Large-scale HST images (~45′′× 45′′) taken through filters F502N ([O III] λ 5007), F631N ([OI] λ 6300) during the 2013 observing run and the filters F656N (Hα) and F658N ([NII] λ 6583) obtained in 2014. The colour scale for the fluxes ranges from 0 to 10⁻¹⁶ erg cm⁻² s⁻¹ Å⁻¹. The Hα map contains a roundish emission spot (~2–3′′ to the west of the central source) which is probably an “image ghost” (see also Fig. 2).