The largest known rotating galaxy filament has been detected: a razor-thin chain of 14 galaxies about 5.5 million light-years long, embedded within a roughly 50 million light-year filament that contains ~280 additional galaxies. Observations with the MeerKAT radio telescope show many member galaxies rotating in the same direction as the filament. The structure appears dynamically cold and hydrogen-rich, suggesting it is relatively young and still forming stars, and offers new insight into how galaxies acquire spin from cosmic flows.
Astronomers Discover Largest Known Rotating Galaxy Filament — A Razor-Thin Chain Spanning 5.5 Million Light-Years
An international team of researchers says it has spotted the largest rotating structure of dark matter and gas-rich galaxies.
Scientists have identified the largest individual rotating structure of galaxies yet observed: a razor-thin filament of 14 galaxies that spans roughly 5.5 million light-years and sits inside a far larger cosmic filament about 50 million light-years long.
An international team led by the University of Oxford used data from South Africa’s MeerKAT radio telescope — an array of 64 linked dishes — to map the structure and measure the motions of gas and stars within it. The findings appear this month in the Monthly Notices of the Royal Astronomical Society.
What the team found
The researchers detected a narrow string roughly 5.5 million light-years long and about 117,000 light-years across composed of 14 galaxies. That string lies inside a much larger filament that contains about 280 additional galaxies and stretches roughly 50 million light-years. Many of the galaxies in both the thin strand and the larger filament show coherent rotation in the same direction as the filament itself.
“This is the largest individual spinning structure so far detected,” said co‑lead author Lyla Jung, a postdoctoral researcher at the University of Oxford, speaking to Reuters. “Statistically, we believe there are other spinning structures, some of which could be larger. However, we have not been able to detect them directly with our current data and telescopes.”
Why it matters
The discovery strengthens evidence that large-scale cosmic structures — filaments of galaxies bound by dark matter — can influence how galaxies acquire their spin. The team describes the filament as being in a "dynamically cold" state and rich in hydrogen gas, suggesting it is relatively young and that its member galaxies may still be accreting material and forming stars.
“What makes this structure exceptional is not just its size, but the combination of spin alignment and rotational motion,” Jung said in a statement. She likened the system to a theme-park teacups ride: each galaxy spins like a teacup while the entire cosmic platform — the filament — rotates, offering a rare window into how galaxies inherit angular momentum from larger-scale flows.
Co‑lead author Madalina Tudorache, a postdoctoral research assistant at the University of Cambridge, called the filament “a fossil record of cosmic flows.” The paper also maps how hydrogen gas is being channeled and swirled inside the filament, data that can guide follow-up observations with upcoming facilities such as the European Space Agency’s Euclid mission and the Vera C. Rubin Observatory.
Looking ahead
As radio and optical surveys improve, astronomers expect to find more of these rotating filaments and better understand their role in galaxy formation and evolution. The discovery demonstrates the growing power of instruments like MeerKAT to reveal the dynamics of large-scale structure in the universe.
