Spectral energy distributions of the 12 sources constrained by the observations presented in this work. The orange butterfly represents the Fermi-LAT measurement (from the 4FGL), and the cyan one indicates the extrapolation towards the energies observable by H.E.S.S. including EBL absorption. The black line represents the observed H.E.S.S. upper limit at 95% CL assuming an index of 3.