Synthetic spectra (λ∕Δλ = 50) of the DRIFT-PHOENIX atmospheric models that best describe the photometry of β Pic b with a prior on its mass. The two colored lines show the interpolated spectra for the median values of the posterior distributions, except for the metallicity, which is set to [Fe∕H] = -0.06 (red) and [Fe∕H] = 0.0 (teal). Additionally, 30 sets of parameter values were randomly drawn from the posterior distributions (see Fig. 10) and shown as gray spectra. The black solid squares are the data and the black open squares are the synthetic photometry for the best-fit model. The differences between the data and the synthetic photometry are shown in multiples of the 1σ uncertainties. The horizontal error bars indicate the FWHM of the filter transmission profiles, which are also plotted above the spectra. The mass and luminosity in the legend have been computed from the fit results.