Profiles of the inversion lines as computed for the best-fit models, which assume R_ph = 3 × 10¹⁶ cm and the T_gas distribution from Crosas & Menten (1997), (blue dotted lines) are overplotted on the observed inversion transitions (solid lines) from Gong et al. (2015). Theoretical profiles for the same T_gas profile, but with the photodissociation radius reduced to R_ph = 1.5 × 10¹⁶ cm are shown with red dashed lines. Vertical sticks show positions and relative intensities of hyperfine components.