Value of reflectance at 0.72 μm (left panel) and spectral slopes (right panel) of the Fig. 7 ratios: virgin sample over irradiated sample. The orange dots are for irradiations with He⁺ ions, purple is used for Ar⁺ ions. The spectral slope is calculated using a linear fit on the whole range (0.44-1.0 μm, dots) when available or on a restricted area (0.72-1.0 μm, + signs) otherwise. The gray error bar in each panel indicates the variations due to our Murchison sample heterogeneity.