China's observatory detects gamma rays from surprising cosmic sources

China's Large High Altitude Air Shower Observatory(LHAASO) have detected a dozen sources of ultra-high-energy gamma rays. The Chinese cosmic ray observatory has found 12 sources of ultrahigh-energy photons and detected a photon with a record-breaking energy level of 1.4 peta-electron volt. Gamma rays with such high energy have never been detected before, according to the study published in the journal Nature. 

LHAASO detected 12 stable gamma ray sources with energies up to about 1 PeV and significances of the photon signals seven standard deviations greater than the surrounding background. These sources are located at positions in our galaxy that can be measured with an accuracy better than 0.3°. They are the brightest Milky Way gamma ray sources in LHAASO's field of view. Scientists led by the Institute of High Energy Physics (IHEP) under the Chinese Academy of Sciences made the discoveries after an 11-month observation period. These findings overturn the traditional understanding of the Milky Way and open up an era of UHE gamma astronomy. Cao Zhen, chief scientist of LHAASO said these observations will encourage us to explore more deeply violent celestial phenomena and their physical processes, according to the news release of LHAASO.

"These findings overturn our traditional understanding of the Milky Way and open up an era of UHE gamma astronomy. These observations will prompt us to rethink the mechanism by which high-energy particles are generated and propagated in the Milky Way", said Cao Zhen.

The findings of the first 11 months of observation have revealed that all these sources emit gamma rays above 0.1 PeV. The new discovery shows that the Milky Way is full of PeVatrons. The findings would help the scientists to find the origins of extremely high-energy cosmic rays. Yang Ruizhi, one of the corresponding authors of the paper said that these bodies include young massive star clusters, supernova remnants, pulsar wind nebulas represented by Cygnus star-forming regions and the Crab nebula.

IMAGE: AP