Nucleosynthesis contribution of neutrino-dominated accretion flows to the solar neighborhood

TL;DR

This study investigates how neutrino-dominated accretion flows (NDAFs) contribute to the chemical enrichment of the solar neighborhood, improving models of metallicity evolution and matching observed stellar abundance patterns.

Contribution

It introduces the nucleosynthesis role of NDAFs in galactic chemical evolution models, enhancing agreement with observed metallicity distributions and abundance ratios.

Findings

NDAFs increase the [Fe/H] ratio before SNe Ia onset.

Including NDAFs improves the match with observed metallicity distribution.

The model reproduces the observed [Mg/Fe] evolution at low metallicity.

Abstract

The elemental abundances of stars reflect the complex enrichment history of the galaxy. To explore and explain the metal enrichment history of the cosmic environment near our solar system, we study the evolution of $^{56} \mathrm{Fe}$ abundance over time and [Mg/Fe] versus [Fe/H] evolution in the solar neighborhood. Core-collapse supernovae make the dominant contribution in the early stages, while Type Ia supernovae (SNe Ia) have a delayed and dominant impact in the later stages. In this work, we consider the nucleosynthesis contribution of neutrino-dominated accretion flows (NDAFs) formed at the end of the lives of massive stars. The results show that the [Fe/H] gradually increases over time and eventually reaches $\rm [Fe/H]=0$ and above, reproducing the chemical enrichment process in the solar neighborhood. Before the onset of SNe Ia, the ratio of $^{56} \mathrm{Fe}$ mass to the total gas mass increases by a factor of at most $\sim 1.44$ when NDAFs are taken into account. We find that by including NDAF in our models, the agreement with the observed metallicity distribution of metal-poor stars in the solar neighborhood ($\rm < 1~kpc$) is improved, while not significantly altering the location of the metallicity peak. This inclusion can also reproduce the observed evolutionary change of [Mg/Fe] at [Fe/H] $\sim -1.22$, bringing the ratio to match the solar abundance. Our results provide an extensive understanding of metallicity evolution in the solar environments by highlighting the nucleosynthesis contribution of NDAF outflows in the solar neighborhood.