Two XMM-Newton EPIC-pn spectra: in blue the astrophysical observation mentioned in Fig. 1; in orange the data taken with the filter wheel of the camera in closed position. The closed observation shows the intrinsic detector background mainly dominating the low-energy domain. The peak observed at higher energy is created by particle radiation entering the detector not via the telescope, but rather from all around the spacecraft. These are raw amplitude spectra (not corrected for charge-transfer efficiency) for an Open observation of N132D from 2009 (revolution: 1681; observation ID: 0414180401; exposure ID: PNS001) and a Closed observation from 2003 (revolution: 621; observation ID: 0150651101; exposure ID: PNS001 in Small Window Mode). The x-axis refers to the pulse height amplitude (PHA), which is the XMM-internal energy measure (in adu), with 1 adu ~5 eV.