JvM-corrected [C II] spectrum of CRISTAL-05 extracted within a circular aperture with a radius of 1.5″ and centered in the [C II] observed frequency ν_obs = 292.48 GHz. We display the continuum-subtracted spectrum from the JvM-corrected data cube with a channel resolution of 10 km s⁻¹ (solid black lines in both panels). (a) Top: 1D Gaussian fitting (solid green line) and the residuals (black dots). (b) Spectrum fit with two Gaussian components (solid red line). As in the panel above, the residuals are plotted as black dots.