The circumstellar interaction model for the radio emission from a Type I supernova

Author:
  • RCR. A. Chevalier
    R. A. Chevalier
Publisher website
Google Scholar
Abstract
The radio emission observed from the Type I supernova Evans in M83 is interpreted in terms of the circumstellar interaction model developed for the radio emission from Type II supernovae. The model agrees with the observations in that at late times the flux has a power-law dependence on time since the explosion and the power-law index is that expected for an exploding white dwarf in a circumstellar medium. The relatively rapid evolution compared to that of Type II supernovae is attributed to a flat supernova density profile and a steep relativistic electron spectrum. The initial rise in the 6 cm flux is attributed to free-free absorption by the circumstellar wind and implies M/v (w) of about 5 x 10 to the -7th (solar mass/yr)/(km/s), where M is the wind mass loss rate and v(w) is its velocity, for a standard supernova explosion. If the supernova was a low energy event, the deduced value of M/v(w) is somewhat smaller. The implications of the model for X-ray and infrared emission are discussed. The model characteristics are most consistent with a progenitor binary system in which a massive white dwarf accretes mass from the wind of an asymptotic giant branch companion star.