China Detects Gamma-Ray Burst from Early Universe

China's Einstein Probe (EP) astronomical satellite, also known as the Tianguan satellite, has detected a gamma-ray burst originating approximately 12.5 billion light years away. This marks the first time humanity has detected soft X-ray signals from an early universe explosion, opening a new window for research into the young cosmos.

The research paper detailing this discovery was published online in the international academic journal Nature Astronomy. Gamma-ray bursts are among the universe's most violent explosions, typically generated by the explosion of massive stars. On March 15, 2024, the EP satellite captured the weak pulse signal of EP240315a in the soft X-ray band. The brightness of EP240315a fluctuated rapidly and gradually disappeared after more than 17 minutes.

Subsequently, multiple astronomical telescopes around the world observed EP240315a in succession. The research results show that it originated in the distant early universe, when the universe was just 10 percent of its current age. It took 12.5 billion years for the signal of EP240315a to reach Earth.

EP240315a stands out as unique compared to other gamma-ray bursts. Its X-ray brightness is relatively dim at the peak of the burst, and the time gap between X-rays and gamma-rays is significantly longer than other bursts. These characteristics will prompt the scientific community to re-examine the generation mechanism of gamma-ray bursts.

Experts believe that the observation results of EP240315a by the EP satellite have deepened humanity's understanding of early universe gamma-ray bursts and offer fresh insights into the origins and evolution of the universe.

The EP mission is an international collaboration effort led by the Chinese Academy of Sciences (CAS), with contributions from the European Space Agency (ESA), the Max Planck Institute for Extraterrestrial Physics (MPE) in Germany, and the French space agency CNES. Launched into space in January 2024, the satellite has achieved several initial discoveries, including an uncommon transient phenomenon, advancing understanding of the universe and extreme physical phenomena.

The EP mission aims to help scientists detect the first light from supernova explosions, search for and pinpoint X-ray signals accompanying gravitational wave events, and identify dormant black holes and other faint, transient celestial objects.