Top: AlO N = 9−8 spectrum observed with ALMA on 12 July 2015 (red line). This is the best-quality (S/N and spectral resolution) spectrum of this transition to date. It was extracted from a region where profile-integrated flux is above the 3 × rms noise level. Our simulation of the profile is drawn in blue (see text for details). The green vertical bars mark individual hyperfine components with the height of the bars corresponding to the relative line strength, S_i, at V_LSR of 46.9 km s^-1. Bottom: the profiles of the same line in the APEX (magenta) and ALMA data from Feb. and May 2014 (black). Both spectra were smoothed for clarity. The APEX spectrum is scaled in intensity units.