Astronomers were the first to determine the number of protons and electrons in cosmic rays from a supernova remnant.
At least 70% of the very high energy gamma rays that emit cosmic rays are due to relativistic protons, the authors of the new work found out based on the analysis of images of radio, X-ray and gamma radiation.
The place of acceleration of protons, the main components of cosmic rays, remained a mystery for a hundred years. The authors of the new work quantitatively showed how many cosmic rays are formed in the supernova remnant: this will help to clarify their origin.
The source of cosmic rays, or the highest energy particles in the universe, has been a mystery since their discovery in 1912. Cosmic rays contribute to the chemical evolution of interstellar matter, so how they are formed is important for understanding the evolution of our Galaxy.
It is believed that cosmic rays are accelerated by supernova remnants in our galaxy and reach Earth at almost the speed of light. Recent observation of gamma rays has shown that many supernova remnants emit teraelectron-volt (TeV) gamma rays.
If gamma rays are produced by protons, which are the main component of cosmic rays, then the origin of cosmic ray supernova remnants can be found out. However, gamma rays are also produced by electrons, so it is necessary to determine if the dominant origin is proton or electronic.
The results of the study confirm that gamma rays come from the proton component, which is the basis of cosmic rays, and the authors found that galactic cosmic rays are formed from supernova remnants.