Total integrated spectra for the northern (dark blue) and southern (black) nuclei of NGC 6240 obtained with a circular aperture of radius 0.7″. The top panel shows the full MRS spectral range after scaling the flux of some individual bands to match between them. The middle and bottom panels show the spectra per channel, with the main ionised gas emission lines indicated in blue, the H₂ rotational lines in yellow, and the recombination H I lines in green. The wavelength is in rest frame assuming a redshift of 0.02448 (see Sect. 2). We applied a residual fringe correction for the 1D extracted spectra in ch3 and ch4 (see Argyriou et al. 2023).