E-Mail IMAGE: Gamma-ray image above 10 TeV around SNR G106.3+2.7 as seen by the Tibet ASgamma experiment. PSF shows smearing by the angular resolution. Black/cyan contours represent the SNR shell and the... view more Credit: Image by IHEP The Tibet ASgamma experiment, a China-Japan joint research project, has discovered gamma rays beyond 100 TeV (tera electron volts) from G106.3+2.7, a supernova remnant (SNR) 2600 lightyears from Earth. These gamma rays are of the highest energy ever observed from SNRs, and are probably produced in collisions between cosmic rays (protons) accelerated in G106.3+2.7 and a nearby molecular cloud. "SNR G106.3+2.7 is thus the first candidate object with sufficient evidence in the Milky Way that can accelerate cosmic rays (protons) up to 1 PeV (peta electron volts)," said HUANG Jing, one of the leading researchers of the study from the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences. "It will open an important window in the search for the 'PeVatron'," she said.