Spectra and irradiation maps of the ices explored in this work, all taken at 20 K. Panel a: pure amorphous CH₃OH. Panel b: pure amorphous and crystalline CO. Panel c: mixture of CH₃OH and CO with a CO:CH₃OH ratio of 1:0.3. Panel d: same as panel c, but with a 1:3.0 ratio. All spectra are taken after deposition and before irradiation. The wavelengths of FELIX-2 used later for on and off-resonance irradiation are shown with dashed lines, and the FWHM is visible from the shadowed areas. The fundamental mode of CO is denoted in boldface, and the other labels correspond to the (v_X) vibrational modes of CH₃OH.