, Svetlogorsk district, Gomel region, Belorussian SSR Belorussian SSR

Russia, Russia

Nikolai Ivanovich Shakura(belor. Mikalay Ivanavich Shakura, October 7, Danilovka village, Parichsky district, Bobruisk region, BSSR) - Soviet and Russian astrophysicist, Doctor of Physical and Mathematical Sciences (), professor. In 1999, together with R. A. Syunyaev, he developed the theory of accretion disks, which underlies the modern theory of X-ray binary systems.

Biography

Father - Shakura Ivan Matveevich, lieutenant of the Soviet army, veteran of the Great Patriotic War, was demobilized due to injury and went to work as an accountant on a collective farm. Mother - Shakura (Sidorova) Serafima Stepanovna, a native of Tatarstan. The family raised four sons. Nikolai graduated from primary school in his native village, 7-year-old school in the village of Kovchitsy-2, Parichi district, and secondary school in the urban village of Parichi (with a gold medal).

Scientific works

Honorary titles and awards

• Honored Researcher, Moscow State University. M. V. Lomonosova ()
• Prize of the 2nd degree named after. M. V. Lomonosov Moscow State University. M. V. Lomonosova ()
• "Outstanding Scientist" of the RIKEN Institute (Japan, )
• Silver medal “For successes in the national economy of the USSR” Exhibition of Achievements of the National Economy of the USSR ()

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An excerpt characterizing Shakur, Nikolai Ivanovich

After the clash at Vyazma, where Kutuzov could not restrain his troops from the desire to overturn, cut off, etc., the further movement of the fleeing French and the fleeing Russians behind them, to Krasnoye, took place without battles. The flight was so fast that the Russian army running after the French could not keep up with them, that the horses in the cavalry and artillery became weak and that information about the movement of the French was always incorrect.
The people of the Russian army were so exhausted by this continuous movement of forty miles a day that they could not move faster.
To understand the degree of exhaustion of the Russian army, you only need to clearly understand the significance of the fact that, having lost no more than five thousand people wounded and killed during the entire movement from Tarutino, without losing hundreds of people as prisoners, the Russian army, which left Tarutino numbering one hundred thousand, came to Red in the number of fifty thousand.
The rapid movement of the Russians after the French had just as destructive an effect on the Russian army as the flight of the French. The only difference was that the Russian army moved arbitrarily, without the threat of death that hung over the French army, and that the backward sick of the French remained in the hands of the enemy, the backward Russians remained at home. The main reason for the decrease in Napoleon's army was the speed of movement, and the undoubted proof of this is the corresponding decrease in Russian troops.

Nikolai Ivanovich, you and Rashid Alievich received the state prize for creating the theory of disk accretion of matter onto black holes. How did you start working on this topic?

There was a person who determined our development with Rashid Syunyaev. This is Yakov Borisovich Zeldovich - academician, three times Hero of Socialist Labor.

In the mid-60s, Yakov Borisovich got the opportunity to work at Moscow University. In my opinion, it was 1966 when the name Zeldovich appeared in our schedule. “The structure and evolution of stars” was the name of his course. I went to his first lecture. Those who wanted to write term papers with him stayed after the lecture. It was my turn - it’s impossible to forget such things, and he asked if I had been to his seminar the day before. And he had a Joint Astrophysical Seminar (JAS) here at SAI twice a week. The most interesting discoveries were reported there.

At one seminar there was a story about X-ray sources - their nature was unknown then. I was at that seminar. And Zeldovich gives me a task: here is a neutron star with a radius of 10 km, matter falls on its surface, and a powerful shock wave with very high temperatures appears near the surface. This wave should emit X-rays. “Calculate the structure and spectrum of radiation from this shock wave...” And I began to calculate it.

It was only a couple of weeks later that I learned that this was a neutron star gas accretion problem. That was the first time I heard the word “accretion.” I thought I was being played, because at first Academician Zeldovich did not use this term. I found it in the Latin dictionary accretio- an increase in something, an increase in something. I then solved the problem.

- So your acquaintance with Academician Zeldovich began with accretion?

