Arp 220 NE cluster, W and E nuclear spectra from the three NIRSpec gratings. The spectra are shown in luminosity as a function of the rest frame wavelength. The vertical blue lines mark the positions of hydrogen transitions (dark to light blue indicate distinct hydrogen series). The orange lines identify H₂ lines, the red lines are associated with [Fe II] transitions, and the green lines mark He I emission features. Strong broad-band absorption and emission features are also labelled in the figure. Zoom-in plots are presented in Appendix B.