Astronomers discovered a new source of high-energy gamma radiation LHAASO J2108 + 5157 according to the rain-caused particles in the Earth’s atmosphere. The opening is reported in the article published in the repository of preprints ARXIV.
Sources emitting gamma radiation with photon energy from 100 gigaelectronvolt (GeV) up to 100 teraelectronvolt (TEV) are called very high energy gamma radiation sources (VHE), and sources with photon energy above 0.1 PEELEGTROLONVOLT (PEV) Known as sources of ultra-high energy gamma radiation (UHE). The nature of these sources is not fully studied, so astronomers are constantly looking for objects of this type in order to characterize them and reveal the mysterious mechanisms that generate radiation.
The new search for sources of gamma radiation sources was carried out using a LHAASO – a high-altitude observatory, observing atmospheric lines from secondary subatomatic particles, formed as a result of a collision of high-energy cosmic rays with an earthly atmosphere. The researchers observed a significant excess of shower induced by gamma radiation in the energy range of 25-100 TEV and more than 100 TEV. According to scientists, this is the first source discovered in the range of ultra-high energies, which is not accompanied by a very high energy radiation.
LHAASO J2108 + 5157 is a source with a length of less than 0.39 degrees. Although it is possible that the source is point, and its extended morphology is simply the result of limited data. There are no x-ray sources near it with the exception of the elastic dual system RX J2107.3 + 5202, which is removed on the angular distance of 0.3 degrees. It is shown that LHAASO J2108 + 5157 is associated with a molecular cloud known as [MML2017] 4607. The cloud is located at a distance of about 10,700 light years from the Earth and contains 8469 solar masses.
As noted by astrophysics, ultra-high energy radiation can be caused by high-energy protons, when they face the surrounding dense gas in the molecular cloud. Gamma rays occur during the decay of π0-mesons, resulting from inelastic clashes between accelerated protons and gas molecules.