The grey-scale shows C¹⁸O(2–1) moment maps: 0th moment or integrated intensity on the left, 1st moment or intensity-weighted velocity in the middle and 2nd moment or intensity-weighted linewidth to the right. The black contours in the left panel show the integrated C¹⁸O(2–1) data and go from 20 to 80% in 20% steps. The dotted contours outline the 875 μm emission at a 3σ level from Fig. 1, and the red contours show additionally the high-intensity 875 μm emission in 15σ steps from 15σ onwards (1σ ≈ 70 mJy beam^-1). In the right panel, the 3-pointed stars in the north and south mark the position of an O-star by Bik et al. (2005) and the center of the southern cluster discussed by Blum et al. (2001). The 5-pointed stars mark the two UCHii regions (Wood & Churchwell 1989).