Spectrum of nucleus A (see Sect. 4). We show only the two most interesting wavelength intervals. Some spectral features are marked for orientation. Upper panel: black solid line marks the observed spectrum, the red solid line the model spectrum. The fluxes are given in units of 10⁻²⁰ erg⁻¹ cm⁻² Å. Lower panel: model spectrum has been subtracted. Here the emission lines are local foreground/background and the cluster itself apparently does not host ionised gas. Right panel: spectral region of the Calcium triplet. This near-infrared region is not well fitted. We therefore measure the EWs directly in the spectrum.