Yes, it turns out so. Two people played a very large role in the beginning of our accretion activities. This is Zeldovich Yakov Borisovich and Martynov Dmitry Yakovlevich, director of our institute, SAI, - he lectured on the course of general astrophysics. And he talked about close double stars, where there is a flow of matter from one to the other. I then thought: “What if we put a black hole instead of the second star?” There is a lot of gas that flows out from the second component. Due to the movement of this binary star system, a ring forms around the black hole and spreads out into a disk.

For your work with academician Rashid Syunyaev you received the State Prize for Science. Please tell us more about her.

Our work with Rashid Sunyaev was carried out more than 40 years ago. The late 60s - early 70s were a wonderful time for astronomy: objects such as neutron stars and black holes in double star systems were discovered.

X-rays do not pass through the Earth's atmosphere, so observations in the X-ray spectrum can only be made outside the Earth's atmosphere. In the mid-60s, a group of American scientists, led by Riccardo Giacconi, installed X-ray counters on a rocket and launched it above the Earth's atmosphere. They hoped to discover X-rays from the Moon, but discovered some mysterious sources that were far from the solar system. At that time, our scientific supervisor, Academician Zeldovich, suggested that we study the nature of these x-ray sources.

In the early 70s, Professor Giacconi's group launched a special X-ray satellite to study these objects. It was discovered that these X-ray sources are part of binary star systems, where in addition to the X-ray source there is an ordinary optical star. It loses matter, the matter falls onto a compact object, and what we now call an accretion disk forms around it. And the process of disk accretion begins, as a result of which the matter in the disk, rapidly rotating like a satellite around a gravitating center, slowly settles onto this source as momentum is lost. A disk is formed, the disk emits energy. Most of this energy is emitted in the X-ray region of the spectrum from the inner parts of the disk, close to the compact object. These were the results of our calculations. Ours was published in 1973.

It so happened that the work turned out to be very fundamental and has been cited for many years. We now have more than eight thousand references to this work in the scientific literature.

As far as I understand, this area was of interest to many astrophysicists at that time. And your work gave the simplest and most beautiful explanation.

Yes, the simplest and most elegant. In the 60s, X-ray sources were discovered, the study of the sky in the X-ray range up to the Uhuru satellite went like this: instruments were placed on rockets, they took off above the earth’s atmosphere, and something was measured within ten minutes.

Time passed, and in 1967 radio pulsars were discovered. This discovery was made by a team of scientists led by Anthony Hewish in England, with Jocelyn Bell playing a decisive role. And most of the people who are involved in the astrophysics of black holes and neutron stars have switched to the study of pulsars - these are neutron stars that emit radio radiation in a narrow cone, the star rotates, and a radio pulsar is obtained. For a while, radio pulsars eclipsed everything. But we continued to study accretion neutron stars, black holes in binary systems.

At first, radio pulsars were single. Much later, in 1975, Taylor and Hulse would discover a radio pulsar in a binary system. However, a little earlier, in the early 70s, the time had come for the Uhuru satellite, which discovered accreting neutron stars in the X-ray range. There are radio pulsars, they slowly slow down over time, the source of their observed activity is rotational energy. And there is another type of neutron stars - these are accretion X-ray pulsars in binary star systems. It was them that “Uhuru” discovered. There is a disk there, there is a neutron star with a strong magnetic field. Somewhere at one hundred radii of the neutron star, the magnetic field destroys the disk, matter from the disk begins to fall along magnetic field lines onto the neutron star in the region of the poles. The neutron star has hot poles, it rotates, and we again get a pulsar, but in the X-ray range of the spectrum. These neutron stars shine by releasing gravitational energy.

And if there is a black hole there, then the disk that we calculated exists up to the radius of the last stable orbit: the gravitational field of the black hole is so strong that, starting from a certain distance, particles begin to fall along the radius towards the black hole.

- Your work still finds application in other areas of astrophysics. Why?

There are accretion disks around black holes, neutron stars, there are accretion disks around white dwarfs in binary star systems, or around ordinary stars in binary star systems. And the calculations we made are suitable for a wide variety of situations. Recently, a huge number of protoplanetary disks have been discovered, to which our theory is also applicable.

