5.8−13.6 eV ISRF normalized to the Habing (1968) unit as a function of R in the ISM regions for the 0.02 Z_⊙/full and 0.2 Z_⊙/full galaxies. The solid curves are the stacked results from 300 Myr to 1000 Myr, while the translucent curves are the results of individual snapshots with a spacing of 20 Myr. The dotted curves present the stacked results of the corresponding low-resolution galaxies. The grey dashed line shows the value of the background FUV field of G_0, UVB = 0.00 324.