Best matching solutions for the three events that we have detected and were also spectrally analysed by Risaliti et al. (2011), chosen so as to maximise the agreement with R11 results for N_HX and C_F values as reported in their paper. Blue points indicate a solution with N_HX = 10²³ cm⁻², whereas red ones refer to cases in which N_HX = 2 × 10²³ cm⁻²; circular dots show central geometry solutions (f_d = 0) and triangles indicate a case with impact parameter of the occultation f_d = 2.