Fig. 3.
Distribution of YSOs associated with the M 17 SWex region reported by Povich et al. (2016). The contours denote the N2H+ integrated intensity map same as in figure 2 (b). Stage 0/I is the YSO accompanied by an infalling envelope, Stage II is the YSO with an optically thick circumstellar disk, and Stage III is the YSO with an optically thin disk (see Povich & Whitney 2010). (Color online)
