Multi-wavelength fit of XMM-Newton and HESS data using a one-zone electron synchrotron model. Left: likelihood profiles for the average magnetic field inside the 0.06°-radius HESS J1702−420A region, assuming a one-zone leptonic model, for different values of assumed absorption column density (n_h) and electron cutoff energy (). Right: synchrotron and inverse-Compton spectra corresponding to the 3σ (red), 2σ (green), and 1σ (blue) magnetic field upper limits in the HESS J1702−420A region, together with the best-fit inverse-Compton model for the HESS SED (black). For this illustrative plot, a n_h = 5 × 10²² cm⁻², and minimum electron energy of 100 GeV were assumed. An electron spectral index of Γ_e = 1.48 ± 0.27, obtained from a fit of the HESS data points alone, was also assumed.