A_V maps determined in three different ways. Paα and Brγ line ratios were used for a) and b). Case B recombination was assumed for narrow and broad components. White space represents either negative extinction or we measured neither Paα nor Brγ flux. c) shows the extinction that was fitted by our routine (see Sect. 3.3). Note that it overlaps with the dustlane that crosses the galaxy from east to west (see Fig. 3). All colorbars have different scales.