The most intriguing objects exist in the nuclei of active galaxies and quasars - supermassive ones with a mass of tens of hundreds of millions and even up to a billion solar masses. And there, too, disk accretion takes place.

Some time ago, a black hole was discovered at the center of our Galaxy. It turned out to be a million or so solar masses. Accretion processes also take place there. But there may not be such a continuous disk, and gas clouds are falling onto the black hole.

-Are you working on this now?

My youth and I are working on the most important problem that has been solved in recent years - how matter in this accretion disk gives up its angular momentum and gradually falls onto this accretion center. There must be a certain viscosity in this disk, as a result of which accretion occurs. If there is ordinary, ionic, atomic viscosity, then it is very small. We introduced turbulent viscosity and viscosity associated with magnetic fields. Now we are studying the question of the nature of turbulent viscosity in accretion disks.

There are standard Shakura-Sunyaev discs, which are also called alpha discs. In this theory, there is a dimensionless alpha parameter that characterizes both turbulence in the disk and chaotic magnetic fields. The alpha parameter represents the ratio of viscous friction forces to pressure forces. This parameter alpha is not greater than 1, but greater than 0. When it is of the order of 1, the turbulent velocities that arise in this disk become transonic, and shock waves appear. My young colleagues - candidate of physical and mathematical sciences Galina Lipunova and a very young graduate student Konstantin Malanchev, who is about to defend his PhD thesis - have created programs that calculate non-stationary accretion disks.

In addition to stationary X-ray sources, X-ray novae are now known. These are sources that appear in the sky, shine brightly for a couple of weeks, and then their shine subsides. Based on the characteristics of the brightness decay, one can determine what the alpha parameter is equal to in these accretion disks. And it turns out to be 0.3−0.5, it is not so small. There the turbulence is close to transonic.

- What other areas of astronomy, besides accretion, are you involved in?

Astronomy is a very interesting and rich science. There are a variety of objects, a variety of stars. For example, I had a job like this. Mercury's orbit moves slightly differently than predicted by Newton's classical theory of gravity. There is motion of the apsidal line, the orbit is eccentric, and the major axis of the ellipse experiences some additional motion that could not be explained within the framework of the classical Newtonian theory of gravity. But Einstein's theory of relativity was able to explain these extra 40 seconds per century.

There are double stars in eccentric orbits that also experience apsidal motion, that is, motion of the major axis of the ellipse. Many observers test the effects of relativity in such systems. It turned out that there is such a double system of DI Hercules, where the apsidal movement is not explained. Part of this movement is due to the fact that the central stars are not points; the mass in these stars is distributed. The law of gravity differs from the purely Newtonian one, because each of the stars is deformed both by its own rotation and by mutual tides. An additional contribution to apsidal motion comes from the effects of general relativity. Typically, when calculating the effects of apsidal motion, it is assumed that the torque vectors of each of the components are parallel to the orbital rotation vector. And this is true for most systems. However, after some thought, I placed the rotation vector of one of these DI Hercules stars in the orbital plane. With this configuration, the classical theory gives different figures, and in this case everything can be explained while remaining within the framework of the general theory of relativity. That's what the job was like.

As a result of precision spectral observations of DI Hercules, which were carried out later, this configuration was confirmed.

- You said that the 60s were a wonderful time. And now?

Yes, for us the 60-70s of the 20th century were the golden age of astrophysics. Then, too, there were wonderful people who made discoveries before us. When we started working, it seemed to us that our work was the most important. And now discoveries that will remain for centuries will be made by young people.

- Which of the young Russian astronomers can you single out?

A lot of our young people work abroad: in the USA, Germany, England. But they don't lose touch with us. My co-author, academician Rashid Alievich, is the head of a laboratory at the Space Research Institute of the Russian Academy of Sciences, and at the same time he works as one of the three directors of the Max Planck Institute for Astrophysics in Germany. There are a lot of our young people there. They work there for a while, here for a while.

- Which area of ​​astrophysics interests you most now?

