Fig. 1.
Distribution of the amplitude of the bump Eb and slope of the attenuation curve δ as defined in Eq. (1) and (2). Both parameters are determined with the CIGALE code which does not only give the best model fitted (based on a χ2 minimization over all the models) but also calculates the probability of each input model and returns the probability distribution function (PDF) of each parameter. The histograms with spikes correspond to the values found for the best models and the continuous lines represent the distributions of the mean values of the PDF of Eb and δ obtained for each object. The values corresponding to the attenuation curve of Calzetti et al. (2000), (C00), of the extinction curves of the Milky Way (MW), LMC2 supershell (LMC2) and of the SMC (SMC) are plotted as dotted lines. The parameters for the MW are taken from Fitzpatrick and Massa (1990), those for the Magellanic Clouds come from Gordon et al. (2003).