Left panels: [O III] images smoothed with a Gaussian kernel of 0.5″ covering the whole extent of the ionized gas nebula, 120 × 110 kpc, (top panel) and (bottom panel) zooming onto the central 33 × 33 kpc. Center panels: velocity field derived from the same line. Right panels: gas ionization map obtained from the ratio of the [O III] and [N II] lines. The plus symbols indicate the location of N1 and N2.