PV maps of the line-to-continuum emission ratio in eight FELs, obtained from the X-shooter data. All images are shown in log scale and aligned with the blue-shifted lobe toward the bottom of the panel (negative-y direction). Top: [O I] and [S II] lines; [O I]λ5577 primarily traces the LVC while [O I]λ6300 and [S II] trace both the high-velocity jet and LVC. Bottom: far-left panel shows an image of the continuum emission flux. The remaining panels show [O III] and [N II] lines that trace the high-velocity jet only.