Matter around a black hole was first obtained in a laboratory. What does it mean?

What kind of plasma are we talking about?

Black hole accretion disks have been obtained in laboratory conditions. It's like this

structure that results from the diffusion of torque-bearing material onto a massive central body. 

Such disks also appear around stars inclose binary systems, in rotating galaxies and in protoplanetary formations. In addition, a similar substance appears in the mechanism of gamma-ray bursts that accompany the merger of neutron stars and the collapse of the cores of supernovae and hypernovae.

Compression of matter, as well as the release of heat as a result of friction of differentially rotating layers, leads to heating of the accretion disk. 

Accretion disk formation around the pulsar

How does a substance appear naturally?

We have already said that gas flowing from onecomponent of the system to another, has a significant angular momentum: it appears due to orbital motion. Therefore, gas particles cannot fall on the star radially. Instead, they move around it in Keplerian orbits.

As a result, a gas disk is formed in whichthe velocity distribution corresponds to Kepler's laws. According to it, layers located closer to the star will have higher velocities. However, due to friction between the layers of gas, their velocities are equalized, and the inner layers transfer part of their angular momentum to the outside.

As a result, the inner layers approach the star and eventually fall to its surface. In fact, the trajectories of individual gas particles are in the form of spirals that slowly twist.

Radial displacement of matter in the accretion diskaccompanied by the release of gravitational energy, part of which turns into kinetic energy (acceleration of gas movement when approaching a star), and the other part turns into heat and heats the disk matter. Therefore, the accretion disk emits thermal electromagnetic radiation. The kinetic energy of the gas upon collision with the surface of the star is also transformed into thermal energy and radiated.

How was the substance created in the laboratory?

The main property of the formation of suchX-ray sources will be strong magnetic radiation. Its magnetic field and induction can reach several thousand Tesla, researchers from the LaPlaz Institute, NRNU MEPhI and the CELIA laboratory of the University of Bordeaux note in their work.

Astrophysics has long been considered a fieldobservers, since it seemed difficult, to put it mildly, to influence the phenomena she was studying, or even more so, to reproduce them. The uniqueness of our experiment is that the parameters of the resulting plasma do not need to be scaled; they correspond to the actual parameters of the plasma in the vicinity of the black hole of close binary systems like Cygnus X-1. 

Philipp Korneev, Associate Professor, Institute of Laser and Plasma Technologies, National Research Nuclear University MEPhI

The essence of the method is the reflection effecta powerful laser beam along the spiral-shaped inner surface of the target. The target becomes a rolled piece of foil, the size of which is several hundred microns. 

The laser beam delivers 330 Joules of energyduration of one picosecond. Thus, it is almost completely absorbed in the target cavity, creating a relativistic plasma inside and a magnetic field with an induction of more than 2 thousand Tesla.

According to Kornev, due to the fact that it is so powerfulthe laser was directed at a relatively small target for 10–12 seconds, and the pulse power turned out to be approximately 20 times greater than the power consumption of the entire Earth's energy sector. 

After this, in the target volume for severalpicoseconds, matter was formed with a temperature of billions of degrees, a density of 1018 particles per cm3 and a frozen magnetic field of more than 2,000 Tesla. It is these parameters that can be detected in plasma in the active region of X-ray sources

According to the text of the study, the volume of incandescentmagnetized matter was sufficient to possess the basic characteristics of its cosmic prototype. This was also facilitated by the experimental conditions, in particular, the fact that inside the plasma volume the magnetic fields were directed towards each other in such a way that in the area of ​​contact of the opposing magnetic lines, the annihilation of the magnetic field took place, leading to the appearance of particle flows with speeds close to the speed of light.

Now what?

The experience has shown that the developedby an international group, the technique can create not only quasi-stationary magnetic fields of record magnitude, but also simulate the state of the plasma emerging in them with a high energy density of matter and electromagnetic energy. At this stage, this is in great demand in laboratory astrophysics. 

This experience, according to the international group, will becomea basis for improving the technique that creates directed particle beams: making them more efficient and powerful. Such devices are actively used in experimental science, medicine, and security systems.

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