Astronomers have observed enormous filaments of galaxies tied together with dark matter — the stuff scientists believe makes up 85 percent of the total mass of the universe — stretching across unfathomably vast distances.
Some of these behemoth structures have been observed to spin in the same direction, a dazzling and mysterious cosmic dance stretching across tens of millions of light-years, and a tantalizing clue in our efforts to understand how galaxies, and eventually stars, are formed.
Now, an international team of researchers led by the University of Oxford says it has spotted the largest one of these rotating structures ever identified using data from South Africa’s MeerKAT radio telescope, an array of 64 linked satellite dishes.
As detailed in a study published this month in the journal Monthly Notices of the Royal Astronomical Society, they observed 14 galaxies arranged in a “razor-thin” string that measures roughly 5.5 million light-years long and 117,000 light-years across. This structure is located inside a much larger filament that contains 280 other galaxies, reaching a length of 50 million light-years.
Many of these hundreds of galaxies appear to be rotating in the same direction as the overarching filament itself.
“This is the largest individual spinning structure so far detected,” colead author and University of Oxford postdoctoral researcher Lyla Jung told 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.”
The discovery suggests these structures can influence the spin of galaxies for longer, and more strongly, than previously thought.
“What makes this structure exceptional is not just its size, but the combination of spin alignment and rotational motion,” Jung said in a statement about the work.
“You can liken it to the teacups ride at a theme park,” she added. “Each galaxy is like a spinning teacup, but the whole platform- the cosmic filament -is rotating too. This dual motion gives us rare insight into how galaxies gain their spin from the larger structures they live in.”
The researchers suggest the filament is still fairly young after finding it’s in a “dynamically cold” state. The hydrogen-gas-rich galaxies within may still be gathering fuel to spit out stars, an intriguing glimpse into the earliest stages of a galaxy’s evolution.
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