spacetoday.net: Cosmic rays linked to supernovae

Cosmic rays linked to supernovae

Posted: Tue, Feb 19, 2013, 7:12 AM ET (1212 GMT)
Supernova cosmic ray illustration (SLAC)

Astronomers have found evidence suggesting that high-energy cosmic rays are produced in the shock fronts of supernova explosions. Observations by ground and space-based telescopes of supernovae indicated that their expanding shock waves can accelerate protons to close to the speed of light; most cosmic rays are such high-speed protons. Gamma-ray observations confirmed this origin by detecting gamma rays at the energies expected when an accelerated proton collides with a stationary one. Astronomers had previously speculated that supernovae were the source of cosmic rays, but lacked proof before these observations.