Ideal SEDs for subhalo 0, 31, and 253 881 output by SKIRT. For comparison, NoMedium and ExtinctionOnly mode are employed to generate the optical SEDs, while the NIR ones are generated using DustEmission and ExtinctionOnly mode. The relative deviations in optical and NIR are displayed in the lower panel, where N, E, and D represent NoMedium, ExtinctionOnly, and DustEmission. The optical depth at 5500Å τ_5500Å are calculated and shown in each panel. The viewing angles of subhalo 0 and 31 are both at 0° and 0° for inclination and azimuth, while subhalo 253881 is in two views, face-on and edge-on, indicated in solid and dashed lines respectively. For subhalo 31, we also highlight several emission lines, Hα 6563, [SIII]λλ 9069, 9532, and Paγ 10 941 from left to right. These lines are generated by star-forming regions represented by MAPPINGS-III SED family.