Abstract

I will talk about comparing our new rest-frame UV and optical emission line diagnostics for star-forming galaxies. We apply these diagnostics, for the first time, to the brightest known lensed galaxy at cosmic noon. We infer nebular properties including the metallicity, ionization parameter, electron temperature and ISM pressure. The combination of diagnostics allows us to probe different ionization zones within the nebula. Our study demonstrates the power of rest-frame UV spectroscopic surveys when combined with these diagnostics and unprecedented sensitivity in the JWST and ELT era. However, the spatial resolution of these surveys might impact the accuracy of measuring the distribution of metals in galaxies. We produce a suite of synthetic IFU data cubes from simulations, to quantify the said effect of spatial resolution.