Russian Scientists Have Found Where Neutrinos Are Born In Space
Russian astrophysicists first identified the source of the smallest cosmic particles, neutrinos. It turned out that high-energy neutrinos are born near black holes in the centers of distant active galaxies. The results of the study are published in the Astrophysical Journal.
Neutrinos are one of the most mysterious elementary particles. Even their mass scientists still do not know, it is so small. Neutrinos freely penetrate objects, people, and even our planet.
Physicists have learned to successfully detect high-energy neutrinos coming to us from space in their interactions with the targets of neutrino detectors, but where cosmic neutrinos are born was unknown until recently. The sources of cosmic neutrinos were mainly searched for in gamma rays since it was believed that these particles should be born together with gamma radiation.
Russian scientists compared data from the IceCube neutrino telescope in Antarctica with radio astronomic observations of quasars, active nuclei of distant galaxies, and found a link between the birth of cosmic neutrinos and quasar flares.
According to scientists, supermassive black holes are located in the centers of such galaxies, absorbing the surrounding matter. During the fall of matter on a black hole, part of the particle stream is thrown back, accelerated, and gives birth to neutrinos, which then fly at the speed of light across the Universe.
High-energy neutrinos can only be produced by protons that have accelerated almost to the speed of light. The IceCube neutrino Observatory has been registering cosmic neutrinos since 2010 and measuring their energies and arrival directions.
After analyzing the origin of ultra-high-energy neutrinos, more than 200 trillion electron volts, the authors found that the directions from which ultra-high-energy neutrinos come to Earth indicate bright quasars according to the network of radio telescopes around the world.
To test their hypothesis, the scientists used data from the Russian radio astronomy telescope RATAN-600, located in the North Caucasus in Karachay-Cherkessia. In total, they analyzed about fifty high-energy neutrinos registered by IceCube.
The results confirmed that ultra-high-energy cosmic neutrinos are formed in the centers of quasars with massive black holes, accretion disks, and very hot gas emissions.
"Before us, scientists were looking for a source of high-energy neutrinos, which is called "under the light". We decided to test a non-standard idea, not really counting on success. But we were lucky! Long-term joint monitoring at the international arrays of radio telescopes and wonderful Russian RATAN allowed obtaining this interesting result," — presented in a press release INR RAS the words of one of the researchers Yuri Kovalev from the LPI and MIPT.
"At first I thought “too good,” but after detailed analysis and numerous tests, we confirmed a clear link neutrino events with radio emission, which is then checked for long-term measurements of flares of radiation at the radio telescope RATAN-600 of the Special Astrophysical Observatory, says another of the authors Sergey Troitsky. This is a great success in neutrino astrophysics, and now our discovery requires a theoretical explanation."
Scientists are going to test their results using the Baikal neutrino telescope Baikal-GVD, which is currently being completed at the bottom of lake Baikal and has already started a data set.