Surface brightness distribution for a stellar distance of 7.7 pc at the wavelength 21 µm (Q band) of the system with belt parameter set n and the inner perturber i-M4 (n-i-M4). The contour lines denote the isophotes of the corresponding 1300 µm map of the same system with a flux density level of 1 % of its maximum value. They enclose the position of the parent planetesimal belt. General figure characteristics are the same as in Fig. 9.