The high-redshift Universe with Spitzer

Maruša Bradač

Published 2020-05-14Version 1

When did galaxies start forming stars? What is the role of distant galaxies in galaxy formation models and the epoch of reionization? What are the conditions in typical star-forming galaxies at redshifts >~4? Why is galaxy evolution dependent on environment? The Spitzer Space Telescope has been a crucial tool for addressing these questions. Accurate knowledge of stellar masses, ages and star formation rates requires measuring rest-frame optical (and ultraviolet) light, which only Spitzer can probe at high redshifts for a sufficiently large sample of typical galaxies. Many of these science goals are the main science drivers for the James Webb Space Telescope, and Spitzer afforded us their first exploration.