1D spectrum of z2LAE3 along the entire MMIRS coverage. The black (red) curve represents the raw (smoothed) spectrum. Grey vertical lines indicate the wavelength of the dominant sky emission lines. Cyan curve represents the atmospheric transmission at Las Campanas observatory. At λ ~ 14 000 and ~19 000 Å the transmission is very low. The green curve represents the background spectrum extracted far from the center of the slit where the source is positioned. Sky line residuals produce higher uncertainty. Telluric correction fixes the continuum shape but increases the uncertainty. Wavelength regions of high noise are not shown in the smoothed spectrum.