varied from 10 pc to 200 pc with 10 pc steps, the albedo varied from 0.35 to 0.50 with 0.01 steps, and the g-factor varied from 0.20 to 0.70 with 0.05 steps. For each simulation, 10$^8$ photons in total were randomly generated from the point sources. Each simulation result was compared with the FIMS observation to obtain the best fitting parameters using the chi-square minimization method.

Figure \[fig:simul\](a) shows the simulated FUV map for the best fitting parameters: 80 pc for the distance to the front face of the dust slab, 70 pc for the thickness of the slab, 0.43 for the albedo, and 0.45 for the *g*-factor. Figure \[fig:simul\](b) is a scatter plot obtained from a pixel-to-pixel comparison between the FIMS map of Figure \[fig:fims\](a) and the simulation map of Figure \[fig:simul\](a). We have divided Figure \[fig:simul\](a) into nine sub-regions with a 10$^\circ$ $\times$ 10$^\circ$ area and numbered the sub-regions from 1 to 9, so that the data points in Figure \[fig:simul\](b) were color-coded according to the sub-regions. It can be seen in Figure \[fig:simul\](b) that the simulated intensity generally agrees with the observed one. The reduced chi-square value is $\chi^2$ $\sim$ 5.44. A little lower simulated intensity than 