Binary stellar evolution yields in galactic chemical evolution calculations

TL;DR

This paper develops a framework for calculating stellar yields in galactic chemical evolution, emphasizing the importance of binary star interactions and their impact on elemental abundances.

Contribution

It introduces a comprehensive method to incorporate binary star effects into stellar yields, highlighting the dominant role of binary fraction in chemical evolution predictions.

Findings

Binary fraction significantly affects effective stellar yields.

Varying accretion efficiencies has minor impact on yields.

Binary fraction influences elemental abundance ratios, especially for lower-mass primaries.

Abstract

We present a framework for the computation of effective stellar yields that accounts for a mixed population of binary and single stars under an adjustable mix of binary evolution settings: the binary fraction, the accretion efficiencies of winds, Roche-lobe overflow, and supernovae. We emphasise the critical need for more complete yield coverage of the binary nucleosynthesis and evolution, without which the ability to make accurate predictions on the true role of binarity on GCE calculations is hamstrung. We also provide clear guidelines for future stellar modelling works to ensure their results are maximally useful to the wider community. We compute effective stellar yields using detailed binary stellar yields accounting for binary induced mass-loss from a solar-metallicity donor star. We study the effect of varying the binary mixture and accretion efficiencies, and consider a range of models for the treatment of accreted material on the secondary in detail. In the absence of detailed binary yields for the secondary, we put forth a model for the composition of accreted material that preserves the signature of the primary's nuclear processing within the post-mass-transfer secondary yields. Among the binary parameters, we find that the binary fraction, which determines the ratio of binary and single star systems, has the most significant effect on the effective stellar yields, with widespread impact across most isotopes. In contrast, varying the accretion efficiencies produces comparatively minor changes. We also find that the binary fraction has a significant influence on the logarithmic elemental abundance ratios relative to H present in the effective yield; this impact is largest for the lower-mass primaries.