Spectra of the background region. Spectra of all TMs are shown in different colors. The straight lines represent the particle background. The Gaussians correspond to the SWCX lines and the detector line. The three thermal components consist of the hot halo, cold halo, and local hot bubble. The unresolved background of cosmological sources is fitted with an absorbed power-law model, with a photon index Γ = 1.46.