摘要

SN 2007bi is an extremely luminous Type Ic supernova. This supernova is thought to be evolved from a very massive star, and two possibilities have been proposed for the explosion mechanism. One possibility is a pair-instability supernova with an M-CO similar to 100 M CO core progenitor. Another possibility is a core-collapse supernova with M-CO similar to 40 M-circle dot. We investigate the evolution of very massive stars with main-sequence mass M-MS = 100-500 M-circle dot and Z(0) = 0.004, which is in the metallicity range of the host galaxy of SN 2007bi, to constrain the progenitor of SN 2007bi. The supernova type relating to the surface He abundance is also discussed. The main-sequence mass of the progenitor exploding as a pair-instability supernova could be M-MS similar to 515-575 M-circle dot. The minimum main-sequence mass could be 310 M-circle dot when uncertainties in the mass-loss rate are considered. A star with M-MS similar to 110-280M(circle dot) evolves to a CO star, appropriate for the core-collapse supernova of SN 2007bi. Arguments based on the probability of pair-instability and core-collapse supernovae favour the hypothesis that SN 2007bi originated from a core-collapse supernova event.

  • 出版日期2011-3