A recent study using the James Webb Space Telescope and the Atacama Large Millimeter/sub-millimeter Array has uncovered fascinating insights about 70 dusty, star-forming galaxies located at the edge of the universe. These galaxies existed less than 1 billion years after the Big Bang and might reshape our understanding of cosmic evolution.
Remarkably, researchers have found that these galaxies contain a surprising amount of “metals”—elements heavier than hydrogen and helium—despite being formed well before the current models suggest these elements could be created. Jorge Zavala, a team leader from the University of Massachusetts Amherst, noted that “dusty galaxies are massive and rich in metals and cosmic dust.” This indicates that star formation was happening much earlier than previously believed.
The journey to these discoveries began with the Atacama Large Millimeter/sub-millimeter Array in northern Chile, which identified 400 bright and dusty galaxies. Further analysis with the James Webb Space Telescope narrowed this down to 70 faint candidates, most of which had never been seen before. These galaxies date back as far as 500 million years after the Big Bang.
This finding hints that our current story of cosmic history may require a rewrite. These dusty galaxies connect to two other types identified earlier by the James Webb Telescope: young, ultrabright galaxies and older, inactive galaxies. Zavala describes them as a lifecycle snapshot—ultrabright are the youth, while the inactive ones are like retired elders. The newly discovered galaxies are the young adults, bridging these two phases.
Future research will be crucial to determine how these three populations of galaxies relate to one another. The connections could show that our understanding of galactic evolution is missing key elements. Recent studies suggest that stars must have begun forming much earlier in the cosmos than we currently theorize. Data like this is vital for expanding our grasp of the universe’s evolution.
The team’s findings were published in The Astrophysical Journal Letters on February 17. As we continue to study the depths of space, we may find even more surprises awaiting us.
