Distribution of the mean CO emission integrated in the velocity range from −7.2 km s^-1 to −3.2 km s^-1. The beam size of the CO observations is shown by a white circle in the lower left corner of each image. The position of WR 16 is marked by a plus sign at the center of each image. a) Emission distribution of the ¹³CO J = 1 → 0. The lowest temperature contour is 0.16 K (~5 rms). The contour-spacing temperature is 0.08 K till 0.48 K, and here onwards the contour spacing is 0.35 K. b) Emission distribution of the CO J = 1 → 0. The lowest temperature contour is 0.8 K (~10 rms) and the contour-spacing temperature is 0.7 K. c) Overlay of the mean CO emission in the velocity range from −7.2 km s^-1 to −3.2 km s^-1 (contours) and the Hα emission (gray scale) in the central region. Contour levels are the same as in Fig. 2b.