2004ApJ...605..823B

The radio and X-ray observations of the Type Ic supernova SN 2002ap are modeled. We find that inverse Compton cooling by photospheric photons explains the observed steep radio spectrum, and also the X-ray flux observed by XMM-Newton. Thermal emission from the shock is insufficient to explain the X-ray flux. The radio-emitting region expands with a velocity of ∼70,000 km/s. From the ratio of X-ray to radio emission, we find that the energy densities of magnetic fields and relativistic electrons are close to equipartition. The mass-loss rate of the progenitor star depends on the absolute value of ε_B, and is given by M{dot}~1x10^–8(v_w/1000km/s)ε^–1_BM_☉yr^–1.