The giant ring of galaxies that challenges knowledge about the Universe – 01/12/2024 – Science

Scientists at the University of Central Lancashire have discovered a gigantic ring-shaped structure in space.

It is a structure that is 1.3 billion light years in diameter.

Located more than 9 billion light-years from Earth, it cannot be seen with the naked eye, but its diameter in the night sky would be equivalent to 15 full moons.

Called the Great Ring by astronomers, it is made up of galaxies and clusters of galaxies.

Because it is so large, scientists say this ring challenges our understanding of the Universe.

The Great Ring cannot be seen with the naked eye. It is very distant and identifying all the galaxies that make up its larger structure required a lot of time and computational power.

These large structures should not exist, according to one of the guiding principles of astronomy, called the cosmological principle. This theory states that all matter is spread smoothly throughout the Universe.

Although stars, planets and galaxies are enormous clumps of matter to our eyes, in the context of the size of the Universe they are insignificant — and the theory is that much larger clumps of matter should not form.

The Great Ring is by no means the first likely violation of the cosmological principle, and therefore suggests that there is another factor at play, yet to be discovered.

According to Robert Massey, deputy director of the Royal Astronomical Society, evidence is growing that it is necessary to rethink this central pillar of astronomy.

“This is the seventh major structure discovered in the Universe that contradicts the idea that the cosmos is smooth on the largest scales. If these structures are real, then it is definitely food for thought for cosmologists and accepted thinking about how the universe has evolved over the years.” time,” he said.

The Great Ring was identified by Alexia Lopez, a postdoctoral student at the University of Central Lancashire (UCLan), who also discovered the Giant Arc — a structure spanning 3.3 billion light-years of space.

Asked what it was like to make the discoveries, she said it was all very “surreal”.

“I have to pinch myself, because I made these discoveries accidentally, they were fortuitous discoveries,” he says.

“Neither of these two giant structures is easy to explain in our current understanding of the Universe,” she said.

“And their sizes, distinct shapes and cosmological proximity must certainly be telling us something important — but what exactly?” he asked.

Both the Great Ring and the Giant Arc are relatively close together, near the constellation of Boötes the Bull.

Professor Don Pollacco, from the physics department at the University of Warwick, said the probability of this occurring (two giant structures so close to each other) is very small, so the two objects could be related and form an even larger structure. .

“So the question is how were such large structures created?” he says.

“It is incredibly difficult to conceive of any mechanism that could produce these structures, so instead the authors speculate that we are looking at a relic of the early Universe, where waves of high- and low-density material are ‘frozen’ in an extragalactic medium. “

There are also equally large structures discovered by other cosmologists — such as the Sloan Great Wall, which is about 1.5 billion light-years long, and the South Pole Wall, which stretches 1.4 billion years — light.

But the largest entity identified by scientists is a supercluster of galaxies called the Hercules-Corona Borealis Great Wall, which is about 10 billion light-years wide.

Although the Great Ring appears to be a nearly perfect ring in the sky, Lopez’s analysis suggests that it has a more spiral shape — like a corkscrew — with its face aligned with the Earth.

“The Great Ring and the Giant Arc, both individually and together, bring us a great cosmological mystery as we work to understand the Universe and its development.”

The findings were presented at the 243rd meeting of the American Astronomical Society (AAS) in New Orleans.