Top: spatial profile of the emission along the UVES slit (see Fig. 1) for [O III] λ5007, created from the F502N filter of ACS. Bottom: combined spatial profile of the Hα and the [N II] λλ 6548, 6583 doublet created from the F658N filter of ACS (2003 January 5). In both plots the SOR is shown to the left and the NOR to the right. The cusp-like feature discussed in Fig. 1 is clearly seen as a broader outer-ring feature from the NOR than from the SOR. The spike at to the north is a star.