(a) WISE three-color image (w1 in blue, w2 in green and w4 in red) highlighting SF sites (marked as A−F) toward the boundary of the SE of HB 3 and the H II region W3 and the southern H₂ filament. The star-forming regions marked as A and B are located at the boundaries between the SNR and the W3 complex, C and D are at the edge/in the H II regions, and E and F are outside the W3 complex, which may be in the dark clouds and associated with SNR feedback. The red and green circles indicate the positions of Class I and Class II YSOs, respectively. Class I YSOs tend to locate in dark clouds where they are born. The southern inner (the upper box) and outer (the lower box) shell regions are marked as a box (see also Figure 5.) (b) YSOs of Class I (in magenta) and Class II (in green) are marked on the AKARI 160 μm image. Class I YSOs are located along the long filaments or clumps of bright emission of 160 μm map.