Stellar multiplicity in the Milky Way Galaxy

TL;DR

This paper models the impact of binary stars on high-resolution spectroscopic surveys of the Milky Way, aiming to quantify binary detection, contamination, and population characteristics.

Contribution

It introduces a rapid binary-evolution model to simulate binary populations and analyze their effects on spectroscopic survey data.

Findings

Tentative evidence for binary fraction variation with metallicity

Binary systems can significantly affect chemical abundance measurements

The model helps constrain binary star populations in the Galaxy

Abstract

We present our models of the effect of binaries on high-resolution spectroscopic surveys. We want to determine how many binary stars will be observed, whether unresolved binaries will contaminate measurements of chemical abundances, and how we can use spectroscopic surveys to better constrain the population of binary stars in the Galaxy. Using a rapid binary-evolution algorithm that enables modelling of the most complex binary systems we generate a series of large binary populations in the Galactic disc and evaluate the results. As a first application we use our model to study the binary fraction in APOGEE giants. We find tentative evidence for a change in binary fraction with metallicity.