The spectral evolution of the first galaxies. I. James Webb Space Telescope detection limits and color criteria for population III galaxies

Understand

The James Webb Space Telescope (JWST) is expected to revolutionize our understanding of the high-redshift Universe, and may be able to test the prediction that the first, chemically pristine (population III) stars formed with very high characteristic masses.

• Since isolated population III stars are likely to be beyond the reach of JWST, small population III galaxies may offer the best prospects of directly probing the properties of metal-free stars.
• Here, we present Yggdrasil, a new spectral synthesis code geared towards the first galaxies.
• Using this model, we explore the JWST imaging detection limits for population III galaxies and investigate to what extent such objects may be identified based on their JWST colours.