Chemical Evolution of Heavy Elements in the Early Galaxy: Implications for Stellar Sources

TL;DR

This paper discusses the origins of heavy elements in the early Galaxy, suggesting that O-Ne-Mg core-collapse supernovae are the primary source of heavy r-process nuclei, supported by a two-component abundance model.

Contribution

It introduces a two-component model linking Fe and Eu abundances to specific supernova sources, providing a new framework for understanding heavy element origins.

Findings

O-Ne-Mg core-collapse supernovae produce heavy r-nuclei with minimal lighter elements.

A two-component model accurately predicts elemental abundances in metal-poor stars.

Observations support supernovae as key sources of heavy elements in the early Galaxy.

Abstract

An overview of the sources for heavy elements in the early Galaxy is given. It is shown that observations of abundances in metal-poor stars can be used along with a basic understanding of stellar models to guide the search for the source of the heavy r-process nuclei (r-nuclei). Observations show that this source produces very little of the elements from C through Zn including Fe. This strongly suggests that O-Ne-Mg core-collapse supernovae (SNe) from progenitors of ~8-11M_sun are the source for the heavy r-nuclei. It is shown that a two-component model based on the abundances of Fe (from Fe core-collapse SNe) and Eu (from O-Ne-Mg core-collapse SNe) gives very good quantitative predictions for the abundances of all the other elements in metal-poor stars.