Oh, one can only envy scientists now. This is the discovery of gravitational waves made by American scientists from LIGO. The first cases were discovered in September 2015; by the end of 2015, three cases of black hole mergers had already been discovered. In January of this year, another pair of merging black holes was discovered. The merger occurs very quickly, a stream of gravitational waves comes from it, which is measured by high-precision interferometers. The black holes discovered during the merger process turned out to be somewhat more massive than those black holes that are studied by their X-ray emission from accretion disks in binary star systems. The masses of the latter are approximately 5-15 solar masses. In my opinion, 22 such black holes have already been discovered in binary star systems.

And from the characteristics of the gravitational wave impulse, one can estimate both the masses and the actual rotation of these black holes. And the mass of each of them turned out to be from 20 to 30 solar masses. I wonder how they formed in the distant past, why they turned out to be more massive. One of the options for stellar evolution with the formation of such massive black holes is contained in the work of Russian scientists, Professor Konstantin Postnov and Candidate of Physical and Mathematical Sciences Alexander Kuranov, which was published just a few days ago.

The merger of two neutron stars is expected to be discovered. Perhaps the merger of a neutron star and a black hole, but this is in the future.

And the second interesting area is our Universe as a whole, cosmology. Dark matter has been discovered there, which is somehow distributed in clusters of galaxies, and there is also dark energy. And the density of this dark energy is the greatest: if the total density of matter in the Universe is taken as 1, then the dark energy accounts for 0.7. This is also interesting.

Another interesting discovery is the accelerated expansion of the Universe. It was previously thought that gravity caused the rate of expansion to slow down over time. And now it turns out that the expansion of our Universe is not slowing down, but accelerating. This phenomenon is called inflation. It was characteristic of the early stages of the Universe, and now we are again entering a regime of accelerated expansion of the Universe. The nature of this regime is successfully explored in the works of Russian academician Alexei Starobinsky.

Planets are also interesting, because several planets have been discovered with a mass on the order of the mass of the Earth. And they exist in a zone where life is possible, like on our Earth.

Almost 50 years ago, the discoveries were colossal: neutron stars, black holes, cosmic microwave background radiation. It was discovered then, and now the distribution of its fluctuations across the sky is being studied. The cosmic microwave background radiation itself has a temperature of 2.7 degrees Kelvin, and fluctuations are 10 microkelvins or even less. And from these fluctuations people study the history of our Universe and its expansion. In those distant 70s, Rashid Syunyaev and academician Yakov Zeldovich predicted the effect named after them (the Sunyaev-Zeldovich effect). The essence of the effect is that the spectrum of the relict radiation is slightly deformed as a result of the scattering of relict photons by electrons of very hot gas, which is contained in large quantities in galaxy clusters. Nowadays, this effect has been discovered and is successfully observed by radio telescopes around the world. The magnitude of the effect provides important information about the parameters of our expanding Universe.

Nikolai Ivanovich, you have devoted your whole life to the study of space. Have you ever wanted to visit there? Were you jealous of the astronauts?

I was in 9th grade when Gagarin flew. And, of course, I had dreams that I would most likely connect my life with space. In 1963, I finished 11th grade - I studied in Belarus - and went to enter Moscow University. When I went to the admissions office, I saw an announcement that there was such an astronomy department and there was a separate admission and competition for it - about 20-25 people. I thought it had something to do with space. But it turned out to be astronomy; we don’t have such a direct connection with space as cosmonauts have. But I'm happy with how everything turned out.

On June 12, the Kremlin hosted the presentation of the 2016 Russian State Prize for outstanding achievements in the field of science and technology, literature and art, and humanitarian work. Among its laureates is the head of the department of relativistic astrophysics of the State Astronomical Institute named after P.K. Sternberg Moscow State University Nikolai Shakura. He received the award with the wording “for creating the theory of disk accretion of matter onto black holes” together with his colleague and co-author, a graduate of Moscow State University, academician of the Russian Academy of Sciences, head of the laboratory of the Space Research Institute of the Russian Academy of Sciences Rashid Sunyaev. In his speech at the award ceremony, Nikolai Shakura thanked Moscow University, which gave him higher education and where he continues his scientific activities, the rector of Moscow State University, academician V.A. Sadovnichy, remembered his teacher Yakov Zeldovich, and also promised to “continue to actively work for the benefit of our Fatherland, involving the younger generation of Russian scientists in this work.”

