Three dimensional numerical simulation of mixing in supernova explosions

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We calculate a nonlinear growth of the Rayleigh-Taylor instability in the exploding red supergiant stars with a two-dimensional hydrodynamical code, and examine how the extent of mixing depends of the progenitor's core mass and the envelope mass. The results are compared with the observations of type II-P supernovae and the recent type II-b supernova 1993J.It has been suggested that the duration of the plateau of Type II-P supernova light curves depends on the extent of inward mixing of hydrogen in the supernova ejecta. We have followed numerically a nonlinear growth of the Rayleigh-Taylor (R-T) instability in the exploding red super-giant stars with a two-dimensional (2-D) hydro-dynamical code, and examined whether or not the R-T mixing is large enough to account for the plateau length of Type II-P supernova light curves. The inward mixing of hydrogen into the core at expansion velocities of 500-800kms^<-1> is confirmed for the two red-supergiant models with the main-sequence masses o … More f 13 M_<<of sun>> and 20 M_<<of sun>>. Mixing of hydrogen is extensive enough to reproduce the plateau of light curves even with a very small amplitude of the initial perturbations such as - 0.2%. However, the outward mixing of ^<56>Ni is so defferent between the two progenitors. The nickel is mixed up to the middle of the hydrogen-rich envelope in the 13 M_<<of sun>>, while it is hardly mixed for the 20 M_<<of sun>> stars. These differences in the mixing may affect the shape of light curves.It has been suggested that the duration of the plateau of Type II-P supernova light curves depends on the extent of inward mixing of hydrogen in the supernova ejecta. We have followed numerically a nonlinear growth of the Rayleigh-Taylor (R-T) instability in the exploding red super-giant stars with a two-dimensional (2-D) hydro-dynamical code, and examined whether or not the R-T mixing is large enough to account for the plateau length of Type II-P supernova light curves. The inward mixing of hydrogen into the core at expansion velocities of 500-800kms^<-1> is confirmed for the two red-supergiant models with the main-sequence masses of 13 M_<<of sun>> and 20 M_<<of sun>>. Mixing of hydrogen is extensive enough to reproduce the plateau of light curves even with a very small amplitude of the initial perturbations such as - 0.2%. However, the outward mixing of ^<56>Ni is so defferent between the two progenitors. The nickel is mixed up to the middle of the hydrogen-rich envelope in the 13 M_<<of sun>>, while it is hardly mixed for the 20 M_<<of sun>> stars. These differences in the mixing may affect the shape of light curves. Less