Rotational diagrams of SO, SO₂, OCS, H₂CO, D₂CO, H₂CCO, c-C₃H₂, CH₃OH, CH₃CN, CH₃CCH, and CH₃CHO. The parameters N_up, g_up, and E_up are respectively the column density, the degeneracy, and the energy (with respect to the ground state of each symmetry) of the upper level. The derived values of the rotational temperature and the column density are reported in each panel for each species. For D₂CO the blue and red circles indicate ortho and para transitions, respectively. For CH₃OH the blue and red circles indicate E and A transitions, respectively. Red stars in the c-C₃H₂ (8_3,6 – 8_2,7) and CH₃OH (10_2,9 – 9_3,6) indicate transitions not used in the fit, due to contamination by other molecules. The blue arrow in the CH₃CN panel indicates 12₄ – 11₄ transition, which was not used in the fit as upper limit. The error bars include the errors on the flux, as stated in Table A.4, and the uncertainty of the calibration of 20%.