Scientists have made an exciting discovery about galaxies in a massive filament of dark matter. Most of these galaxies are spinning in the same direction as the filament itself. This finding could change our understanding of how galaxies evolve over time.
This filament is a part of the cosmic web, mainly made of dark matter, with some ordinary matter mixed in. It stretches across the universe and is located about 140 million light-years away. Inside this filament, researchers found a line of 14 galaxies. These galaxies stretch 5.5 million light-years and are rich in hydrogen gas, essential for star formation. Overall, this filament contains around 300 galaxies.
What’s remarkable is that many of these galaxies are rotating in sync with the filament. Imagine galaxies as spinning teacups. While each one spins on its own, the entire platform—representing the cosmic filament—rotates too. This dual motion allows scientists to see how larger structures influence the spinning of galaxies.
Lyla Jung, an astrophysicist at the University of Oxford, compared this to a ride at a theme park. “It’s unique because we see how galaxies can gain their spin from the structures around them,” she said in a statement.
Jung and her colleague Madalina Tudorache used the MeerKAT radio telescope in South Africa for this study. They tracked the motion of hydrogen gas in the galaxies and the filament. They supplemented this data with optical observations from the Dark Energy Spectroscopic Instrument in Arizona and the Sloan Digital Sky Survey in New Mexico.
In a study released last year, astronomers found that cosmic filaments were revolving, based on the movement of galaxies within them. This new finding adds an extra layer of complexity, revealing that the galaxies themselves are also turning in harmony with the filament. This runs counter to established beliefs about how galaxies form.
For example, in our Milky Way galaxy, gas, stars, and dust rotate around the center, taking about 220 million years to complete one orbit. This initial spin comes from the gas cloud that formed the galaxy, which has passed its momentum onward. Over billions of years, galaxies often collide or merge, complicating their spins.
What makes this filament important is its potential to guide gas flow to the galaxies, influencing their rotation and fueling the birth of new stars. Tudorache noted, “This filament acts like a fossil record of cosmic flows, shedding light on how galaxies evolve.” The galaxies in this filament appear relatively young, suggesting their spins may change as they mature.
This discovery hints at adjustments needed in current galaxy formation models. Surprisingly, the effects of material flowing along cosmic filaments are more significant than previously understood. And it’s not just theoretical; these findings might affect real-world measurements too. For instance, weak lensing surveys, which detect distortions in galaxies caused by dark matter, will benefit from a clearer understanding of how galaxies align and rotate along filaments.
The full details of this study were published on December 4 in the Monthly Notices of the Royal Astronomical Society. These insights pave the way for a better grasp of the universe’s structure and galaxy formation.
For further reading, you can check the original study published by the Royal Astronomical Society.
