A CORE-COLLAPSE SUPERNOVA MODEL FOR THE EXTREMELY LUMINOUS TYPE Ic SUPERNOVA 2007bi: AN ALTERNATIVE TO THE PAIR-INSTABILITY SUPERNOVA MODEL

We present a core-collapse supernova (SN) model for the extremely luminous Type Ic SN 2007bi. By performing numerical calculations of hydrodynamics, nucleosynthesis, and radiation transport, we find that SN 2007bi is consistent with the core-collapse SN explosion of a 43 M ☉ carbon and oxygen core obtained from the evolution of a progenitor star with a main-sequence mass of 100 M ☉ and metallicity of Z = Z ☉ /200, from which its hydrogen and helium envelopes are artificially stripped. The ejecta mass and the ejecta kinetic energy of the models are 40 M ☉ and 3.6 × 10 52 erg. The ejected 56 Ni mass is as large as 6.1 M ☉ , which results from the explosive nucleosynthesis with large explosion energy. We also confirm that SN 2007bi is consistent with a pair-instability SN model as has recently been claimed. We show that the earlier light-curve data can discriminate between the models for such luminous SNe.