It presented the first image of the supermassive black hole

• Presented the first image of the supermassive black hole

At a press conference of the European Southern Observatory presented the results of the project EHT (Event Horizon Telescope) - the first image of the supermassive black hole located in the center of the M87 galaxy

April 10 around the world held several press conferences in which astronomers reported the results of a multi-year project EHT (Event Horizon Telescope, or "event horizon Telescope"). This project - the study of black hole located at the center of our galaxy, as well as in one of the neighboring galaxies, the M87 - with the help of just eight millimeter radio band radio telescopes scattered across the globe.

Nearly a hundred years of black holes are theoretical object. Their existence followed from the general theory of relativity, some space objects have behaved in such a way that the existence of black holes was the most natural explanation of their properties, but to register the direct signal from the black holes was not possible for a long time. Three and a half years ago, humanity for the first time been able to "hear" a black hole: the LIGO project to detect gravitational waves emitted by the merger of two black holes. Published today, the materials allow for the first time to "see" the object.

The quotation marks are necessary here because I see a black hole directly - to register the photons emitted by it - it is impossible (only the photons that emit black hole - Hokingovo radiation having a negligible energy and intensity). However, you can see the immediate neighborhood of the "event horizon", that is, the area where it can not escape no radiation. The gravitational field of the black hole distorts the trajectories of light rays can be said that the black hole casts a shadow. It was her and hoped to see the astronomers involved in the project. A black hole, or an object Sagittarius A *, located in the center of the galaxy, "Milky Way", shut away the gas and dust cloud near the galactic center. Thus, in the optical range to observe the object impossible. Observations airwaves prevents ionized gas. There is only a small window in the frequency millimeter wave band, and tools required for such observations became available only in the last decade.

Despite the enormous weight - about 4 million solar masses - our galactic black hole is a very compact object: its event horizon of 24 million kilometers in diameter would easily fit inside the orbit of Mercury. In order to observe such a small object at a distance of 26,000 light-years researchers had to apply the principles of interferometry long wheelbase. Eight telescopes participating in the project, located on different continents.

Another object of observation was a black hole in the center of the galaxy M87 in the constellation Virgo. This object has long attracted the attention of astronomers because it has a very high brightness at radio frequencies. Although it is much further away from us than the Sagittarius A * (about 55 million light-years), its location makes it more convenient for observation. Furthermore, this black hole is much heavier (6, 5 billion solar masses), and the radius of its event horizon than the size of the solar system.

The observations were carried out back in 2017, and the next two years, the data were processed. The total volume amounted to 4 petabytes of data (ie 4 million gigabytes) - this corresponds approximately to eight millennia of continuous music in mp3 format. To share these data with each other, the researchers had to carry on aircraft solid carriers: modern internet would not cope with such a task. Some of telescopes participating in the project. 1: The South Pole Telescope; 2: Large Millimeter / submillimeter telescope, Atacama, Chile; 3: Large Millimeter Telescope, Mexico; 4: The submillimeter telescope, Arizona; 5: Telescope James Clerk Maxwell, Hawaii; 6: 30-meter radio telescope IRAM, Spain

The result of observations submitted by April 10, was the first real image of a black hole in the world - namely, the one that is located in the center of the M87 galaxy. On the reconstructed image can be seen the dark "shadow" event horizon, as well as a rotating disc of matter falling into a black hole. Bending of light rays leads to the fact that we can see even those parts of the disk that are behind the black hole. One side of the disc noticeably brighter than the other: the reason is that the matter is rotated at a speed close to the speed of light, and the energy of the photons emitted by receding from the observer part of the drive, much less. The actual size of the black hole is about 2, 5 times smaller than its apparent "shadow".

It is expected that these results will help to test many of the physical theory describing the behavior of black holes. Description of these objects is based on the theories of quantum gravity, the development of which is still far from complete.

Previously, "see" the shadow of the black hole trying to Russian scientists at the Space Telescope "Radioastron". Its advantage is that it is working in a group with ground-based telescopes to form a virtual giant telescope the size of the earth to the height of its orbit. "Our goal was to see the shadow of the black hole at the center of the M87 galaxy. Was supposed to be lucky, "- explains Forbes Corresponding Member of RAS, scientific director of the program" Radioastron ", the head of research laboratories at FIAN and MIPT Yuri Kovalev.

However, researchers "unlucky": at the time of "Radioastron" were unknown to the absorption of radio waves in galaxies conditions. For the Russian telescope minimum wavelength - 1, 3 centimeters. Studies have shown that just in the centimeter range observed synchrotron self-absorption of radio emission from black holes in the centers of galaxies.

In this case, the results of "Radioastron" were taken into account in the EHT - from research groups have joint publications on the absorption spectrum of the dust.