Description
One of the most remarkable outputs from the James Webb Space Telescope (JWST) has been the incredible spectral data covering various UV-optical emission lines in the high-redshift Universe (z>5). Multiple emission lines originating from the nebular regions of these galaxies have been observed, and using calibrations based on line ratios, the community have been able to infer quantities such as the dust attenuation, metallicity, etc of these galaxies. These are calibrations based on photoionisation models, SPS models, or assumptions on the conditions of the Interstellar Medium (ISM) using single-cloud models. In this talk, I will explore the robustness of these relations within a self-consistent framework of galaxy formation and evolution. Using toy models and forward modelled galaxies from the First Light and Reionisation Epoch Simulations (FLARES), I will demonstrate that these calibrations may be less reliable than commonly assumed. Additionally, I will show that the star-dust geometry plays a significant role in shaping these relationships, even for emission lines that are close in wavelength.
