Source: Xinhua News Agency
reporter learned from the dark matter satellite "Wukong" team on the 1st that based on the " Wukong " data, scientific researchers recently drew the highest boron/carbon, boron/oxygen cosmic ray particle ratio energy spectrum to date, and discovered a new structure of the energy spectrum. This latest achievement shows that high-energy particles in the universe may propagate more slowly than expected.
Cosmic rays are high-energy particles from outer space. Among them, carbon and oxygen nuclei are the primary particles produced during the synthesis of stellar nuclei, while boron nucleus is mainly secondary particles produced after the collision with interstellar matter during the propagation process. In the observations in the first six years, "Wukong" recorded more than 3.5 million carbon, oxygen and boron nuclei data, and based on this, researchers accurately drew the precise energy spectrum of the boron/carbon ratio and boron/oxygen ratio of cosmic rays of 0.01TeV/n to 5.6TeV/n (1TeV/n = 1 trillion electron volts /nucleon) energy segment. At about 0.1 TeV/n, the energy spectrum showed a turning point that was significantly different from the theoretical expectations.
chief scientist of dark matter satellite and academician of Chinese Academy of Sciences Chang Jin introduced that this is the first time that "Wukong" has accurately measured the ratio of secondary/primary particles in cosmic rays. In the energy segment above 1TeV/n, "Wukong" draws the highest energy spectrum accuracy and "sees" an energy spectrum structure different from the expected one, which means that the classic cosmic ray propagation model may need further correction. Yue Chuan, a member of the satellite science team and associate researcher at the Purple Mountain Observatory of the Chinese Academy of Sciences, explained that the boron/carbon and boron/oxygen ratio in the high-energy segment may be because the spread of high-energy particles in the universe is slower than expected. The slower the primary particles propagate, the more chances there are to collide with interstellar matter, and then break down to produce more secondary particles.
"Because the collision products of cosmic ray particles will form the background for dark matter detection, this study may also help humans find dark matter more accurately," said Yue Chuan.
"Wukong" is my country's first astronomical satellite and was launched at the end of 2015. At present, the satellite probe is still in good condition and various scientific data are also accumulating.
"Wukong" scientific research team disclosed that the team is currently carrying out key technical research on the next generation dark matter detection project "Very large-area gamma-ray space telescope (VLAST). The next-generation space telescope's ability to detect gamma rays will be increased by more than 50 times, which may help humans track specific traces of dark matter and can also efficiently study the changes in cosmic celestial bodies.
This research results have been recently published in the comprehensive academic journal " Science Bulletin " (English version).
