Astronomers have discovered a razor-thin chain of 14 hydrogen-rich galaxies, all embedded in a much larger cosmic filament about 50 million light-years long and located roughly 140 million light-years from Earth.

 

Astronomers have discovered a razor-thin chain of 14 hydrogen-rich galaxies, all embedded in a much larger cosmic filament about 50 million light-years long and located roughly 140 million light-years from Earth.

This narrow structure measures around 5.5 million light-years in length but only about 117,000 light-years across, making it an extraordinarily slender, rotating bridge of galaxies on truly intergalactic scales.​

Using South Africa’s MeerKAT radio telescope, operating in the MIGHTEE deep survey, the team traced cold hydrogen gas in these galaxies, then combined this view with optical data from DESI and the Sloan Digital Sky Survey to map their motions in 3D. The analysis revealed that galaxies on opposite sides of the filament’s spine move in opposite directions, implying that the entire filament is rotating with a characteristic speed of about 110 km/s and a dense central radius of roughly 50 kiloparsecs (163,000 light-years).​

What makes this discovery remarkable is the coherent alignment: many galaxies spin in the same direction as the filament itself, far more often than random chance would allow. This suggests that large-scale cosmic structures do not merely host galaxies, but actively shape their spin, gas content, and star formation histories over tens of millions of light-years.

As a dynamically cold, gas-rich, and seemingly young structure, this rotating filament offers a rare fossil record of how angular momentum flows through the cosmic web—an insight that will sharpen models of galaxy evolution and help interpret future surveys with Euclid and the Vera C. Rubin Observatory.​

RESEARCH PAPER

Madalina N. Tudorache et al., “A 15 Mpc rotating galaxy filament at redshift z = 0.032”, Monthly Notices of the Royal Astronomical Society (2025)