Astronomers have just found the oldest, most distant quasar, 13.03 billion light-years from Earth. It sheds light on how black holes form.
A team of astronomers from the University of Arizona has found the oldest, most distant quasar known. It lies 13.03 billion light-years away from Earth.
The previous record-holding quasar was also recently discovered, in 2017.
The quasar, dubbed J0313-1806, is only 20 million light-years farther away than its predecessor. But it hosts a supermassive black hole twice as heavy, 1.6 billion times more massive than the Sun. It dates back to 670 million years after the Big Bang when the universe was only 5% of its current age.
The quasar is an incredible 1,000 times more luminous than our entire Milky Way galaxy.
Scientists revealed this discovery on Tuesday at the 237th meeting of The American Astronomical Society, happening virtually due to the pandemic. The study has been accepted for publication in The Astrophysical Journal Letters.
A quasar is the core of a galaxy resulting from a supermassive black hole that devours everything near it. The quasar, which throws off enormous energy, is surrounded by a whirlpool of superheated plasma about the size of a solar system. It shines brighter than the entire Galaxy.
Quasars are the most distant celestial objects and are crucial to understanding the early universe.
In addition to being the oldest and most distant quasar ever found, the newfound object is the first of its kind to show evidence of an outflowing wind of super-heated gas escaping from the surroundings of the black hole at a fifth of the speed of light.
“This is the earliest evidence of how a supermassive black hole is affecting its host galaxy around it,” said the paper’s lead author Feige Wang, a Hubble Fellow at the Steward Observatory of the University of Arizona. “From observations of less distant galaxies, we know that this has to happen, but we have never seen it happening so early in the universe.”
“The most distant quasars are crucial for understanding how the earliest black holes formed and for understanding cosmic reionization — the last major phase transition of our Universe,” said Xiaohui Fan, study coauthor and regents professor of astronomy at the University of Arizona, in a statement.
The formation of the quasar, however, remains a bit of a conundrum.
The existence of such a massive quasar at a very early time in the universe poses a challenge to scientists trying to explain how they came into existence when they barely had the time to do so.
Typically, black holes are byproducts of exploded stars that have died and collapsed. Such black holes merge and grow over time, forming supermassive black holes. Quasars, on the other hand, are supermassive black holes on steroids. However, quasars in the early universe are far too young to have become so huge, so quickly, in this way.
But the quasar provides a new benchmark. It also rules out two current models of how supermassive black holes form in such short timescales.
In the first model, massive stars consisting largely of hydrogen and lacking most other elements that make up future stars, including metals, form the first generation of stars in a young galaxy and provide the food for the baby black hole. The second model involves dense star clusters, which collapse into a massive black hole right from the outset.
But the newly found quasar hosts a black hole too massive to be explained by these models. The team calculated that if the black hole at its center formed as early as 100 million years after the Big Bang and grew as fast as possible, it still would have had to have at least 10,000 solar masses to begin with.
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“This tells you that no matter what you do, the seed of this black hole must have formed by a different mechanism,” said Xiaohui Fan.
The team of scientists suggests huge amounts of cold hydrogen gas are responsible instead.
“In this case, one that involves vast quantities of primordial, cold hydrogen gas directly collapsing into a seed black hole.”
The newfound quasar is still growing. Its brightness indicates the black hole is gobbling up about 25 stars like our sun each year. Thus, powering an outflow of gas moving at 20% the speed of light.
This loss of gas, a necessary ingredient in star formation, typically halts the birth of stars in a galaxy.
“We think those supermassive black holes were the reason why many of the big galaxies stopped forming stars at some point,” Fan said.
Ultimately, the black hole will eventually run out of food, stunting its growth, Fan said.
Scientists discovered the quasar using a variety of observatories around the world, including several telescopes in Hawaii.
The galaxy that hosts the quasar is rapidly producing stars at a rate 200 times faster than the Milky Way.
The quasar offers a rare glimpse into galaxy formation at the beginning of the universe. But scientists hope to uncover more about the quasar’s secrets with future more powerful telescopes. NASA’s James Webb Space Telescope, slated to launch this year, will allow a more detailed investigation.