North-eastern part of M 33 in the IRAC 8 μm band (Verley et al. 2007). The upper (small) rectangle shows the region presented in Fig. 2 and the small triangles forming an “X” in and around the rectangle indicate the individual positions of the [C ii] HIFI observations. The large lower rectangle shows the region around BCLMP302 observed with PACS by Mookerjea et al. (2011). The center of M 33 is at the position of the triangle to the lower right of the image of M 33. The giant H ii region NGC 604 can be seen as the very bright region to the left around Dec 30:47 and is marked with a  × .