Spectral energy distribution of the southern structure fitted with leptonic and hadronic models. The left and right panels show the SEDs derived with the southern eB and Loop I spatial templates, respectively. The leptonic scenario (inverse-Compton) assumes a BPL (γ₁ = 1.5) electron distribution. For the hadronic (pp) fits, a PL or ECPL proton distribution is adopted, with target gas densities assumed to be n_H = 1.0 cm⁻³ for the local components and n_H = 10⁻³ cm⁻³ for the Galactic-scale structure toward the GC. Upper limits are shown for reference and are not used in computing the model likelihoods reported in Table 1.