Population and spectral synthesis: it doesn't work without binaries

TL;DR

This paper emphasizes the importance of including interacting binaries in stellar population and spectral synthesis models to accurately reproduce observed properties of stellar systems and phenomena.

Contribution

It demonstrates that neglecting binaries leads to inaccuracies in spectral synthesis, highlighting the need to incorporate binary interactions for realistic modeling.

Findings

Including binaries improves modeling of the Hertzsprung-Russell diagram

Binary interactions are crucial for accurate supernova rate predictions

Spectral synthesis with binaries better reproduces ionising radiation from stellar populations

Abstract

In this chapter we discuss the population and spectral synthesis of stellar populations. We describe the method required to achieve such synthesis and discuss examples where inclusion of interacting binaries are vital to reproducing the properties of observed stellar systems. These examples include the Hertzsprung-Russell diagram, massive star number counts, core-collapse supernovae and the ionising radiation from stellar populations that power both nearby HII regions and the epoch of reionization. We finally offer some speculations on the future paths of research in spectral synthesis.