# Challenges in modelling the rest-frame ultraviolet/optical spectra of galaxies at the high-redshift frontier

## TL;DR

Upcoming telescopes like JWST will push the boundaries of high-redshift galaxy observations, revealing new challenges in spectral modelling related to stellar populations, Population III signatures, and ionizing radiation leakage.

## Contribution

This paper identifies and discusses three key modelling challenges that will become critical for interpreting future high-redshift galaxy spectra.

## Key findings

- Stellar initial mass function sampling effects are significant at faint flux levels.
- Population III signatures may be detectable in upcoming spectra.
- Ionizing radiation leakage impacts the interpretation of galaxy spectra.

## Abstract

New challenges in the modelling of galaxy spectra are bound to emerge as upcoming telescopes like the James Webb Space Telescope will allow us to detect galaxies at fainter flux levels and higher redshifts than ever before. Here, we highlight three modelling problems that may become relevant for upcoming observations in the rest-frame ultraviolet/optical at the high-redshift frontier: stellar initial mass function sampling effects, Population III signatures and the leakage of ionizing radiation into the intergalactic medium.