The researchers' work is related to the theoretical study of black holes, or more precisely, the matter that falls into black holes. While rotating, it cannot immediately fall onto a compact object and forms a disk around the black hole - this phenomenon is called “disk accretion”. As a result of the transition of gravitational energy into thermal energy, these disks begin to glow strongly, and most of the energy comes out in the form of X-rays. This makes accreting black holes one of the strongest sources of X-ray radiation.

The work for which the prize was awarded was done in the early 1970s, as were the first discoveries of accreting black holes. In those theoretical articles, according to Nikolai Shakura, a lot was predicted: spectra, variability, the influence of magnetic fields. Modern instruments, more advanced than those that existed at that time, as well as new observations confirm the results obtained several decades ago.

One of the predictions was jets - directed flows of matter ejected by astronomical objects such as galaxies, quasars and neutron stars. They also appear during accretion near black holes. Scientists mentioned the possibility of jet formation in their work, but they were discovered after the work of N. Shakura and R. Sunyaev. However, the mechanisms of their formation have not yet been fully explained.

In the article “Standard theory of disk accretion onto black holes and neutron stars” published in 1973 in the journal Astronomy and Astrophysics, N. Shakura and R. Sunyaev described a model of disk accretion in which the “alpha parameter”, which describes turbulent viscosity, plays a key role. The parameter is a numerical coefficient less than unity, estimated based on observations. The model turned out to be quite convenient, which ensured the success of the article, which is considered the most cited article in world theoretical astrophysics. It also helped to understand the observations of the first orbiting X-ray laboratory, NASA's UHURU satellite, which discovered X-ray pulsars, X-ray emissions from galaxy clusters, and mapped the X-ray sky.

Since the paper was published, many new matter-accreting black holes have been discovered. Among the fundamentally new results obtained in the field of studying these extreme bodies recently, the astrophysicist names the detection of gravitational waves from merging black holes. “Just as X-ray astronomy was emerging in the 1970s, so now astronomy is emerging, astrophysics of gravitational wave radiation, black hole mergers,” explained Nikolai Shakura.

Nikolai Ivanovich Shakura was born in 1945 in the Gomel region of the Belarusian SSR. He graduated from school with a gold medal, after which he entered the Faculty of Physics of Moscow State University, where he studied under the guidance of the Soviet physicist Yakov Zeldovich. Having graduated from the university in 1969 with a degree in astronomy, N. Shakura remained in graduate school and defended his dissertation on the topic “Physical processes in the vicinity of neutron stars and frozen stars.” 16 years later, after defending his dissertation on the topic “The Theory of Disk Accretion and Its Some Astrophysical Applications,” he received the degree of Doctor of Physical and Mathematical Sciences. N. Shakura is the founder of the modern theory of accretion. A year before the publication of the famous article, in 1972, he began working at the SAI MSU, where he now heads the department of relativistic astrophysics created by his teacher, Ya. Zeldovich.

The 2016 Russian State Prize laureates were astrophysicists Rashid Sunyaev and Nikolai Shakura.

N.I. Shakur and R.A. Syunyaev in the conference hall of the traffic police, 1979. (Photo from the archives of the photo laboratory of the SAI MSU)

Nikolai Ivanovich Shakura (photo by O. S. Bartunov, SAI)

Rashid Alievich Sunyaev (Photo: Artem Korzhimanov, ru.wikipedia.org)

Badge of honor for the laureate of the State Prize of the Russian Federation.

They received the award for the theory of disk accretion of matter onto black holes created in the early 1970s, which became generally accepted and formed the basis of the modern theory of binary systems, which are powerful sources of X-ray radiation.

Their seminal paper, “The Standard Theory of Disk Accretion onto Black Holes and Neutron Stars,” published in 1973 in the journal Astronomy and Astrophysics, is considered the most cited paper in theoretical astrophysics worldwide.

The fall of matter onto a celestial body due to its gravitational attraction is called accretion (from the Latin “increment”). Matter falling onto a compact object with very strong gravity, a black hole or a neutron star, cannot immediately fall on it and forms a rapidly rotating disk around it. This phenomenon is called disk accretion.

