X-ray spectrum, using the PN camera, extracted from the sub-region of HESS J1731−347 shown in Fig. 5 (right). The non-thermal emission from the SNR is described by an absorbed power-law model (dashed line). The local astrophysical background, fitted to an off region outside the SNR, is modeled by two components (dotted lines). The low energy component is an APEC model (astrophysical plasma emission code, see http://hea-www.harvard.edu/APEC) representing the background from the Local Bubble and the high-energy component is an absorbed power-law representing the hard X-ray background (unresolved AGNs, cataclysmic variables, etc.). The residuals of the total model (SNR+local astrophysical background) are shown in the lower panel and the χ²/n d.o.f. is 1921/1569.