red and green lines correspond to the observed HCN/¹³CO, HCN(1−0)/CO(2−1), and ¹²CO/¹³CO values. The gray diamond indicates the position on the RADEX [n_H2, T_kin] grid where the χ² is minimal (i.e., the best-fit values). The dashed lines show the 95% confidence level of the χ² fit, which is smaller than the size of the diamond.