Outflows identified by H₂O proper motions toward the YSOs W51e2-E (top panel) and W51e2-NW (bottom panel) (Sato et al. 2010). The position (circles) and proper motions (arrows) of water masers are overlaid onto the total intensity (0th moment) map of the (6, 6) inversion transition of NH₃ (same as Fig. 15). Colors denote l.o.s. velocity (color scale on the right-hand side in each panel) and the scale for the proper motion amplitude is given in the bottom right corner of each panel (both in km s^-1). The diverging proper motions identify the origin of the fast outflows, i.e., the protostellar position. The peak of the total intensity map of the most highly excited NH₃ transitions (13, 13) (cyan contours) lies at the origin of the H₂O  maser outflow; we assume that its position pinpoints the high-mass YSOs W51e2-E.