Formation of the Three-Ring Structure Around Supernova 1987A

摘要

From a magnetohydrodynamic simulation, we reproduce a three-ring struc- ture in the circumstellar space of the supernova (SN) 1987A observed by the Hubble Space Telescope. When astar develops form a red supergiant (RSG) To a blue supergiant (BSG) just before the SN explosion, a wind-wind Interaction occurs between the slow stellar wind form the RSG and the Subsequent fast stellar wind form the BSG. This process is simulated nu- Merically under an assumption that the density and velocity distributions Around the RSG are anisotropic owing to the existence of toroidal magnetic Field and coronal holes. The three rings with observed size and position are Reproduced by the magnetic pinch effect and amplification of initial density Asymmetry through the dynamical interaction.