Spectral parameters derived before (left panels) and after (right panels) clipping for the regions deviating more than 1σ from the azimuthal values. In blue and red we show the results obtained with maps of S/N = 30 and S/N = 50, respectively. In each panel we provide the correlation (i.e., Spearman rank test value r) between the spectral parameter and T, the median value of the distribution μ, and the standard deviation σ.