Multi-wavelength SED of the Kes 73-MC interaction region (‘bright region’ in Fig. 4) in a pure leptonic (left) and lepto-hadronic scenario (right). The model parameters are listed in Table 3. Blue, yellow, and green lines indicate the synchrotron, IC, and bremsstrahlung emission contribution from the same electron distribution, respectively. The red line indicates the proton-proton emission from CR protons.