RMS fluctuations (in μK_RJ) of the diffuse components: the “high-frequency Galactic component”, in blue; the “low-frequency Galactic component”, in green, and the CMB in red, as obtained by the Commander algorithm (Sect. 8.2.1). The maps have been smoothed to 35′ resolution. The RMS is calculated at high galactic latitudes, outside two masks covering 23% and 42% of the sky around the galactic plane. Point sources in the PCCS at 30 and 353 GHz have also been masked. An uncertainty envelope is indicated, estimated from the difference of the half-ring-based foreground maps. For reference, the average RMS level in the plane (i.e., using the complement of these masks) is 20 × higher. The grey shaded areas represent the frequency coverage of the Planck bands, based on equivalent-noise bandwidths.