In this case, matter is accelerated by gravity to speeds close to the speed of light. The collision and mutual friction of such high-speed gas flows heats them up to temperatures of tens and hundreds of millions of degrees. This leads to enormous energy emission, mainly in the X-ray range, which consumes up to 0.3 of the rest energy of the falling matter.

The luminosity of such a source reaches 10 36 -10 39 erg/s, which is thousands and millions of times greater than the luminosity of the Sun. This mechanism explains the emergence of the most powerful sources of radiation in the Universe. It is applicable for binary systems, where one of the components is a neutron star or black hole, as well as for accretion onto supermassive black holes, which helps explain the radiation of quasars and galaxies.

It is worth noting that the idea of ​​a powerful energy release during non-spherical accretion of matter onto a black hole was expressed back in 1964 by academician Ya.B. Zeldovich, whose students are both laureates. Zeldovich pointed out the fundamental possibility of observing black holes in the X-ray range of the spectrum.

The publication of the work by R. Sunyaev and N. Shakura coincided with the beginning of systematic observations of the sky by the American orbital X-ray observatory UHURU (NASA), which in 1972-1975 discovered X-ray pulsars, X-ray emission from galaxy clusters and obtained a map of the sky in the X-ray range with hundreds of X-ray sources radiation.

The theory of disk accretion made it possible to understand the nature of most of these objects as accreting neutron stars and black holes in close binary systems, where the second component was a normal optical star. To date, the number of known X-ray binary systems reaches hundreds of thousands.

Domestic astrophysicists under the leadership of R. Sunyaev studied in detail the properties of such sources using the KVANT-1 X-ray observatories at the MIR station (1987-2001), the GRANAT satellites (1989-1999) and INTEGRAL (since 2002) and discovered a large number of new objects.

In theoretical articles of the 1970s, according to N. Shakura, a lot was predicted: spectra, variability, the influence of magnetic fields. Modern instruments, more advanced than those that existed at that time, as well as new observations confirm the results obtained several decades ago.

One of the predictions was jets - directed streams of matter ejected at enormous speed due to the interaction of the accretion disk with the magnetic field by such astronomical objects as galaxies, quasars, neutron stars and black holes. However, the mechanisms of jet formation have not yet been fully explained.

Currently, Doctor of Physical and Mathematical Sciences Nikolai Ivanovich Shakura is the head of the department of relativistic astrophysics of the State Astronomical Institute named after P.K. Sternberg Moscow State University, and Academician of the Russian Academy of Sciences Rashid Alievich Sunyaev is the head of the laboratory of theoretical astrophysics and scientific support of the Spektr-RG project of the department of high astrophysics Energy Institute of Space Research RAS

Based on materials MSU press service

The famous astrophysicist has recently been a leading researcher at the Research Laboratory "X-Ray Astronomy" of the SAE "Astrocall" KFU.

We talked with Nikolai Ivanovich Shakura, Doctor of Physical and Mathematical Sciences, Professor, Head of the Department of Relativistic Astrophysics at the State Astronomical Institute named after P.K. Sternberg Moscow State University, a member of the International Astronomical Union and the European Astronomical Society. By the way, the minor planet N14322 in the solar system (Shakura) is named in honor of the scientist.

This year, N. Shakura, together with Honorary Professor of Kazan University, Chief Researcher of the Institute of Space Research of the Russian Academy of Sciences, Director of the Max Planck Institute of Astrophysics (Germany), Academician of the Russian Academy of Sciences R. Syunyaev “for creating the theory of disk accretion of matter onto black holes” received the State Prize of the Russian Federation Federation. The Shakura-Sunyaev theory became the basis for the modern theory of close binary systems with accretion of matter.

– Nikolai Ivanovich, what will you do as an employee of the X-ray Astronomy research laboratory?

– The name of the laboratory speaks for itself. Together with KFU astronomers, we will model double star systems with black holes, with neutron stars... Both on the basis of optical observations, and, especially, on the basis of X-ray observations.

