New o - H₂CO line detected toward the PDR (left) and dense-core (right) positions. The three color lines plot the radiative-transfer models from Guzmán et al. (2011), where the column density was varied around the best match (red curve) by a factor of 1.5 (blue curve) and 1/1.5 (green curve). The column density used for the best fit is given in Table 6. The line frequency in GHz is given in each box.