Top: the JWST/NIRSpec PRISM spectrum of 3I in the vicinity of the CH₄ ν₃ fluorescence band (black points). The shaded region denotes the wavelength range that includes the detected emission bands, which was masked prior to continuum fitting. The blue curve is the cubic spline fit to the continuum points. Bottom: the continuum-subtracted spectrum (black points), with the best-fit PSG model overplotted. The gray curve corresponds to the full model, with the individual contributions from CH₄ and CH₃OH plotted in magenta and green, respectively.