An international team of astronomers has discovered the second most distant quasar ever found. Named Pōniuā`ena and designated J100758.264+211529.207 (J1007+2115), the object is around 13.1 billion light-years away, and contains a huge black hole with the mass equivalent to about 1.5 billion Suns, about twice as massive as that in the most distant known quasar ULAS J134208.10+092838.61. The existence of such a massive black hole just 700 million years after the Big Bang significantly challenges models of the growth of the earliest supermassive black holes.
An artist’s impression of the quasar Pōniuā`ena. Image credit: International Gemini Observatory / NOIRLab / NSF / AURA / P. Marenfeld.
“Pōniuā`ena is the most distant object known in the Universe hosting a black hole exceeding one billion solar masses,” said Dr. Jinyi Yang, a postdoctoral researcher at the Steward Observatory of the University of Arizona.
“For a black hole of this size to form this early in the Universe, it would need to start as a 10,000 solar mass ‘seed’ black hole about 100 million years after the Big Bang, rather than growing from a much smaller black hole formed by the collapse of a single star.”
Current theory suggests that at the beginning of the Universe following the Big Bang, atoms were too distant from one another to interact and form stars and galaxies.
The birth of stars and galaxies as we know them happened during the Epoch of Reionization, beginning about 400 hundred million years after the Big Bang.
The discovery of quasars like Pōniuāʻena, deep into the Reionization Epoch, is a big step towards understanding this process of reionization and the formation of early supermassive black holes and massive galaxies.
“How can the Universe produce such a massive black hole so early in its history?” said Professor Xiaohui Fan, an astronomer at the University of Arizona.
“This discovery presents the biggest challenge yet for the theory of black hole formation and growth in the early Universe.”
“Pōniuā`ena acts like a cosmic lighthouse,” said Professor Joseph Hennawi, an astronomer at the University of California, Santa Barbara.
“As its light travels the long journey towards Earth, its spectrum is altered by diffuse gas in the intergalactic medium which allowed us to pinpoint when the Epoch of Reionization occurred.”
The discovery is reported in the Astrophysical Journal Letters.
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Jinyi Yang et al. 2020. Pōniuā`ena: A Luminous z=7.5 Quasar Hosting a 1.5 Billion Solar Mass Black Hole. ApJL, in press; arXiv: 2006.13452
