COSMIC Variance in Binary Population Synthesis

TL;DR

This paper introduces COSMIC, a fast and efficient binary population synthesis tool, to simulate and analyze the Galactic population of compact binaries and their gravitational wave signals for LISA.

Contribution

The paper presents COSMIC, a community-developed binary population synthesis suite that enables rapid simulation of large binary populations, including compact-object binaries and their gravitational wave signals.

Findings

Approximately 10^8 compact binaries in the Milky Way.

Around 10^4 binaries may be resolvable by LISA.

COSMIC effectively models binary populations for gravitational wave studies.

Abstract

The formation and evolution of binary stars is a critical component of several fields in astronomy. The most numerous sources for gravitational wave observatories are inspiraling and/or merging compact binaries, while binary stars are present in nearly every electromagnetic survey regardless of the target population. Simulations of large binary populations serve to both predict and inform observations of electromagnetic and gravitational wave sources. Binary population synthesis is a tool that balances physical modeling with simulation speed to produce large binary populations on timescales of days. We present a community-developed binary population synthesis suite: COSMIC which is designed to simulate compact-object binary populations and their progenitors. As a proof of concept, we simulate the Galactic population of compact binaries and their gravitational wave signal observable by the Laser Interferometer Space Antenna (LISA). We find that $\sim10^8$ compact binaries reside in the Milky Way today, while $\sim10^4$ of them may be resolvable by LISA.