Spatial distribution of the 22 protoplanetary disks categorized in Section 4.1. The red dots are sources of type I. The green squares correspond to type II sources. The blue crosses are the type III sources. The dark triangles are ambiguous. The position of θ¹ Ori C and θ¹ Ori A are marked with the purple stars. 244–440 and 203–504, which are illuminated by θ¹ Ori A, are not in this subsample.