Example of the LIME fitting process on the Hα + [NII] doublet of ID 6563 (z ∼ 1.7). The top figure shows the Gaussian profile fittings while the lower figure shows the residual between the observation and the theoretical fits. The red shade in the bottom plot shows the calibration pixel error while the yellow shade shows the standard deviation from the continua bands. The gap between the red and yellow regions is intended to avoid potential contamination of uncertain line wings and artefacts.