In a groundbreaking study published in the journal Nature, astronomers using the James Webb Space Telescope (JWST) have detected three infant galaxies amidst a primordial cloud of hydrogen and helium gas, just 400 to 600 million years after the Big Bang. This remarkable observation marks the first time astronomers have witnessed the birth of galaxies, offering a window into the enigmatic era of reionization.
During this pivotal period, the earliest stars and galaxies emerged from the dense gas clouds that enveloped the universe, ionizing the gas and transforming it into the transparent cosmos we know today. By analyzing the ancient galaxies’ spectra, the research team found evidence that light from three of them was being absorbed by large amounts of neutral hydrogen gas. This suggests that these galaxies were actively assembling neutral hydrogen gas into new stars.
Lead study author, an assistant professor of astrophysics at the Cosmic Dawn Center (DAWN) at the University of Copenhagen, emphasized the significance of the discovery: ‘These galaxies are like sparkling islands in a sea of otherwise neutral, opaque gas. Without Webb, we would not be able to observe these very early galaxies, let alone learn so much about their formation.’
The detection of these infant galaxies brings astronomers closer to understanding the nature of the gas clouds that once obscured the universe and the emergence of the first galaxies that illuminated it. Further observations with JWST are expected to shed even more light on this transformative era in the history of the cosmos.
