Find the oldest cluster of galaxies

International astronomers announced the discovery of a cluster of galaxies formed in the first phase of the universe more than 13 billion years ago.

By observations from three Subaru, Keck, and Gemini telescopes, an international team led by Yuichi Harikane from Japan National Astronomical Observatory found a cluster of 12 giant galaxies, called is Protocluster . At over 13 billion years old, only about 800 years of the Big Bang, this is the oldest cluster of galaxies ever known in the universe.

Image of 12 members of the Protocluster galaxy cluster.(Photo: Scitech Daily).

Of the 12 members of the Protocluster cluster, one galaxy was found 10 years ago, called Himiko . It is a huge cloud of gas located 500 million light-years from the center of the galaxy cluster. "It's hard to understand why a large object like Himiko is not at the center. However, this clue may be the key to understanding the relationship between galaxies and giant clusters," said Masami Ouchi, Co-author of the study said.

In the present universe, galactic clusters may contain hundreds of members, but how they grow into clusters is still a big question in astronomy. The discovery of early clusters of galaxies, such as the Protocluster, is very significant, which could help scientists understand more about their formation.

"Protocluster is a rare, special system, extremely high density and not easy to find," Yuichi described. "To overcome this problem, we used the Subaru telescope's wide field of view to map a large area of ​​the sky and search."

The team's findings were published in the Astrophysical Journal on September 27.

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