China-led team caught ray produced by the biggest explosion since the Big Bang

Scientists identify spectral line with energy levels close to the speed of light in once-in-10,000-years cosmic event

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An illustration of the supernova that launched the BOAT. Scientists identified a spectral line with energy levels peaking at 37 million electron volts (MeV) during an exceptionally powerful gamma-ray burst. Photo: Aaron M. Geller/Northwestern/ CIERA/IT Research Computing and Data Services

Published: 10:00pm, 4 Aug 2024

In the wake of what might have been the biggest cosmic explosion since the Big Bang, matter and antimatter collided at nearly the speed of light, annihilating each other and releasing their energy back into the universe, a new study from China has suggested.

By analysing data from Chinese and US space telescopes, a team led by researchers from the Chinese Academy of Sciences (CAS) identified a spectral line with energy levels peaking at 37 million electron volts (MeV) during an exceptionally powerful gamma-ray burst, now known as the Brightest Of All Time, or BOAT.

As the BOAT comprised various high-energy particles, including electrons and their antimatter counterparts, positrons, it is likely these particles underwent annihilation, released gamma-ray photons and led to the observed spectral line, they reported in the journal, Science China: Physics, Mechanics & Astronomy, last week.

“Our findings have important and unique value for studying the physical properties and production mechanisms of gamma-ray bursts,” Xiong Shaolin, the paper’s lead author from the Institute of High Energy Physics, told Chinese media on June 26.

The 37 MeV line energy is “the highest detected from any gamma-ray bursts – and any object – so far,” said Bing Zhang from the University of Nevada, Las Vegas, who is not involved in the research.

It means that the gamma-ray burst ejecta was moving at least 99.98 per cent the speed of light, he told the South China Morning Post on Tuesday.