The stellar origin of 7Li - Do AGB stars contribute a substantial fraction of the local Galactic lithium abundance?

TL;DR

This study evaluates various stellar sources of lithium-7 in the galaxy, concluding that asymptotic giant branch stars are less significant than previously thought, with low-mass giants and novae playing key roles.

Contribution

It provides updated lithium yields from AGB stars and revises the understanding of their contribution to galactic lithium evolution.

Findings

AGB stars are not major 7Li producers.

Low-mass giants and novae are essential for lithium enrichment.

X-ray binaries have minimal impact on 7Li evolution.

Abstract

We adopt up-to-date 7Li yields from asymptotic giant branch stars in order to study the temporal evolution of 7Li in the solar neighbourhood in the context of a revised version of the two-infall model for the chemical evolution of our galaxy. We consider several lithium stellar sources besides the asymptotic giant branch stars such as Type II supernovae, novae, low-mass giants as well as Galactic cosmic rays and low-mass X-ray binaries. We conclude that asymptotic giant branch stars cannot be considered as important 7Li producers as believed in so far and that the contribution of low-mass giants and novae is necessary to reproduce the steep rise of the 7Li abundance in disk stars as well as the meteoritic 7Li abundance. Lithium production in low-mass X-ray binaries hardly affects the temporal evolution of 7Li in the solar neighbourhood.