with a single slab model. Being the most sensitive one among the four parameters that determine the model FUV intensity level, it was constrained very well. We also set the value of the phase function asymmetry factor to be 0.45. The range of *g* was found to be rather broad, implying that the model was not affected significantly by the change of *g*. Furthermore, Figure \[fig:contour\](d) and Figure \[fig:contour\](f), in which the 90 $\%$ contours of the distance and thickness were plotted against *g*, do not show any correlation with the value of *g*. With these fixed albedo and *g*-factor values, we carried out simulations for the sub-regions 1 to 9 individually to obtain the best fitting parameters of the distance and thickness for each of the sub-regions.

![(a) A mosaic FUV continuum map obtained from dust scattering simulations, with the distance and thickness of the sub-regions varied individually, and (b) a pixel-to-pixel scatter plot of the FUV intensities taken from the observed and simulated maps in Figure \[fig:fims\](a) and Figure \[fig:simul2\](a), respectively.\[fig:simul2\]](f4a.eps "fig:"){width="7.3cm"}\
![(a) A mosaic FUV continuum map obtained from dust scattering simulations, with the distance and thickness of the sub-regions varied individually, and (b) a pixel-to-pixel scatter 