China News Agency, Beijing, May 12th (Reporter Ma Haiyan) Professor Feng Hua's research team at the Department of Astronomy at Tsinghua University and collaborators completed the "Aurora Project" in the space astronomy project "Aurora Project". The X-ray polarization detector equipped with it has undergone 1 year of observation on the satellite and detected soft X-ray polarization signals from the Crab Nebula and pulsars (a type of neutron star), and for the first time discovered the mutation and recovery process of pulsar rotation Changes in the X-ray polarization signal.
This detection result also marks the reopening of the astronomical soft X-ray polarization detection window that has been stalled for more than 40 years due to technical difficulties. The latest issue of "Nature · Astronomy" magazine published this result on the evening of the 11th Beijing time.
In 1968, American scientists first carried out astronomical X-ray polarization detection, and completed the first accurate measurement on the OSO-8 satellite launched in 1975. However, due to the limitations of the previous generation technology and its low detection efficiency and sensitivity, astronomical X-ray polarization detection has stalled after this experiment.
In 2009, based on international cooperation, Feng Hua led the team to start exploring and improving X-ray polarization detection technology, and developed an X-ray polarimeter with high sensitivity and low system error. On October 29, 2018, the "Aurora Project" detector launched into space. After one year of observation, it detected the X-ray polarized signal from the Crab Nebula and discovered a new astrophysics phenomenon related to pulsars. After the rotation period of the Crab Nebula pulsar suddenly changed, its X-ray polarization also changed significantly.
It is reported that the technology adopted by the "Aurora Project" will be applied to China's next-generation large scientific project "Enhanced X-ray Time Variation and Polarization Observatory (eXTP)". eXTP is a large-scale Sino-European cooperation project led by China and is expected to be launched in 2027.
Zhang Shuangnan, chief scientist of eXTP and director of the Center for Particle Astrophysics at the Institute of High Energy, Chinese Academy of Sciences, said that the "Aurora Project" has developed the most advanced X-ray polarization measurement technology and achieved the second astronomical X-ray polarization measurement. This not only verifies the correctness of the first measurement results more than 40 years ago, but it is also very likely to discover a new phenomenon of great scientific value, which helps to understand the internal structure of neutron stars and how changes in rotation affect their external magnetic fields. The success of the "Aurora Project" shows that the scientific potential of the X-ray polarization measurement space project currently under development and planning is huge. (Finish)