Abundance profiling of extremely metal-poor stars and supernova properties in the early universe

Tominaga, Nozomu*; Iwamoto, Nobuyuki  ; Nomoto, Kenichi*

The first metal enrichment in the universe was made by a supernova (SN) explosion of a population (Pop) III star and chemical evolution of the universe is recorded in abundance patterns of extremely metal-poor (EMP) stars. Increasing number of the EMP stars is now being discovered. This allows us to statistically constrain properties of SNe of Pop III stars (Pop III SNe). We investigate the properties of Pop III SNe by comparing their nucleosynthetic yields with the abundance patterns of the EMP stars. We focus on the most metal-poor stars with [Fe/H] 3.5 and present Pop III SN models that reproduce well their individual abundance patterns. From these models we derive relations between abundance ratios and properties of Pop III SNe: [(C+N)/Fe] vs. an ejected Fe mass, and [(C+N)/Mg] vs. a remnant mass. Using fitting functions, distribution of the abundance ratios of EMP stars is converted to those of the properties of Pop III SNe, which can be compared with SNe in the present day.