Pair-Instability Supernovae of Fast Rotating Stars

Abstract

We present 2D simulations of pair-instability supernovae considering rapid rotation during their explosion phases. Recent studies of the Pop III star formation suggested that these stars could be born with a mass scale about 100 Msun and with a strong rotation. Based on stellar evolution models, these massive Pop III stars might have died as highly energetic pair-instability supernovae. We perform 2D calculations to investigate the impact of rotation on pair-instability supernovae. Our results suggest that rotation leads to an aspherical explosion due to an anisotropic collapse. If the first stars have a 50% of keplerian rotational rate of the oxygen core before their pair-instability explosions, the overall Ni production can be significantly reduced by about two orders of magnitude. An extreme case of 100% keplerian rotational rate shows an interesting feature of fluid instabilities along the equatorial plane caused by non-synchronized and non-isotropic ignitions of explosions, so that the shocks run into the in-falling gas and generate the Richtmyer--Meshkov instability.