The impact of binary star yields on the spectra of galaxies
  One of the complexities in modelling integrated spectra of stellar
populations is the effect of interacting binary stars besides type Ia
supernovae (SNeIa). These include common envelope systems, CVs, novae, and are
usually ignored in models predicting the chemistry and spectral absorption line
strengths in galaxies. In this paper predictions of chemical yields from
populations of single and binary stars are incorporated into a galactic
chemical evolution model to explore the significance of the effects of these
other binary yields. Effects on spectral line strengths from different
progenitor channels of SNeIa are also explored. Small systematic effects are
found when the yields from binaries, other than SNeIa, are included, for a
given star formation history. These effects are, at present, within the
observational uncertainties on the line strengths. More serious differences can
arise in considering different types of SNIa models, their rates and
contributions.
