Left panel: zoomed view (22″ × 22″/6 kpc × 6 kpc) of the Hα narrow band image from the top panel of Fig. 1 with N_HI contours from the VLA B-configuration 21 cm observations (N_HI = {5, 10, 20, 30, 40}×10²⁰ cm⁻², rose lines); these contours are also shown in Fig. 1 as subdued white lines. The cyclic colour map encodes Hα flux in a asinh-scale from 0 to 10⁻¹⁷ erg s⁻¹ cm⁻² to 10⁻¹⁵ erg s⁻¹ cm⁻². In the brightest central region the archival HST F550M image is inset, with an arbitrary asinh-scaling to highlight the compact super-star clusters that comprise the main stellar body of this system. The violet dashed square indicates the region that is displayed in the right panel. Right panel: inner high-SB_Hα region as seen in the archival HST FR656N image (13″ × 13″/3.5 kpc × 3.5 kpc) displayed here with a cyclic asinh-scale from 0 to 5 × 10⁻¹⁵ erg s⁻¹ cm⁻² to 10¹³ erg s⁻¹ cm⁻². Here the violet dashed square indicates the region that is displayed in Fig. 5.