Average emission lines detected toward the various regions delineated in Fig. 8. The line profiles and strength between the Class 0 core and the rest of the regions are significantly different. The Rim S region also appears to be denserthan the rest, although it is clearly less dense than observed toward the Class 0 source. High-density tracers (N₂ H⁺ and DCO⁺) are only observed toward the densest regions. The CN line (which is presented here multiplied by a factor of 3 because it is relatively weak) is strongly associated with the edges of the cloud, as expected if it is dominated by the photoevaporating cloud interface.