Scientists have discovered the oldest known to date quasars. Discovered quasars - this is a very large and active black holes, which are located in the center of galaxies. Their mass is very large - they weigh from 100 million to 10 billion solar masses. Surrounding a supermassive black hole is rotating disk of dust and gas. The inner rings rotate faster than the outer disk.
Matter, moving disks, rubs and heated, which causes it to emit light. The inner rings are heated so much that they begin to emit X-rays, a ring positioned slightly farther from the black hole emit ultraviolet light of the ring located further emit visible light and the farthest emit infrared radiation. Although the area of radiation emitted is very small (it is equal to the size of our solar system), the radiation is so powerful that it can be observed even in the most remote corners of the universe.
Huge black holes
"Quasars - this is a very early stage of evolution of galaxies, galaxy-kind child," - explained Vastergaard Marianne (Marianne Vestergaard), an astrophysicist at center for the study of dark matter and energy at the University of the Niels Bohr - "Most galaxies have a massive black hole mass More than a million suns, but not quasars. quasars have a black hole is in active growth. gravity of the black hole gradually pulls the surrounding dust and gas into the black hole, gradually making it heavier and bulkier. absorbed by the black hole matter is replaced by a new one that is taken out of the galaxy and the cycle repeats again. Eventually Quasars are among the most massive objects in the universe, second only to the galaxies. "
But why quasars are so similar to each other? Scientists have been asked this question, and their recent study discovered something else. Marianne Vastergaard, together with colleagues from Germany and the USA, studied 21 quasar in a distant part of the universe, the age of 800 million years old (real age of 13.7 billion years, the difference between the observed and the actual age, due to the very large distance you need to travel light).
"We found that all quasars, except two, there was a large accumulation of dust. We wondered what caused the lack of dust in the two quasars," - she said.
Witnesses formation of the first black holes
There are signs that the two most distant quasar found in very young galactic systems that contain less dust, and where black holes grow rapidly. Scientists have found that those remote quasars that found in galaxies with large amounts of dust were smaller than those found in areas with a large amount of gas. And quasars with large black holes, there was a lot of dust in the center. Perhaps this is due to the fact that black holes grow "up" with the rate of formation of stars in the galaxy. A large number of stars, produces a large amount of dust.
The farther you look in the universe, the more the age of what you see and those galaxies, astronomers are looking for, which will study the formation of the first dust in the universe. Dust has had a huge impact on what, when, and how stars were formed.
"Obviously, we have found what is most likely a primitive first-generation quasars, born in bezpylnom space shortly after the Big Bang, and that we can observe in the initial stage of evolution. Since quasars are growing rapidly both black holes and dust, it is means that we have found a young galaxy that has long been looking for. fact that we had the opportunity to observe the formation of black holes and the heavy particles in the form of dust - is a big success, "- added Marianne Vastergaard. We will tell you the exciting news from the horse’s mouth.