IRAM spectra of 86 GHz SiO maser lines. Each panel shows at the bottom the spectrum obtained with the autocorrelator (1.1 km s⁻¹), and at the top that obtained with the filter bank (3.5 km s⁻¹, offset from zero). The line-of-sight velocity listed in Table D.1 is indicated with a small vertical bar at the top of each panel. The conversion factor between antenna temperatures and flux densities is 6.2 Jy K⁻¹.