(traditional dense gas tracers in blue and additional tracers in green), and
the red dashed lines represent the model results. Each panel row contains all
observed transitions and isotopologs of any given molecular species, except
for the last row that shows together the only observed lines of CN and C3H2.
Several SO and C3H2 points can be seen above the plot lower limit at very low
column densities. A visual inspection of their spectra suggests that they
represent noise or baseline residuals, and not true molecular emission.