Symbols (from top to bottom): peak intensity, collisional linewidth and integrated intensity derived from Voigt fits to the observed methanol line (7_0,7−6_1,6, A⁺); data from Fig. 9. In all fits the Gaussian width was fixed to the calculated value. Solid lines (from top to bottom): calculated peak intensity with the calculated broadening coefficient, and intensity, best fit of the collisional widths vs. pressure (the slope yields a broadening coefficient Δν_C = 13.2 ± 0.6 MHz/mbar) and best fit of the integrated line intensity vs. pressure.