You've probably heard about the Spektr-Roentgen-Gamma space observatory, which is planned to be launched in September 2018 with the goal of compiling a detailed X-ray map of the Universe and a “census” of cosmic objects emitting in the X-ray range?

Yes. Employees, graduate students, undergraduates and students of the Department of Astronomy and Space Geodesy of KFU will participate in the processing, analysis and interpretation of data from the Spektr-RG observatory. In addition, KFU astronomers will provide optical support for the observatory with observations on the RTT-150 telescope installed in Turkey.

– So, this satellite will host two telescopes: the German one - eROSITA, which is designed for observations in the soft X-ray range, and the Russian one - ART-XC, its task is to conduct observations in the hard X-ray range. The research topics of the Spektr-RG space observatory will be very diverse. For example, we expect that processes associated with the destruction of stars flying near supermassive black holes located in the cores of active galaxies will be discovered in large numbers. I think it will be possible to observe an interesting phenomenon: a star being torn apart by tides from a supermassive black hole. Of course, a huge number of supermassive black holes and galaxy clusters will be discovered...

– Probably, with the help of the Spektr-RG satellite, ordinary binary systems with black holes and neutron stars, to which you dedicated your first lecture at KFU in November of this year, will also be studied?

- Undoubtedly!

– Your childhood coincided with the beginning of the space age, did this fact somehow influence your choice of profession?

– The most powerful impression of childhood was Gagarin’s flight into space in 1961. I was in 9th grade then. After school, I was going to enter the Belarusian State University at the Faculty of Physics, since I lived in Belarus, not far from Bobruisk. But when I graduated from 11th grade, my father advised me to go to Moscow and apply to Moscow State University.

That's exactly what I did. What helped me successfully pass the exams at Moscow State University was that for a year and a half I solved problems from the collections for applicants to Moscow State University, which I wrote out. When I arrived to submit documents, I found out that, in addition to the main physics department, there was an astronomical department. In the end I chose it. This department did not have a direct connection with space at that time, but it was incredibly interesting for me to study there. I liked working with the telescope and solving practical problems. After the 3rd year we went to practice in the Tien Shan. It was an amazing time! But in the 4th year my fate was decided - I ended up with the outstanding physicist Yakov Borisovich Zeldovich. At that time, neutron stars and black holes were discovered as X-ray sources in binary star systems. Zeldovich suggested that Rashid Sunyaev and I study the nature of these X-ray sources.

– A few years later, you and Sunyaev created a theory of disk accretion of matter onto black holes, for which you were awarded the State Prize of the Russian Federation this year. What is the essence of the theory?

– In double star systems, where in addition to the X-ray source, there is an ordinary optical star, it loses matter. This material falls onto a compact object, forming an accretion disk around a black hole or neutron star. Disk accretion is the process by which matter in the disk, rapidly rotating like a satellite around a gravitating center, slowly settles onto this source as momentum is lost. The accretion disk emits energy, mainly in the X-ray range of the spectrum from the inner parts of the disk close to the compact object. Rashid and I carried out the necessary calculations that confirmed our theory. The results of our research in 1973 were published in an article; there are already more than eight thousand references to it in the scientific literature.

It’s interesting that when Rashid and I made calculations in the early 70s, we knew nothing about the first X-ray satellite, Uhuru, which at the same time discovered accreting neutron stars in the X-ray range.

– Nikolai Ivanovich, what caused the increased interest of astrophysicists in the study of black holes? What does this give to humanity?

- I am often asked this question. In this regard, I remember Faraday’s experiments, how he first discovered an alternating magnetic field by moving conductors. The scientist had no idea how to use this phenomenon. But if he had not discovered an alternating magnetic field, humanity would not have known electricity for a long time!

– Is it possible to simulate a black hole under terrestrial conditions?

– It’s possible, but this is a technically incredibly difficult task. We astrophysicists prefer to study black holes in space because these objects are not to be trifled with. It is unknown what the creation of a black hole in laboratory conditions might entail. And why is this necessary? A person simply needs to raise his head from time to time and look at the sky! “Two things in the world fill my soul with sacred awe - the starry sky above my head and the moral law within us,” said the German philosopher Immanuel Kant.

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