Triangle plot showing the 2D (1D on the diagonal) posterior probability distributions for the derived stellar mass (M; accounting for mass returned to the ISM through stellar winds and supernova explosions), star formation rate (ψ), maximum age of the stars (t), effective V-band attenuation optical depth ( = A_V/1.086), ionisation parameter (log₁₀U_S), nebular metallicity (Z_neb), escape fraction of H-ionising photons (f_esc), and ionising photon production efficiency (ξ_ion). The contours in the 2D posterior plots show the 1, 2, and 3σ credible regions in dark, medium, and light blue, respectively. The inset shows the resulting fit to the prism spectrum, with the spectrum and 1σ standard errors shown as the red line and shaded region, respectively, and the 1σ range of fitted model spectra in blue. Regions that are masked in the spectrum are shown as fainter red (data) and fainter blue (model) shaded regions.