Images for the individual emission components. From left to right: the single-scattering component (I_a); thermal emission from the surface layer (I_c) and the disk interior (I_d); and the intensity ratio for the thermal emission (I_c+I_d) per the single scattering emission for FU Ori at λ =12 μm, assuming that the extended emission is associated with a disk, and . A combination of a star as the central illuminating source and the ‘Dust1’ model are used.