American scientists who have studied energy emissions of quasars – the most powerful energy flows in the universe, have concluded that such emissions, like tsunami waves, push dust and gas outside galaxies, stopping the formation of stars. The results of the study are published in the Astrophysical Journal Supplies.
Quasars are the brightest objects in the universe. They occur when a supermassive black hole that is at the center of virtually every galaxy absorbs too much matter. At the same time gravitational energy of fall turns into heat and light, and from the center of black hole jets of gas and plasma are released, which accelerate to huge speeds, which make up several percent of speed of light.
Studying data from the Hubble Space Telescope, astrophysicists at Virginia Polytechnic concluded that the most powerful quasi-emissions could stop the formation of stars in the galaxy.
“Quasars are compact nuclei of distant galaxies that can shine a thousand times brighter than their galaxies, consisting of hundreds of millions of stars. Their central engines are supermassive black holes that are filled with falling dust, gas and stars, “said Nahum Arav, Professor of Physics at Virginia Technical College, in a university press release.
Scientists have found that quasars with powerful radiation appear when a collision of galaxies near a black hole accumulates a giant amount of gas. Thrown from a black hole in the form of jets, it warms up to a billion degrees, after which it begins to shine across the visible spectrum.
This gas, in the form of quasi-wind – extremely high-energy flows – like a tsunami, spreads through the disk of the galaxy, violently swept away in its path material from which new stars could form. As a result of this process, the quasar fades, and the galaxy itself stops the star formation process.
“These flows are crucial to understanding the process of galaxy formation,” Arav explains, “they push out hundreds of solar masses of material each year. The amount of mechanical energy these streams carry is several hundred times higher than the luminosity of the entire Milky Way galaxy. “
The results of the study showed that the radiation of the black hole pushes gas and dust over much greater distances than previously thought, it is a tsunami of galactic scale. According to the authors of the study, the observed effect explains the reason why scientists have not yet been able to detect a large number of large galaxies outside the Milky Way. Quasar tsunami probably heats up the gas and dust through which pass, creating a light spot that prevents the galaxies themselves from being seen.
When a galactic tsunami crashes into an interstellar material, its temperature increases dramatically, and the material begins to shine across the light spectrum, but above all, in X-rays.
“Anyone who witnesses this event will see a fantastic fireworks show,” says the scientist, “first you get a lot of radiation in X-rays and gamma rays, and then it will leak into the visible and infrared light zone.”
Both astrophysicist theorists and observer astronomers have long assumed that there is some physical process that stops star formation in massive galaxies, but the nature of this process was a mystery. This study shows that such powerful quasi-streams were to be distributed in the early universe.
One of the accelerated gas flows recorded by the authors had a record speed, which in three years of observation only increased – from 69.2 to 74 million kilometers per hour. It is the fastest and highest energy flow of matter ever seen in the universe.
