A surprisingly massive black hole was discovered in the early Universe

An imposing black hole of 1.5 billion solar masses has been identified in the primordial Universe. It is located in the second most distant quasar known. The challenge is to understand how such a massive black hole could have existed so early.

Its mass represents 1.5 billion times that of our Sun: an impressive black hole was discovered in the primordial Universe. Its detection is detailed in an article, accepted in the review The Astrophysical Journal, available on arXiv since June 24, 2020.

« The existence of such a massive supermassive black hole just 700 million years after the Big Bang considerably challenges the patterns of growth of the first supermassive black holes Write the authors of this study. This black hole is housed in a quasar (a very bright galaxy core), named J1007 + 2115. This quasar is in itself a discovery, because it is the second most distant quasar ever identified, after J1342 + 0928 which was discovered in 2018. ” The supermassive black hole of J1007 + 2115 is twice as massive as that of the quasar J1342 + 0928 “, Complete the scientists.

“Source of invisible rotating creation”

The object was nicknamed “Pōniuāʻena” (“invisible rotating source of creation surrounded by brilliance”, in Hawaiian language). ” Pōniuāʻena is the most distant object known in the Universe hosting a black hole exceeding a billion solar masses “Summarizes Jinyi Yang of the Steward Observatory (Arizona), co-author of the study, quoted in a statement. In order for such a black hole to exist, it would theoretically have to begin its formation 100 million years after the Big Bang (as shown in the artist’s view above), with a starting mass of around 10 000 solar masses – instead of being born from a much less massive black hole, itself born from the collapse of a star.

The study of J1007 + 2115 and its black hole was made possible by the Gemini Observatory and the WM Keck Observatory, both located in Hawaii. The GNIRS instrument, from the Gemini observatory, made it possible to confirm the existence of Pōniuāʻena and to estimate the mass of its gigantic black hole.

A quasar formed at the start of reionization

How could such a massive black hole exist so early in the history of the Universe? This is the challenge of this discovery. The Universe is believed to be in its infancy – after le Big Bang – could not immediately form stars and galaxies, because the atoms were too far from each other. These objects may have formed during the reionization, a phase that occurred around 400 million years after the Big Bang.

Discovering a quasar like Pōniuāʻena, formed early in this period of reionization, is therefore an opportunity to learn more about the formation of the first supermassive black holes and large galaxies in the Universe.