English

Stellar Yields of Rotating First Stars. II. Pair Instability Supernovae and Comparison with Observations

Solar and Stellar Astrophysics 2018-05-02 v1

Abstract

Recent theory predicts that a first star is born with a massive initial mass of \gtrsim 100 MM_\odot. Pair instability supernova (PISN) is a common fate for such a massive star. Our final goal is to prove the existence of PISN and thus the high mass nature of the initial mass function in the early universe by conducting {\it abundance profiling}, in which properties of a hypothetical first star is constrained by metal-poor star abundances. In order to determine reliable and useful abundances, we investigate the PISN nucleosynthesis taking both rotating and non-rotating progenitors for the first time. We show that the initial and CO core mass ranges for PISNe depend on the envelope structures: non-magnetic rotating models developing inflated envelopes have a lower-shifted CO mass range of \sim 70--125 MM_\odot, while non-rotating and magnetic rotating models with deflated envelopes have a range of \sim 80--135 MM_\odot. However, we find no significant difference in explosive yields from rotating and non-rotating progenitors, except for large nitrogen production in non-magnetic rotating models. Furthermore, we conduct the first systematic comparison between theoretical yields and a large sample of metal-poor star abundances. We find that the predicted low [Na/Mg] \sim 1.5-1.5 and high [Ca/Mg] \sim 0.50.5--1.31.3 abundance ratios are the most important to discriminate PISN signatures from normal metal-poor star abundances, and confirm that no currently observed metal-poor star matches with the PISN abundance. Extensive discussion on the non-detection is finally made.

Keywords

Cite

@article{arxiv.1803.06630,
  title  = {Stellar Yields of Rotating First Stars. II. Pair Instability Supernovae and Comparison with Observations},
  author = {Koh Takahashi and Takashi Yoshida and Hideyuki Umeda},
  journal= {arXiv preprint arXiv:1803.06630},
  year   = {2018}
}

Comments

Accepted for publication in ApJ