TITLE: "Supernova Remnant Shock Waves: Nature's Particle Accelerators."

SPEAKER: Professor Stephen P. Reynolds,

Supernovae eject approximately 10⁵¹ ergs into the interstellar medium, in kinetic energy of several solar masses of material moving at speeds up to several percent of the speed of light. These explosions drive shock waves that take 10,000 to 100,000 years to slow down to subsonic speeds. I shall describe the evidence that these shock waves not only heat the shocked gas to 10⁷ K or above, but also accelerate a small fraction of particles to fantastically high energies, up to 100 TeV or above, confirming our long-held suspicions that supernova remnants are the sources of the bulk of the cosmic rays observed at Earth. Recent evidence comes in the form of analysis of supernova-remnant X-ray emission; some of that emission appears to be due to synchrotron radiation from electrons with energies of order 100 TeV gyrating in 10 microgauss magnetic fields.