Science and technology reporter Lu Chengkuan.
High-energy cosmic rays come from? It's a mystery of the century. Recently, the new discovery of China's high-altitude cosmic ray observatory "Lhaaso" has brought us one step closer to solving this mystery.
On February 26, Science Bulletin officially published an important result on the origin of high-energy cosmic rays in the form of a cover article. Using the observation data of "Lasso", Chinese researchers have discovered a giant ultra-high-energy gamma-ray bubble-like structure in the formation region of the Cygnus star, and for the first time in the world, the origin of cosmic rays with an energy higher than 100 million electron volts has been found.
Institute of High Energy Physics, Chinese Academy of Sciences.
Cosmic rays are high-energy charged particles from cosmic space, mainly composed of protons and nuclei of various elements. Because it carries important scientific information such as the origin of the universe, the evolution of celestial bodies, solar activity, and the earth's space environment, the study of cosmic rays and their origins is an important way to explore the universe.
This time, in the giant ultra-high-energy gamma-ray bubble-like structure discovered by Lasso in the Cygnus star formation region, there are multiple gamma photons with an energy of more than 1,000 trillion electron volts, and the energy reaches up to 2,000 trillion electron volts.
We found that the massive star cluster located near the center of the giant ultra-high-energy gamma-ray bubble is most likely the origin of high-energy cosmic rays. *Co-corresponding author Li Cong, associate researcher at the Institute of High Energy Physics of the Chinese Academy of Sciences, said.
This cluster is made up of many stars with a surface temperature of more than 35,000 degrees Celsius and stars with a surface temperature of more than 15,000 degrees Celsius. The radiation intensity of these stars is 100 to a million times that of the Sun, and the huge radiation pressure blows the material on the surface of the stars out, forming a strong star wind that can reach speeds of thousands of kilometers per second. The collision of the star wind with the surrounding interstellar medium and the violent collision between the star wind create an extreme environment of strong shock waves and strong turbulence, which becomes a powerful particle accelerator.
*Co-corresponding author Cao Zhen, academician of the Institute of High Energy Physics of the Chinese Academy of Sciences, said that this is the first high-energy cosmic ray acceleration source that has been certified so far. With the increase of observation time, Lasso will likely detect more quadrillion-electron volts and even higher energy cosmic ray acceleration sources, which is expected to solve the mystery of the origin of cosmic rays in the Milky Way.
*:Technology**.