This illustration shows a galaxy forming only a few hundred million years after the big bang, when gas was a mix of transparent and opaque during the Era of Reionization. Data from NASA’s James Webb Space Telescope show that there is a lot of cold, neutral gas in the neighborhood of these early galaxies – and that the gas may be more dense than anticipated.
Webb observed these galaxies as part of its Cosmic Evolution Early Release Science (CEERS) Survey a few months after it began taking observations in 2022. CEERS includes both images and data known as spectra from the microshutters aboard its NIRSpec (Near-Infrared Spectrograph). Data from CEERS were released immediately to support discoveries like this as part of Webb’s Early Release Science (ERS) program.