Astronomers find impossibly large black hole of early universe.
WASHINGTON -- An international team of astronomers said Wednesday they have found an ancient black hole so big that it challenges theories on how they form and grow in the early universe.
The mass of the black hole, which formed only 900 million years after the Big Bang, is 12 billion times that of the Sun, and a shining object called quasar, produced by the black hole as it actively accretes surrounding materials, is 420 trillion times more luminous than our Sun, they reported in the British journal Nature.
"This is the brightest quasar ever discovered in the early universe, powered by the most massive black hole yet known at that time," said a statement released by the team led by Xue-Bing Wu at Peking University, China.
The black hole, located at a distance of 12.8 billion light years from our Earth, was first spotted by a 2.4-meter telescope in Lijiang in southeast China's Yunnan Province and was confirmed in follow-up studies with three other telescopes in the United States and Chile.
Team member Xiaohui Fan, professor from the University of Arizona's Steward Observatory, said the discovery "presents a major puzzle" to the theories of black hole growth in the early universe.
"How can a supermassive black hole grow so quickly when the universe was so young? It's very hard to interpret it with current theories," Fan told Xinhua.
There may be two explanations for it, he continued. One is that the original seeds of supermassive black holes in the early universe, which formed by the collapse of dead stars, can be larger than previously thought; the other is that the black holes of that time can accelerate their surrounding materials at an unexpected high speed.
The researchers believed that the quasar with this black hole may provide a unique laboratory to the study of the mass assembly and galaxy formation around massive black holes in the early universe.
"We are so excited, when we found that there is such a luminous and massive quasar only 0.9 billion years after the Big Bang," team leader Wu of Peking University said. "Just like the brightest lighthouse in the distant universe, its glowing light will help us to probe more about the early universe."