A Progenitor for the Extremely Luminous Type Ic Supernova 2007bi

TL;DR

This study investigates the progenitor of the extremely luminous Type Ic supernova 2007bi, analyzing massive star evolution to determine whether it originated from a pair-instability or core-collapse supernova, with evidence favoring the latter.

Contribution

It provides detailed stellar evolution models for very massive stars to constrain the progenitor type of SN 2007bi, favoring core-collapse over pair-instability origins.

Findings

Progenitor likely a 110-280 M_sun star evolving into a CO core.

Main-sequence mass for pair-instability progenitor estimated at 515-575 M_sun.

Probability analysis favors core-collapse supernova origin.

Abstract

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} ~ 100 M_sun CO core progenitor. Another possibility is a core-collapse supernova with M_{CO} ~ 40 M_sun. We investigate the evolution of very massive stars with main-sequence mass M_{MS} = 100 - 500 M_sun 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} ~ 515 - 575 M_sun. The minimum main-sequence mass could be 310 M_sun when uncertainties in the mass-loss rate are considered. A star with M_{MS} ~ 110 - 280 M_sun 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.