Effects of Jet-like Explosion in SN 1987A

We study the effects of jet-like explosion in SN 1987A. Calculations of the explosive nucleosynthesis and the matter mixing in a jet-like explosion are performed and their results are compared with the observations of SN 1987A. It is shown that the jet-like explosion model is favored because the radioactive nuclei Ti is produced in a sufficient amount to explain the observed bolometric luminosity at 3600 days after the explosion. This is because the active alpha-rich freezeout takes place behind the strong shock wave in the polar region. It is also shown that the observed line profiles of Fe[II] are well reproduced by the jet-like explosion model. In particular, the fast moving component travelling at (3000-4000) km/s is well reproduced, which has not been reproduced by the spherical explosion models. Moreover, we conclude that the favored degree of a jet-like explosion to explain the tail of the light curve is consistent with the one favored in the calculation of the matter mixing. The concluded ratio of the velocity along to the polar axis relative to that in the equatorial plane at the Si/Fe interface is ∼ 2 : 1. This conclusion will give good constraints on the calculations of the dynamics of the collapse-driven supernova. We also found that the required amplitude for the initial velocity fluctuations as a seed of the matter mixing is ∼ 30%. This result supports that the origin of the fluctuations is the dynamics of the core collapse rather than the convection in the progenitor. The asymmetry of the observed line profiles of Fe[II] can be explained when the assumption of the equatorial symmetry of the system is removed, which can be caused by the asymmetry of the jet-like explosion with respect to the equatorial plane. In the case of SN 1987A, the jet on the north pole has to be stronger than that on the south pole in order to reproduce the observed asymmetric line profiles. Such an asymmetry may also be the origin of the pulsar kick.