Observed line of methanol at 44 069 MHz (7_0,7−6_1,6A⁺ transition) for different values of the total gas pressure. The integration time was 40 min for the narrower feature. The spectral resolution is 180 kHz obtained by a five channel smoothing of the original data. A shift by −0.3 K is introduced in the vertical scale of each spectrum with respect to the previous one, as pressure decreases.