TeV spectra resulting from hadronic CR-gas interactions, from CRs trapped inside the downstream of shock region of SNR HESS J1731-347 (solid lines) and from CRs interacting with MC-J1729 (dashed lines). Red/green lines represent the 20 M_⊙ in-shell and 25 M_⊙ in-shell scenarios shown in Table 3. Adopting a Galactic standard diffusion coefficient D₁₀ = 10²⁸ cm² s^-1,δ = 0.5 over the entire space, we fitted the spectrum of MC-J1729 (at 30 pc distance from the center of the SNR). Observational data from Abramowski et al. (2011) and Acero et al. (2015) for HESS J1731-347 and HESS J1729-345 are shown as blue stars and black circles, respectively.