(a) Dust temperature as a function of the C¹⁸O rotational temperature. The gray error bars represent the measured uncertainties in the measured dust temperature and rotational temperature. The markers’ colors correspond to their H₂ column densities indicated by the color bar. The Pearson correlation coefficient is shown in the lower left. (b) C¹⁸O rotational temperature as a function of the H₂ column density. The gray error bars represent the measured uncertainties in the measured rotational temperature and H₂ column density. The markers’ colors correspond to their dust temperatures indicated by the color bar. The Pearson correlation coefficient is shown in the lower right. In both panels, the black dashed line represents the linear fit to the observed trend.