Explosive nucleosynthesis in massive Pop III stars and abundances in metal-poor stars and M87

Abstract

In order to understand the elemental abundance pattern observed in galaxies and clusters of galaxies of various metallicity, we investigate stability, evolution and explosion of massive population III stars. We find the upper limit mass of the pulsationally stable Pop III ZAMS stars is similar to 130M(circle dot), and the mass loss rate of unstable stars may be low. The nucleosynthesis results are compared with abundances of metal-poor halo stars arid intragalactic medium around M87. We suggest that stars with enhanced [(Zn, V, Co, Ca, Si)/Fe] may be significantly contaminated by hypernova products rather than normal supernovae. It is also noticed that hypernovae can be important sources for high Si/O and S/O ratio observed in M87.