Maps of the mean emission in various molecular lines. For the sake of direct comparison with the line maps we show again the map of the continuum emission in the bottom right panel. For each map, the values of the contour levels are marked in the corresponding color scale. The crosses and letters indicate the positions of the six cores identified by us (see also Fig. 5). Cores A1, B, and E correspond to the crosses in Fig. 2. The ellipse in the bottom right of each panel is the synthesized beam.