Notes. Column (2): flux density above which sources are detected in the simulation, i.e. confusion limit defined as the depth above which 68% of the sources get measured with a photometric accuracy better than 32%. Column (3): A_beam is the beam area at the central wavelength listed in Col. (1) defined as π× (0.73 × FWHM)² (Dole et al. 2003; Oliver et al. 2010). Column (4): N_compl is the completeness in % in number of clean sources (neib24 ≤ 1), i.e. the % of sources injected with Sⁱⁿ ≥ S_lim that are detected in the simulation as clean and with S^out ≥ S_lim. Column (5): IGL_compl is the completeness in % in contribution to the IGL. Column (6): N_real is the number of clean sources detected in the real Herschel maps above S_lim. Column (7): beams/source is the number of beams per source, where N_beams = 150^′2/A_beam.