Abstract

The ultraviolet spectral region provides invaluable diagnostics in star-forming galaxies. JWST will break new frontiers with observations at redshifts close to the era of re-ionisation. I discuss some of the relevant open science questions and the requirements for spectral libraries used as templates for comparison. The trade-os between empirical and theoretical libraries are evaluated. I highlight shortcomings in existing libraries, and suggest pathways for moving forward.