Sunday , March 7 2021

Astronomers are discovering the most distant quasar

January 12, 2021

(News about Nanowerk) A team of astronomers observed a bright quasar 13.03 billion light-years from Earth – the farthest quasar ever discovered (“Redshift Light Quasar 7,642”).

A quasar – a luminous object with a supermassive black hole in the center – sheds light on how black holes grow. Dating 670 million years after the Big Bang, when the universe was only 5% of its current age, the quasar hosts a supermassive black hole equivalent to a total mass of 1.6 billion suns. quasar illustration An international team of astronomers has discovered the most distant quasar in space, fully formed about 670 million years after the Big Bang. At its center is a supermassive black hole, 1.6 billion more massive than the sun, surrounded by a swirling, overheated accretion disk. The object is the first of its kind to show evidence of a superheated gas leak coming out of a black hole environment at a fifth of the speed of light. (Image: NOIRLab / NSF / AURA / J. Da Silva)

In addition to being the most distant, and in a broader sense the earliest, known quasar, the object is the first of its kind to show evidence of an escaping wind of superheated gas coming out of a black hole environment at a fifth the speed of light. In addition to detecting a strong wind driving the quasar, the new observations also show intense star-forming activity in the host galaxy where the quasar is located, officially designated as J0313-1806.

Quasars are thought to be the result of supermassive black holes swallowing surrounding matter, such as gas or even whole stars, resulting in a vortex of overheated matter known as an accretion disk swirling around the black hole. Because of the enormous energies involved, quasars are among the brightest sources in the cosmos, often surpassing their host galaxies.

Although J0313-1806 is only 20 million light-years away from the previous recorder, the new quasar contains twice the weight of a supermassive black hole. This marks a significant advance for cosmology, as it provides the strongest restrictions on the creation of black holes in the early universe.

?? This is the earliest evidence of how a supermassive black hole affects its host galaxy around it, ?? said the journal’s lead author Feige Wang, a Hubble contributor from the Steward Observatory at the University of Arizona. ?? From observing less distant galaxies, we know this must happen, but we have never seen it happen so early in space. ??

Quasars that have already collected millions, if not billions of solar masses in their black holes, have posed a challenge to scientists trying to explain how they formed when they barely had time to do so. A common explanation for the formation of a black hole involves a star exploding like a supernova at the end of its life and crashing into a black hole. When such black holes fuse over time, can I ?? theoretically ?? grow into supermassive black holes.

However, much like it would take a lot of life to build a pension fund by investing dollars every year, quasars in the early universe are a bit like little millionaires; they must have gained their mass by other means.

The newly discovered quasar provides a new scale by excluding two current models of how supermassive black holes are formed in such short time frames. In the first model, massive stars that are mostly composed of hydrogen and that lack most of the other elements that make up later stars, including metals, form the first generation of stars in the young galaxy and provide food for the emerging black hole. The second model includes dense star clusters, which collapse into a massive black hole from the start.

The Quasar J0313-1806, however, has a black hole too massive to explain the aforementioned scenarios, according to the team that discovered it. The team calculated that the black hole at its center would have formed as early as 100 million years after the Big Bang and was growing as fast as possible, yet to begin with it would still have at least 10,000 solar masses.

?? This tells you that no matter what you do, the seed of this black hole must be formed by another mechanism, ?? said co-author Xiaohui Fan, regents professor and associate of the head of the Department of Astronomy UArizone. ?? In this case, one that involves large amounts of primordial, cold hydrogen gas that collapses directly into the seed black hole.

Since this mechanism does not require full-fledged stars as a raw material, it is the only one that would allow the supermassive black hole of quasar J0313-1806 to grow to 1.6 billion solar masses at such an early time in space. That’s what makes the new record quasar so valuable, Fan explained.

?? When you move to lower redshifts, all models could explain the existence of those less distant and less massive quasars, ?? He said. ?? In order for a black hole to grow to the size we see in J0313-1806, it would need to start with a seed black hole of at least 10,000 solar masses, and this would only be possible in a direct collapse scenario. ??

The newly discovered quasar seems to offer a rare insight into the life of a galaxy at the dawn of the universe when many galaxy-forming processes that have since slowed or stopped in galaxies that have existed for much longer are still in full swing.

UM astronomer Jiangtao Li contributes to this team on many related projects with X-ray observations of the most distant quasars, as well as optical spectroscopic observations of red-shifted ultraviolet absorption lines accompanying the gas that exists between the Earth and quasars. The latter project is mainly based on the 6.5-meter Magellan Baade telescope at the Las Campanas observatory in Chile, to which UM has privileged access.

?? The University of Michigan’s partnership in world-class optical / infrared telescopes, such as the double 6.5-meter Magellan telescope and the future ultra-large 39-meter telescope, will provide its researchers and students with many unique opportunities to study a variety of interesting objects in early space. said Lee. ?? These studies will play a crucial role in our understanding of the formation and development of supermassive black holes, galaxies, and larger structures during cosmic time.

The researchers presented their findings, which were accepted for publication in the Astrophysical Journal Letters, during a press conference and scientific talk at the 237th meeting of the American Astronomical Society, held January 11-15.

Source link