Power spectrum model of the individual maps: Planck (top), WISE (middle) and MegaCam (bottom). The power spectrum is given by the black dots. The global fit is the red curve. The blue points represent the cirrus component (P(k) − B(k) × Ck^β) while the green dots represent the noise component (P(k) − B(k) × Ak^γ). The dashed and dash-dotted curves are the results of the fit for the cirrus and noise terms respectively. The slope of the dust emission power spectrum is γ = −2.7 ± 0.1, γ = −2.9 ± 0.1 and γ = −2.9 ± 0.1 for Planck, WISE and MegaCam, respectively.