(Left) ¹²CO(2−1) emission integrated between  −21 and  −17 km s^-1, showing the molecular “ring”. Contour values are from 10 to 80 K km s^-1 in steps of 10 K km s^-1 (the three highest levels are drawn in white). The three most massive clumps defining the “ring” are marked with numbers 1 − 3; the prominent CO-peak in the SE-cloud is marked with number 4, and minor condensations in the “ring” with 5 and 6. These, as well as “jet” and “star” mark positions towards which we searched for H₂O maser emission (see text). (Right) Overlay of and optical image. The CO-emission is integrated between  − 23 and  − 15 km s^-1. Contour values [lowest(step)highest] are 10(10)40 K km s^-1 (white), 50(10)110 K km s^-1 (green). In both panels offset (0, 0) as in Fig. 3.