Correlation plot between column densities of the CH, and OH molecules, integrated over broad velocity intervals asper Table 3. The red triangles and blue squares represent column density measures from Weselak et al. (2010) and this work, respectively. The black dashed, solid, and dotted-dashed lines indicate N(OH)/N(CH) ratios of 10, one, and 0.1, respectively while the linear regression fit to the data, N(OH) = (3.15 ± 0.49) N(CH) is displayed by the red dotted line.