The new quasar is the second farthest found so far, more than 13 billion light-years away from Earth.
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Agencies
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Using the Gemini and Cerro Tololo observatories, an international team of astronomers has just discovered the most massive quasar found so far in the early Universe, with a black hole inside whose mass is equivalent to 1.5 billion suns, ABC reported.
Quasars are the most energetic objects in the Universe, and since their discovery in the late 1950s, astronomers and cosmologists have tried to find out when they first appeared in our cosmic history.
The new quasar is the second farthest found so far, more than 13 billion light years away from Earth, but its tremendous mass doubles that of the only other quasar found at the same time, just 700 million years after The Big Bang, the finding, which has been possible after a decade of observations, challenges current theories of the formation and growth of supermassive black holes and galaxies in the early Universe.
The Gemini Observatory is made up of two twin 8.1-meter telescopes, located in the two hemispheres of Earth. One, the North Telescope, is on the dormant Mauna Kea volcano in Hawaii, and the other, the South Telescope, is located in Cerro Pachón, Chile. Together, the two telescopes manage to cover the entire sky in both hemispheres throughout the year. The Cerro Tololo Inter-American Observatory, meanwhile, consists of five telescopes and is located a short distance from the Gemini Sur telescope in Chile.
In honor of its discovery through a telescope in Maunakea, a mountain revered by Hawaiian culture, the quasar was given the indigenous name of Pōniuāʻena, which means “invisible rotating source of creation, surrounded by brilliance.” It is the first quasar to receive a Hawaiian name.
According to current theory, quasars are “powered” by supermassive black holes. As black holes gobble up surrounding matter, such as dust, gas, or even entire stars, they emit huge amounts of energy, and a brightness that dwarfs that of entire galaxies. And Pōniuāʻena is one of the two most distant discovered so far. According to the study that will appear soon in Astrophysical Journal Letters and that is already available on the ArXiv prepublication server, it took exactly 13.020 million years for the light of this quasar to cover the distance that separates it from our planet and the telescopes that have made it observed. Which means that Pōniuāʻena already existed barely 700 million years after the Big Bang, a time so remote that the Earth and the Sun still needed about 8,000 million years to start forming.
“It is the first monster of its kind that we know of,” says Jinyi Yang, a researcher at the Steward Observatory at the University of Arizona and the lead author of the study. “And we don’t know how it has had enough time to go from being a small black hole (like theory says) to be the enormous size we have observed. “
Indeed, the delicate question of how such a huge black hole can come into existence when the entire Universe was still in its infancy is something that has haunted astronomers for a long time. According to Xiaohui Fan, co-author of the research, “the discovery poses the greatest challenge for the current theory of black hole formation and growth in the early Universe.” In fact, it’s hard to keep thinking that a black hole the size of Pōniuāʻena could have evolved from the collapse of a single star in such a short time since the Big Bang.
The seed of a black hole
According to the authors, another possible explanation should rather be considered: that the quasar began its existence as a black hole “seed”, one that already had at least 10,000 solar masses just a few tens of millions of years after the Big Bang.
Pōniuāʻena was discovered through a nearly ten-year systematic search for the most distant quasars. The team discovered a possible quasar in the data and, in 2019, finally observed it with multiple telescopes.
“The observations with Gemini,” explains Feige Wang, another of the authors of the work, “were critical in obtaining the high-quality near-infrared spectra that gave us the amazing mass of the black hole.”
The discovery of a quasar at the dawn of creation has provided researchers with a rare insight into a time when the Universe was very young and completely different from today. Current theories suggest that, shortly after the Big Bang, the atoms were still too hot to interact with each other, bond, and begin to form stars and galaxies, which did not emerge until about 400 million years after the great explosion, in the called “Epoch of Reionization”.
So the discovery of quasars like Pōniuāʻena just then is an extremely important step in understanding how the first massive galaxies arose. Pōniuāʻena has imposed new and important restrictions on the evolution of matter in that distant time.
“It seems that this quasar,” explains Fan, “existed right at the midpoint of the Reionization era, and the fact that we can observe objects like this will help us understand what happened.”
Back in 2018, the same team announced the discovery of what remains the most distant quasar found so far, but its mass is practically half that of Pōniuāʻena. Designated as J1342 + 0928, that object is, in addition, only two million years older (and far) than Pōniuāʻena, a difference that according to Fan, who participated in both discoveries, is quite insignificant by cosmic standards,.
“Two million light years between 13,000 million,” concludes Fan, “makes it quite close to a draw.”
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