# GABE: Galaxy Assembly with Binary Evolution

## TL;DR

GABE introduces binary star evolution into semi-analytic galaxy formation models, improving the accuracy of luminosity predictions and enabling studies of high-energy astrophysical phenomena within a cosmological framework.

## Contribution

This work is the first to incorporate binary evolution into semi-analytic galaxy formation models using the Yunnan-II stellar population synthesis model.

## Key findings

- Model slightly reduces optical/infrared luminosity in the local universe.
- Model significantly increases ultraviolet luminosity, especially in the F_UV band.
- Predicted galaxy colors are bluer, with minimal change in luminosity functions.

## Abstract

We developed a new semi-analytic galaxy formation model: Galaxy Assembly with Binary Evolution (GABE). For the first time we introduce binary evolution into semi-analytic models of galaxy formation by using Yunnan-II stellar population synthesis model, which includes various binary interactions. When implementing our galaxy formation model onto the merger trees extracted from the Millennium simulation, it can reproduce a large body of observational results. We find that in the local universe the model including binary evolution reduces the luminosity at optical and infrared wavelengths slightly, while increases the luminosity at ultraviolet wavelength significantly, especially in $F_{\rm UV}$ band. The resulting luminosity function does not change very much over SDSS optical bands and infrared band, but the predicted colors are bluer, especially when $F_{\rm UV}$ band is under consideration. The new model allows us to explore the physics of various high energy events related to the remnants of binary stars, e.g. type Ia supernovae, short gamma-ray bursts and gravitational wave events, and their relation with host galaxies in a cosmological context.