To the universe was made, it took several million years for the first light to shine over the cosmos. The first stars began to form, and so did ancient galaxies. When the gas and dust in the center of these galaxies begin to revolve around their supermassive black holes, they form the brightest objects in the entire universe – quasars.
Quasars give us a glimpse of what the universe looked like in its infancy, and scientists can look back on these cosmic animals through telescopic time travel.
A team of researchers recently announced the discovery of the farthest quasar ever observed, dating from 670 million years after the Big Bang. The quasar was accompanied by the oldest black hole ever observed. But the extreme age of this black hole is not the only notable feature – it is absolutely (super) massive. Nor can scientists explain how it reached its extreme size.
The discovery was announced Tuesday at the 237th Session of the American Astronomical Society and is set out in a study accepted for publication in the Astrophysical journal letters.
HERE IS THE BACKGROUND – Quasars were discovered in the 1960s. Their name is derived from the fact that they are ‘quasi-star objects’, as a single quasar emits the same amount of light as a trillion stars, while occupying a space smaller than our solar system.
Scientists believe that quasars form when galaxies have an abundant amount of gas and dust around the black holes in their center, which eventually spin around and form a growth disk of overheated material that spins around.
Because of their high energy, quasars often exceed the galaxies they house.
What’s new – Scientists hunt for these ancient animals while informing them about the conditions of the early universe and how galaxies formed and evolved over time. In addition, quasars can also help scientists better understand the connection between galaxies and the black holes in their middle.
A team of scientists from the University of Arizona was able to locate the farthest quasar ever observed, which was located 13.03 billion years ago from Earth. This means that the quasar existed when the universe was only 670 million years old – only five percent of its current age (astronomers believe that the universe is 13.8 billion years old).
The quasar, called J0313-1806, is more than ten billion times as bright as the Sun and has about a thousand times more energy than the entire Milky Way.
The quasar offers a supermassive black hole in its center, with a mass of 1.6 billion Suns. Compared to the supermassive black hole in the middle of the Milky Way, which is 13.67 million times the mass of the sun, it’s a pretty big boy.
Recent observations also show that the quasar, according to the study, has a stream of superheated gas that flows in the form of a rapid wind from the vicinity of the black hole.
This is what we do not know – Scientists are confused about how this supermassive black hole could have formed so early in the universe and become so large. In other words, how did it take time to eat up so much surrounding material to reach its massive size?
“Black holes created by the very first massive stars could not have become so large in just a few hundred million years,” said Feige Wang, NASA Hubble Fellow at the University of Arizona and lead author of the new article, said in a statement.
Scientists believe that black holes are formed after the death of a massive star, an explosive supernova, or by feeding the first generation of stars that form in a galaxy. They then grow over time by swallowing material that surrounds them.
The team behind the new study calculated that if the black hole had formed after the big bang as early as 100 million years ago and would grow as fast as possible, it would still be about 10,000 solar masses and not the huge 1.6 billion it is currently using. does not boast.
“It tells you that no matter what you do, the seed of this black hole must have been formed by a different mechanism,” said Xiaohui Fan, co-head of the Department of Astronomy at the University of Arizona and co-author of the study. a statement.
“In this case, one that involves large amounts of original, cold hydrogen gas that pours directly into a seed-black hole.”
In addition to being too large for its own good, the black hole also consumes the mass equivalent of 25 Suns each year. Scientists believe that supermassive black holes of this size in the early universe were the main reason why ancient galaxies stopped forming stars, with their black holes collecting all the gas and other materials needed for baby stars from birth.
WHAT IS NEXT – The rather turbulent relationship between black holes and their host systems in the early universe, gives scientists a rare opportunity to study how galaxies have formed and evolved over time, and the effects of their supermassive black holes on their growth.
The researchers hope to make further observations of this quasar, and to find more of these quasars in the early universe, following the launch of NASA’s James Webb Telescope, currently scheduled for October 31, 2021.
Summary: Remote quasars are unique trackers to study the formation of the earliest supermassive black holes (SMBHs) and the history of cosmic reionization. Despite extensive efforts, only two quasars were found at z ≥7.5, due to a combination of their low spatial density and the high pollution rate in the quasar selection. We report the discovery of a light quasar at z = 7.642, J0313−1806, the farthest quasar still known. This quasar has a bolometric brightness of 3.6 × 1013L⊙. Deep spectroscopic observations reveal an SMBH with a mass (1.6 ± 0.4) × 109M⊙ in this quasar. The existence of such a massive SMBH, just about 670 million years after the big bang, challenges the theoretical models of SMBH growth. In addition, the quasar spectrum exhibits strong broad absorption line (BAL) functions in CIV and SiIV, with a maximum velocity of almost 20% of the light velocity. The relativistic BAL characteristics, combined with a strongly blues-shifted CIV emission line, indicate that there is a strong active galactic core (AGN) driven outflow in this system. ALMA observations detect the dust continuum and [CII] emission of the quasar host system, giving an accurate redshift of 7.6423 ± 0.0013, indicating that the quasar is housed by an intense star-forming galaxy, with a star-forming rate of ∼200 M⊙ yr-1 and a dust mass of ×7 × 107 M⊙. Follow-up observations of this BAL quasar from the re-ionization period will provide a powerful investigation into the effects of AGN feedback on the growth of the earliest massive galaxies.