A joint research team made up of Chinese and Japanese scientists has discovered the highest energy cosmic gamma rays ever observed from an observatory in Tibet, opening a new window to explore the extreme universe.

The energy of the gamma rays is as high as 450 TeV, equivalent to 45 billion times of the energy of X-rays for medical diagnosis, researchers from the Institute of High Energy Physics of the Chinese Academy of Sciences said at a press conference on Wednesday.

Scientists believe that those energetic gamma rays were from the Crab Nebula, a famous supernova remnant in the constellation Taurus, about 6,500 light years away from Earth.

Previously, the highest energy ever observed for a gamma-ray photon was 75 TeV, which was detected by the HEGRA Cherenkov telescope in Germany. (Xinhua)