Mystery of the most powerful objects in the Universe capable of "bleeding out" galaxies solved
The brightest and most powerful objects in the Universe, called quasars, are created by the collision of galaxies. This explains their powerful luminescence, the origin of which scientists have been unable to unravel for decades.
The results of the study, led by scientists from Sheffield and Hertfordshire, will be published in the journal Monthly Notices of the Royal Astronomical Society.
Quasars were first discovered 60 years ago. Subsequent observations have shown that they can shine as brightly as a trillion stars occupying a space similar in size to our solar system.
For decades after their discovery, scientists were very interested in their power, but they were always stumped because they could not explain it.
The answer was discovered when scientists used the Isaac Newton Telescope in La Palma to observe structures in the outer regions of galaxies that are home to quasars.
Most galaxies have supermassive black holes in their centres and also contain a significant amount of gas, most of which is beyond the reach of the black holes.
However, when a collision occurs between galaxies, all of the galactic gas is forced towards the black hole. Just before the gas is swallowed up, it releases an extraordinary amount of energy in the form of radiation, which leads to the characteristic brilliance of a quasar.
In addition to being a very bright and powerful spectacle, it can also be almost "deadly", as it can force the remaining gas out of the galaxy. As a result of such an event, the galaxy may remain incapable of forming new stars for billions of years.
Comparing observations of 48 quasars and their galaxies with images of more than 100 non-quasar galaxies, the researchers concluded that galaxies containing quasars are about three times more likely to interact or collide with other galaxies.
"Quasars are one of the most extreme phenomena in the universe, and what we are seeing probably represents the future of our Milky Way galaxy when it collides with the Andromeda galaxy in about five billion years," said Clive Tudhunter, Professor of Physics and Astronomy at the University of Sheffield.
Quasars are important to astrophysicists because their brightness makes them stand out over long distances and can serve as beacons to the earliest epochs in the history of the Universe.
"Quasars play a key role in our understanding of the history of the universe and possibly the future of the Milky Way," explained postdoctoral researcher at the University of Hertfordshire, Dr Johnny Pierce.
Earlier, OBOZREVATEL also told about the discovery of scientists who learned that stars can destroy life on planets under one condition.