Example of a more detailed classification of the surroundings of HMSC. Four types of morphology are shown for AS. The RGB images are constructed in the same methods as in Fig. 1. The solid circles indicate the H II regions. Yellow crosses and blue contours represent the ATLASGAL clumps identified by Csengeri et al. (2014) and the ATLASGAL 870 μm emission, respectively.The white crosses with purple squares indicate the HMSCs.