APS (in Jy² sr⁻¹) as a function of spatial frequency k (in arcmin⁻¹) for the three observed frequencies (from left to right): 305, 253, and 237 GHz. This is shown (from top to bottom) for each component separately: all the interlopers (CO+[C_I]), the bright interlopers (i.e. above the mass threshold), the faint interlopers, and [C_II]. The intrinsic power spectra of each (unmasked) component are shown with solid black lines, and with a solid green line for [C_II]. The power spectra obtained from the maps that are masked using r_σ = 1.5–3.0 are shown with coloured points (from blue to yellow, respectively).