Intensity of the particle and proton components of the quiescent background in the 2 − 10 keV band for the 33 obsid s of the XMM-CDFS. The obsid s are numbered from 1 to 33 according to observation date; the vertical dotted line marks the separation between the 2001 − 2002 and 2008 − 2010 observations. Filled triangles: PN particle background; empty triangles: PN residual soft protons (after light curve screening; see Sect. 5.3); filled circles: MOS1 particle; empty circles: MOS1 protons. The MOS2 camera has values very similar to the MOS1.