Upper panels: Maps of the distortion of the polarised intensity ΔP/P (left) and the spectral rotation of the angles Δψ_ν (right) for the d12 model. Bottom panels: Relation between the moments value in every pixel and the the two quantities presented in the upper panels. Δψ_ν is defined as the difference of the polarisation angle in each pixel between the d12 emission at 100 and at 353 GHz. ΔP/P is defined as $(P_{\text{d12}}-\overline{P})/P_{\text{d12}}$, where P_d12 is the polarised intensity ($P=\sqrt{Q^2+U^2}$) of the original d12 model, while $\overline{P}$ the one of the pivot modified blackbody of the expansion.