Notes. HCO, H¹³ CO, and SiO (see Table 1 and Fig. 6) are severely blended and therefore excluded from the list. Our remaining seven molecular lines are presented on top, following increasing frequency. For most transitions, integrated intensities (I_mol; Col. 9) provide the difference between emission and absorption. Only CH₃ C₂H appears to be entirely free of absorption. Formal accuracies of the peak positions in Cols. 4 and 5 are ± 0.′′4, ± 0.′′1, ± 0.′′2, ± 0.′′4, ± 0.′′3, ± 0.′′5, and ± 0.′′5 from top to bottom for our ALMA data with ≈2″ resolution (see Col. 2). Numbers in parentheses indicate standard deviations of the two-dimensional Gaussian fits to the original (not beam deconvolved data) and do not include the 10% calibration uncertainty given in Sect. 2. For comparison, we also included parameters from the HNC and HCO⁺ data of Cunningham & Whiteoak (2005), from our λ ≈ 3 mm continuum data (see Sect. 3.1), and from the 22 GHz (λ ≈ 1.3 cm) H₂ O megamaser disk discovered by Greenhill et al. (1997). The uncertainty in the Cunningham & Whiteoak (2005) positions is ≈ 0.′′4; that of the megamaser disk is 0.′′1. The uv coverage of the Cunningham & Whiteoak data is limited, leading for example to a position angle of 29° for the continuum. Therefore their PA values are not included and we also do not derive rotating disk inclinations from their data.