Mean 𝒮 as a function of p in selected regions in the Gould Belt for the Planck data (top) and for our phenomenological model (bottom, see text), at a resolution of 40′. The black curve indicates the mean trend averaged over all regions. The dashed line is the fit to the mean 𝒮 = f(p) trend at 160′ (Fig. 10), corrected for its dependence on the resolution, as per Eq. (10). All bins in p contain the same number of pixels, n ≈ 250. Error bars correspond to the uncertainty on the mean, i.e., , where σ is the statistical dispersion in the corresponding bin.