Broadband SED from radio to γ rays for Kes 17. The fluxes in the radio band correspond to those in Table 1 (in units of erg cm⁻² s⁻¹), while those at γ-ray energies correspond to the new Fermi-LAT data from this work (Sect. 4.2). The upper limits at X-ray and TeV energies where derived from the non-detection of X-ray synchrotron emission and the H.E.S.S. observatory, respectively (see text for details). (a) SED modelling with a unique electron population producing synchrotron and IC radiation over the broadband spectrum. (b) SED modelling with an ExpCut-off proton-dominated model producing synchrotron, IC, and Bremsstrahlung radiation from a parent electron population, and γ-ray emission via the decay of π⁰ created from a proton population interacting with the surrounding gas (see Table 2 for a complete list of parameters).