Particle acceleration and Tycho's supernova remnant.

Particle acceleration in shock waves may be very efficient at converting bulk kinetic energy into energy density in high-energy particles. The author investigates the implications for the dynamics and evolution of a Sedov-type blast wave, with particular reference to determining the energy of the supernova event associated with Tycho's supernova remnant. He finds that X-ray and radio observations favour a low efficiency of conversion of kinetic energy to high-energy particles, a supernova explosion energy of about 8×10⁴³J, and an ambient density of about 4 atom cm^-3.