Acceleration of particles in space: a universal mechanism?
L.I. Miroshnichenkob,a aLomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Leninskie Gory 1 build. 2, Moscow, 119991, Russian Federation bPushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Kaluzhskoe shosse 4, Troitsk, Москва, 108840, Russian Federation
Experimental evidence for and against the existence of a universal mechanism for the acceleration of charged particles in the Universe is analyzed from modern positions. We have implemented a purely phenomenological approach to this very complex problem. Consideration is carried out for various scales of space, ranging from the magnetospheres of the Earth and other planets of the solar system to the atmosphere of the Sun, the heliosphere, supernova explosions and extragalactic objects responsible for the generation of cosmic rays of extremely high energies. It is shown that there is a wide variety of acceleration mechanisms in the Universe. However, the data obtained in the course of numerous experiments on the nuclear composition of accelerated particles may testify in favor of the global character of the stochastic acceleration mechanism of the Fermi type, which is inherent in various astrophysical objects. It cannot be ruled out that this mechanism may be dominant among others. Nevertheless, a number of experimental observations do not fit into the framework of this conclusion. It is possible that in a number of space objects there is a hierarchy of accelerating mechanisms, when, after preliminary acceleration by one mechanism, others are switched on — sequentially or on an alternative basis. In this regard, we consider all available modern data "pro et contra" of the global "presence" of a Fermi-type mechanism.
Keywords: cosmic rays, sources and mechanisms of acceleration, shock waves in space, plasma physics, spectrum, composition, anisotropy, new physics of nuclear interactions DOI:10.3367/UFNe.2021.07.039022 Citation: Panasyuk M I, Miroshnichenko L I "Acceleration of particles in space: a universal mechanism?" Phys. Usp., accepted
Received: 5th, November 2020, revised: 14th, July 2021, accepted: 17th, July 2021