Scientists have discovered the precession of a relativistic jet emanating from a supermassive black hole in the center of the galaxy M87. It and its accretion disk rotate like a giant spinning top and emit a large amount of gaseous material into space.
Is a supermassive black hole spinning
Chinese scientists have recently published a study according to which a supermassive black hole in the center of the neighboring galaxy M87 is still spinning. This is exactly the object that the Event Horizon Telescope received an image of a few years ago. Since then, it was the question of its behavior that worried scientists the most.
Supermassive black holes are giant objects which can have billions of times the mass of our Sun. As to whether they rotate, there are numerous disputes among scientists. But what they are sure of is that the substance that falls on them by itself begins to spin, forming a disk. And part of it escapes from the poles of the black hole in the form of relativistic jets.
By the way, such a jet was discovered for the first time at the black hole in the Center of M87. It happened back in 1918. However, in order to study it properly, interferometry on an ultra-long base was needed, so observations were made from different points of the Earth separated by thousands of kilometers. This became possible only in the XXI century.
Observations of the jet
In order to study the relativistic jet from the M87 black hole, scientists used more than 20 astronomical instruments scattered from China to Italy. Perhaps the largest of them was the 65-meter Tianma radio telescope. In general, the research lasted from 2000 to 2023, and finally scientists were able to present their result.
The main conclusion they managed to make was that the relativistic jet experienced precessions with a period of 11 years. This phenomenon is well known to everyone who has ever untwisted a spinning top. At some point, the axis of its rotation begins to loosen from side to side. The Earth’s axis behaves in a rather similar way.
However, in all these cases, the reason for precession is external influences. In the case of the spinning top — the gravity of the Earth, and in the case of our planet — the Sun. However, the supermassive black hole in M87 is too big for something to shake it like that.
However, scientists could find an answer to this question and it allowed us to make the conclusion that not only the accretion disk, but also the black hole rotated. The fact is that the substance from the inside of the gas-dust “dish” falls on the central object all the time. And the relativistic effects caused by its spin make it behave quite strangely.
In fact, precession is caused by the interaction of two rotating motions: the black hole and its disk. However, the difference between the two speeds was so small that it took 20 years of observations to accurately measure and explain all this.
According to phys.org
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