Radial profiles extracted from the extinction map of Alves et al. (2001a) (upper panel) and the newly calculated extinction map shown in Fig. 2 (lower panel). The small dots represent the data in the maps after regridding them to the same scale; the large dots are the mean values in bins of 20″ each with the error bars indicating the corresponding rms scatter. The mean distributions follow a profile fit similar to Eq. (15) (solid line). The power-law indices are α = 3.3 in the upper panel and α = 3.1 in the lower panel. For comparison, we added the profile of the BES (dashed line) given by Alves et al. (2001b).