Speaker
Description
Asymptotic giant branch (AGB) stars are evolved stars born with a low mass of about 1-8M⊙, depending on their metallicity. These stars are vital to the chemical enrichment of the universe as they synthesise and eject significant amounts of carbon, nitrogen, fluorine, and about half of the material heavier than iron through the slow neutron capture process. However, one aspect often overlooked when studying the chemical contribution of low-mass stars is the influence of binary evolution. About half of low-mass stars are observed to have a stellar companion, and binary mechanisms such as mass transfer and common envelopes can alter or prevent stellar evolution onto the AGB. We use binary population synthesis to model stellar populations of single and binary low-mass stars at metallicities Z = 0.015, 0.0028, and 0.0001 to explore how binary evolution affects the formation rates of AGB stars and the consequences on the elemental yields. Overall, we find that binary evolution reduces the number of AGB stars by about 30%, limiting the ability of low-mass stars to contribute to the chemical enrichment of the universe.
