Supernova nucleosynthesis in population III 13-50 m☉ stars and abundance patterns of extremely metal-poor stars.
TOMINAGA N., UMEDA H. and NOMOTO K.
Abstract (from CDS):
We perform hydrodynamic and nucleosynthesis calculations of core-collapse supernovae (SNe) and hypernovae (HNe) of Population (Pop) III stars. We provide new yields for the main-sequence mass of MMS=13-50 M☉ and the explosion energy of E=1-40x1051 ergs to apply to chemical evolution studies. Our HN yields based on the mixing-fallback model of explosions reproduce the observed abundance patterns of extremely metal-poor (EMP) stars (-4<[Fe/H]←3), while those of very metal-poor (VMP) stars (-3<[Fe/H]←2) are reproduced by the normal SN yields integrated over the Salpeter initial mass function. Moreover, the observed trends of abundance ratios [X/Fe] against [Fe/H] with small dispersions for the EMP stars can be reproduced as a sequence resulting from the various combination of MMS and E. This is because we adopt the empirical relation that a larger amount of Fe is ejected by more massive HNe. Our results imply that the observed trends with small dispersions do not necessarily mean the rapid homogeneous mixing in the early Galactic halo at [Fe/H]←3 but can be reproduced by the ``inhomogeneous'' chemical evolution model. In addition, we examine how the modifications of the distributions of the electron mole fraction Ye and the density in the presupernova models improve the agreement with observations. In this connection, we discuss possible contributions of nucleosynthesis in the neutrino-driven wind and the accretion disk.
Galaxy: Halo - Nuclear Reactions, Nucleosynthesis, Abundances - Stars: Abundances - Stars: Population II - Stars: Supernovae: General