The Effect of Relativistic Particle Beams on the Evolution of Supernova Envelopes: Self-Consistent Solutions

Abstract

We consider the effect of a relativistic particle beam produced as part of the collapse process of a supernova core into a neutron star or black hole on the evolution of the expanding envelope. Relativistic bremsstrahlung is the dominant energy loss mechanism until the material through which the beam propagates becomes ionized. After an ionized channel is formed, plasma processes and inverse Compton losses become the dominant loss mechanisms. The energy loss processes associated with the beam impart significant momentum to the irradiated segments of the shell. This suggests a natural explanation for the asymmetric expansion of some supernovae, including SN1987a, and may account for the early mixing seen in that object. It also implies that some fraction of the X-ray light from very early in a supernova explosion originates in an inverse Compton emission process wherein relativistic electrons from the beam collide with optical photons from the expanding envelope. In this paper we present self-consistent solutions to the rate equations for the energy loss due to collective processes and calculate the momentum transferred to the envelope by the beam. We then comment on the expected X-ray emission from SNl987a using such a model (Beall 1979), and make estimates of the associated γ-ray flux.