Map of the continuum in a region centred at the ‘haze’ highlighting a bright disc galaxy at z = 2, the haze itself, and a region south-west of GN-z11. The spectra of these three regions are shown in the right panels, highlighting the wavelength of our HeII detection, as well as other detected emission lines. The galaxy at z = 2 does not have any bright feature at wavelengths close to 1.902 μm. The haze presents a single emission line that we tentatively identify as [OIII]λ5007 at z = 3.66 – which would be consistent with the photometric redshift from Tacchella et al. (2023). Finally, we detected an emission line in the SW lobe of GN-z11. At the redshift of GN-z11, this line would correspond to a rest-frame wavelength of 0.1684 μm – which we do not trace to any notable emission line.