Current DateSeptember 19, 2021

Astronomers find a “monstrous” quasar in the primitive universe

A team of astronomers claims to have identified the presence of an incredibly massive quasar very early in the Universe. Details of the study are published in The Astrophysical Journal Letters.

A quasar is a very energetic galaxy with, at its center, a very active nucleus. These nuclei are said to be “active” due to the presence of a supermassive black hole accreting matter. The object then emits a lot of energy in the form of electromagnetic radiation (radio, IR, visible, UV, X), and therefore appears very bright. Quasars, in a way, present themselves as luminous versions of black holes.

What astronomers are announcing to us today is the discovery of the most massive quasar ever identified in the primitive universe. The latter, containing a black hole with a mass equivalent to 1.5 billion suns, has been observed as it evolved 13.02 billion years ago. About 700 million years after the Big Bang alone.

Officially known as J1007 + 2115, the newly discovered quasar is one of only two known to be identified during the same cosmological period. Spotted by Mauna Kea Observatories, the object has just been named Pōniuāʻena, in honor of Hawaiian culture. Which roughly means “invisible source of spinning creation, surrounded by brilliance”.

Explain the presence of such massive and active objects

Quasars are the most energetic objects in the Universe. Since their discovery, astronomers have sought to determine when these objects may have appeared in the first place. In addition, the question is also how such massive black holes can materialize so early in cosmic history.

In this sense, this new discovery partially answers at least one of these questions. 13.02 billion years ago, we know that these objects were there. On the other hand, it is not yet known how such “monsters” could have formed in such a short time.

Indeed, according to current theory, after the Big Bang, the atoms were too far from each other to interact and form stars and galaxies. The birth of these first objects finally occurred in the so-called “reionization” era, some 400 million years later.

Thus, for researchers, the idea that a black hole displaying such proportions can evolve from a smaller black hole, itself formed by the collapse of a single star, all in such a short time, is almost impossible. At least according to current cosmological models.

One of the avenues explored for several years to explain the formation of these objects suggests that they are born from imposing clouds of gas which collapse on themselves. These black holes, finally skipping the intermediate stages, would then already be massive in the first place (at least 100,000 solar masses), before then growing at a normal rate.

Regarding the object that interests us today, researchers suggest that it formed around 100 million years after the Big Bang. It would then have evolved normally, eventually becoming the cosmic ogre that it was 600 million years later.

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