Beam normalisation factor (BNF) to reduce observed emission line fluxes from Tables 2, 3, 4 to those enclosed by a 22′′ beam; for line fluxes expressed in   K   km   s^-1, multiply BNF by (θ_b/22)², where θ_b is the observing FWHM beam-size from Tables 2 and 4.

Emission line fluxes normalised to the response of a 22′′ beam by application of the BNF.

Beam-independent absorption line flux derived from the estimated difference between integrated and Gaussian-fitted line intensities in Table 2; adopted error: 50%. Note that this is the total amount of absorption over the whole profile, not just the prominently visible deep absorption at systemic velocities.

Final adopted emission line luminosity in a 22′′ beam, corrected for absorption line losses. For   ¹³CO we did not determine line fluxes, but derived corrected luminosities directly from the more accurate   ¹²CO values using the mean of the   ¹²CO/   ¹³CO ratios in Table 3.