Ancient Cosmic Explosions May Explain Why the Universe’s Earliest Galaxies Died Young
Researchers discovered that supermassive black holes torched their host galaxies with violent winds just 1 billion years after the Big Bang, which could explain why so many early galaxies stopped forming stars.
An international team that includes a University of Maryland astronomer found powerful new evidence explaining how the earliest massive galaxies in the universe were suddenly robbed of their ability to form new stars. Using the James Webb Space Telescope (JWST), a team led by University of Arizona researchers detected enormous, fast-moving winds streaming from ancient quasars just 1 billion years after the Big Bang—explosions so powerful they may have blasted away the gas that galaxies would have needed to make new stars.
The researchers’ results, published in the journal Nature on May 6, 2026, offer a long-sought explanation for one of cosmology’s most persistent mysteries: why so many massive galaxies seem to have abruptly stopped forming stars within the universe’s first 2 billion years—far earlier than models predict they should have.
The study was led by Weizhe Liu (M.S. ’18, Ph.D. ’22, astronomy), a JASPER postdoctoral Fellow at the University of Arizona’s Steward Observatory and UMD alum advised by Astronomy Professor Sylvain Veilleux. Veilleux, a Fellow of the Joint Space-Science Institute and a co-author of the study, has spent decades studying galactic winds. He said the new results represent a turning point for scientists in the field.
“You can think of these galaxies having their star formation shut down early as having prematurely aged,” Veilleux explained. “The evidence for this premature aging has not been common, and this is really the first time it has been demonstrated in a sample of distant galaxies that is as unbiased as possible. Researchers have suspected it from numerical simulations but seeing it in action—basically catching it in the act of blowing the gas—is truly exciting.”
The team surveyed 27 luminous quasars (extraordinarily bright galactic centers powered by supermassive black holes) that existed when the universe was roughly a billion years old. Six of them showed extremely powerful galaxy-scale winds moving at speeds up to approximately 5,000 miles per second. That’s more than three to eight times the detection rate in similar quasars at later cosmic periods, and their average energy output was more than 300 times greater.
Quasars form when supermassive black holes devour surrounding gas, releasing a colossal amount of energy. Scientists long theorized that the resulting outflows could “quench” star formation entirely, but direct evidence has been elusive. Veilleux noted that the early universe was a uniquely potent setting for this process.
“It’s the perfect storm—a very bright quasar in the middle, surrounded by a lot of gas. These galaxies were just forming, gas-rich with material in all directions. Putting these two variables together produces those fast and powerful winds,” Veilleux explained. “Photons from the quasar push on the gas and, because the gas is everywhere, the result is like a huge spherical explosion blasting material outward in all directions at once.”
Researchers estimated that the extreme outflow quasars appear very short-lived, going dormant within 100 million years—a cosmic blink of an eye. The team calculated that every year, a galaxy with an extreme outflow quasar at its center would lose gas equivalent to thousands of solar masses (the total mass of the sun).
“That’s a very high rate of mass loss,” Liu said. “Apply that over the course of at least a million years, and you will see you can remove a lot of gas from an entire galaxy over a relatively short period of time.”
Because these outflows are so fast, Liu explained that they could escape the galaxy and possibly reach the intergalactic medium—the space between galaxies—expanding their potential impact.
“In other words, quasars could affect not only their host galaxies, but beyond, with their effects felt possibly hundreds of thousands of light-years away,” Liu said.
Veilleux noted that the expelled gas contains heavy elements such as carbon, nitrogen and oxygen.
“It’s not only that the gas won’t come back to form stars but also seeding the environment on a much larger scale,” he explained. “About half of the heavy elements in the universe are found outside the galaxies. These elements are also necessary for life. Quasars like these in the early universe can explain how those elements got there.”
The team hopes to expand their survey and observe fainter objects in the region until the next generation of extremely large ground-based telescopes allows them to study quasar winds with more detail and sensitivity.
“The implications of our findings go beyond star formation. It’s a way of ejecting material all the way to the intergalactic medium. Gas gets ejected on a much larger scale than we thought possible with quasars,” Veilleux said. “We will have to refine our data further, but the evidence is there now that quasars were a dominant force in the early universe.”
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The paper, “Extreme galaxy-scale outflows are frequent among luminous early quasars,” was published in Nature on May 6, 2026.
This research was funded by NASA (Contract Nos. NAS 5-02015 and NAS 5-03127), the Space Telescope Science Institute (Grant JWST-Survey-3428), the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, Fondecyt Iniciacion (Grant No. 11240336), Chile’s National Agency for Research and Development (Project No. FB210003). This article does not necessarily reflect the views of these organizations.
This article was adapted from text provided by the University of Arizona.
