Sample two-dimensional spectra of emission along the slit. Three emission lines are shown: Hβ with contours at [3, 5, 10, 15]× σ noise levels; [O III] 500.7 with countours at [3, 5, 25, 50, 100, 200] × σ; and [N II] 658.3 with contours at [3, 15, 25, 50, 100, 200, 400] × σ. Lower right panel: same map of [N II] (gray color scale) where we roughly deliminated with color shaded areas regions A, B, and C defined in the text. The dashed lines indicate the location of the three extracted spectra discussed in the text.