The presence of a galactic component in the flux of high-energy astrophysical neutrinos that was recorded by the IceCube detector over the course of 9 years of observations has been confirmed by Russian astronomers. About 28 percent of the total flow of astrophysical neutrinos have energy that are more than 200 teraelectronvolts, and that flux is accounted for by galactic neutrinos. The article was published in the letter section of The Astrophysical Journal.
During the disintegration of mesons or the interaction of cosmic rays with atomic nuclei and photons, astrophysical neutrinos with energy ranging from a few teraelectronvolts to several teraelectronvolts can be created. These neutrinos have the ability to penetrate atomic nuclei. In spite of numerous recordings, establishing the source of these neutrinos remains a challenging endeavor. This is primarily owing to the fact that the effect of the Earth’s atmosphere and the lack of adequate angular resolution of ground-based neutrino detectors make the process tough. It is generally accepted the flow of astrophysical neutrinos detected on Earth does not come from a single source class, but rather comes from both galactic and extragalactic sources, such as blazars, which are active nuclei of galaxies that contain supermassive black holes. On the other hand, it has not yet been demonstrated beyond a reasonable doubt that galactic neutrinos exist.
A team of Russian astronomers from the ACS PhIAN, lead by Yuri Kovalev, came to the conclusion that they needed to find out whether or not galactic neutrinos are present among the astrophysical neutrinos that have been detected to have the highest energy. In order to accomplish this, the researchers used a sample of 70 registration events of neutrinos with energies above 200 teraelectronvolts detected by the IceCube detector located in Antarctica between the years 2009 and 2018, and then analyzed the distribution of directions of arrival of these neutrinos based on the galactic latitude.
An anisotropic component of the neutrino flux was found by researchers, and their findings had a statistical significance of 4.1 sigma. This component was found to be emanating from a location of the low Galactic latitude. At the energies under consideration, it is responsible for around 28 percent of the total neutrino flux in astrophysical phenomena. The interaction of cosmic rays with the diffuse matter and radiation in the Milky Way is thought to be the source of at least some of the galactic high-energy neutrinos. To gain a deeper understanding of the nature of neutrinos, additional observational data must be gathered from detectors.