Galaxies merge. In the center of a single object formed by them, scientists found a star absorbed by a supermassive black hole.Supermassive black holes are quite difficult to detect. In most cases, indirect observations of the centers of galaxies, as well as mathematical calculations, help. But nevertheless, their activity can theoretically be traced - in some cases jets of plasma generated from the star's matter are thrown into space. Jets move away from the feast in space at a very high speed. On these "remains" astronomers can judge the activity of black holes.
The other day
it became known that a joint team of astronomers from Finland and Spain discovered signs of the process of absorbing a star by a supermassive black hole. At the scene, scientists recorded plasma jets thrown out at a very high speed, which are better known among astronomers as
relativistic jets .
Actually, they can be called “known” with a stretch, since the existence of such jets was predicted theoretically, but there was practically no evidence. Scientists only conducted a computer simulation of this phenomenon and roughly imagined how things might look. Now all these data were useful, since astronomers were able to detect the place where the star was absorbed by the black hole due to jets. Experts do not assert yet that these are relativistic jets with one hundred percent probability, but most likely they are.
“We have never before observed the formation and evolution of a jet formed in such a situation,” said Miguel Perez-Torres, head of the research team. Scientists have discovered an outbreak not now, but back in 2005. For ten years, astronomers have observed the evolution of the discovered phenomenon. Interestingly, in 2005, experts came to the conclusion that they were observing supernova because the flash was similar to what happens in the case of a supernova explosion: a sharp, very rapid increase in brightness and the release of just a huge amount of energy. Such flares are usually not associated with black holes, their cause is the internal processes of the evolution of stars. However, in subsequent observations, astronomers were convinced that this was not a supernova, but a reason for the increase in brightness in something else.
The object, which was observed by scientists, was named
Arp 299 . In fact, these are two galaxies, IC 694 and NGC 3690, which merge with each other. This kind of union leads to the destabilization of vast stellar regions. Part of the stars leaves the usual trajectories of motion, collisions often occur, dust and gas are actively released. And since the scale of the collision is galactic, the volumes of dust and gas emitted by objects are simply enormous.
Star dust formation processes began in the dust and gas clouds of the Arp 299 object, which was also recorded by scientists.
Some stars fall into the trap, passing near the galactic centers, where the largest black holes. The latter absorb the luminaries, which release jets. Some of them are visible light, but still astronomers are still unable to catch it, because the jet is very far away and the light does not reach or almost does not reach us. The intensity of visible radiation, which still gets to the Earth - is very weak. Therefore, the observation is carried out in the infrared range.
So, using infrared and radio telescopes, scientists watched a star, whose mass is several times higher than solar. She was dangerously close to one of two galactic centers with a supermassive black hole. According to scientists, the mass of this object is 20 million times the mass of the Sun.
Naturally, the gravity of the black hole did not leave the star any chance - it was just broken. Moreover, the astronomers were lucky to observe a rare phenomenon - the release of a jet. In this case, not all the matter of the star fell beyond the horizon of events - a part of the matter was “shot” into space at a speed of a quarter of the speed of light.
According to experts, the observation of the Arp 299-B AT1 jet makes it possible to better understand the formation of such structures during the absorption of a star by a black hole. Relativistic jets are still a poorly understood phenomenon, so now is the time to study the information received in detail.
Some astronomers suggest that the release of a substance into outer space when a star is absorbed by a black hole occurs more often than is commonly believed. But due to the fact that black holes are often surrounded by dense dust-gas clouds, such phenomena cannot be observed with the help of modern astronomical tools - their capabilities are far below the level required for detecting jets.