Upper panel: electronic spectrum of gas-phase NO from Chang et al. (1993) and electronic spectrum of gas-phase (NO)₂ from Forte & Van Den Bergh (1978, open dots) and its Lorentzian fit (solid line). Middle panel: NO photodesorption spectrum of 10 ML thick NO ice on HOPG at 10 K between 6 and 13.6 eV (filled squares). Large energy steps of 0.3 eV were used to avoid ice ageing. Absorption spectrum of pure solid NO from Lu et al. (2008) between 5 and 11.7 eV (dashed line). The absorption spectrum is scaled to the photodesorption spectrum. Lower panel: CO photodesorption spectrum of a 20 ML thick CO ice on gold at 10 K between 7 and 13.6 eV (Dupuy et al. 2017).