2D spectra of the radio galaxy and close-by neighbours (inverse gray scale) corresponding to the two slits in Fig. 1 with position angles of − 55° (top; sources A and B) and −10° (bottom; source D). The vertical lines point to the position of the four detected emission lines (Lyαλ1216, CIV λ1550, HeII λ1640, CIII] λ1909) at the redshift of A. Continua of sources A, B and D are indicated by the horizontal ticks.