China builds a telescope to hunt for dark matter

Chinese scientists plan to build the next space observatory to search for mysterious dark matter in the universe.

VLAST will be much more sensitive than NASA's Fermi telescope.

The Very Large Area Gamma-ray Space Telescope (VLAST) is in the early stages of research and development. But the Chinese scientists' goal is to reach 10 times the magnitude of NASA's Fermi Large Area Telescope, the world's most sensitive gamma-ray telescope today. VLAST could enter orbit by the end of the decade if it gets early approval from the Chinese government, according to the team.

Gamma rays are the form of light with the highest energy. This type of beam helps scientists observe objects such as fast-rotating neutron stars and super-dense black holes. It is also indirect evidence of dark matter, which makes up most of the matter in the universe. Astronomers think that dark matter certainly exists to provide the gravity needed to bind galaxies and galaxy clusters together. Theoretically, when dark matter particles collide, they decay or annihilate each other, simultaneously creating gamma rays that can be detected by telescopes.

To look for traces of dark matter particles, VLAST will track the gamma-ray spectrum between 0.3 giga-electron volts and 20 tera-electron volts with unprecedented resolution, according to the team's paper published today. in the journal Acta Astronomica Sinica on May 26. According to them, VLAST will also look deep into the center of the Milky Way to check for an excess of gamma-ray radiation, which could reveal the existence of self-destructing dark matter.

The paper's authors include researchers from the Purple Mountain Observatory in Nanning, the University of Science and Technology of China in Hefei, and the Institute of Modern Physics in Lanzhou. In addition to searching for dark matter, the team also plans to use VLAST to explore gamma-ray flashes, X-ray binary stars, and the origin of cosmic rays.

Based on the preliminary design, VLAST will consist of 3 detectors. Detectors will distinguish gamma-ray photons from other types of particles that reach the telescope, and then precisely measure the energy and flight path of the gamma-ray photon. As expected, the detector cluster will have a total mass of 16 tons, much heavier than conventional space telescopes and need to be put into orbit by the Long March 5 rocket, according to the lead researcher, Fan Yizhong of Taiwan Observe Purple.

Fan and his team are developing key technologies for the project, from electronics to detectors and satellite arrays. They calculate it will take at least 10 years for the telescope to be ready for operation. The team has submitted the VLAST design to the Chinese Academy of Sciences and is awaiting a decision.