Russian scientists have found a source of high-energy cosmic neutrinos

Russian scientists have found a source of high-energy cosmic neutrinos
Russian scientists have found a source of high-energy cosmic neutrinos
Anonim

Russian astrophysicists tracked the direction of arrival of high-energy neutrinos from space and came to an unexpected conclusion: they are all born near quasars - powerful sources of radio emission in the centers of distant active galaxies. The results of the study are published in The Astrophysical Journal.

It is believed that the centers of active galaxies - objects with a luminosity of hundreds of millions of suns - are supermassive black holes that consume the surrounding material. These active galaxies, or quasars, are clearly visible from Earth with both optical and radio telescopes.

Scientists from the Moscow Institute of Physics and Technology (MIPT), the P. N. Lebedev Physical Institute of the Russian Academy of Sciences (FIAN) and the Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS) have established that quasars serve as sources of all cosmic neutrinos with energies over a trillion electron volts (TeV).

Neutrinos are the smallest elementary particles whose mass is barely different from zero, but they can cross the Universe, practically not interacting with matter and without encountering any obstacles in their path. Trillions of neutrinos per second pass through every person on Earth, remaining completely unnoticed.

To fix the neutrino flux, the authors of the study used the IceCube under-ice neutrino detector with a volume of one cubic kilometer of ice built in Antarctica. After analyzing the data collected over seven years, the scientists initially chose the range above 200 TeV for the analysis and found that all these neutrinos were born in quasars, more precisely, in their centers, where massive black holes are located, feeding the accretion disks of distant galaxies, and also creating ultrafast very hot gas emissions.

Moreover, they found a connection between powerful bursts of radio emission in these quasars and the registration of neutrinos on the IceCube Cherenkov detector. Since neutrinos travel through the Universe at the speed of light, they come to us simultaneously with flares. Now, in their new article, the researchers argue that all high-energy neutrinos, even those with energies of tens of TeV, are generated by quasars.

"The mass production of neutrinos in quasars is now a fact that other astrophysicists have to reckon with. This is extremely important for a detailed understanding of the processes inside active galaxies that lead to the release of a huge amount of energy," the first author of the article quoted in a press release from MIPT Alexander Plavin, researcher at Moscow Institute of Physics and Technology and Lebedev Physical Institute.

"The result is surprising, since different physical conditions are required for the production of neutrinos with energies differing by a factor of a hundred or a thousand. The previously discussed mechanisms of neutrino production in active galactic nuclei worked only at high energies. results. While this is an approximate model, it is necessary to work on it, to carry out computer modeling ", - says the co-author of the discovery, chief researcher of the INR RAS, corresponding member of the Russian Academy of Sciences Sergei Troitsky.

In the near future, projects aimed at the systematic study of cosmic sources of neutrinos will start in Russia and foreign countries. In particular, in 2021, Russian scientists plan to receive the first data from the Baikal GVD underwater neutrino telescope. The authors of the study hope that new observations will confirm their hypothesis that the source of almost all neutrinos that come to Earth from space are supermassive black holes.

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