PACS 100 μm image (in units of mJy/arcsec²) of IRC +10216 after subtraction of the smooth halo of the circumstellar envelope. The field-of-view is 975′′  ×  660′′. North is at the top, east is to the left. The pixel size is 1′′. The central target is marked by the innermost white circle. The six radial spikes indicated by the white sectors are due to the support spider structure of the secondary mirror; these regions are not taken into account in the analysis. The position angles of each sector used in the analysis are listed in Table 1.