# The History of Galaxy Mergers in IllustrisTNG

**Authors:** Bendeguz Koncz, Istvan Horvath, András Péter Joó, Andreas Burkert, L. Viktor Tóth  
**arXiv:** [2509.09355](https://arxiv.org/abs/2509.09355)  
**Date:** 2025-09-11  
**Summary page:** https://www.summarizepaper.com/en/paper/2509.09355v1/

## Key points

- Study titled "The History of Galaxy Mergers in IllustrisTNG" by Bendeguz Koncz, Istvan Horvath, András Péter Joó, Andreas Burkert, and L. Viktor Tóth
- Address the impact of galaxy collisions on star formation and metallicity
- Highlight the role of local environment in shaping galactic evolution during mergers
- Utilize modern simulations with enhanced capacity and incorporate cutting-edge physical knowledge alongside new observations from JWST
- Calculate key metrics such as average star formation rate (SFR) and mass across various redshifts using IllustrisTNG cosmological simulation framework
- Explore how environmental conditions influence galactic evolution during mergers by examining local density as a crucial factor
- Investigate how the SFR evolves within merging galaxies to gain deeper insights into transformative processes
- Uncover notable differences in star formation rate density (SFRD) history between theoretical models and empirical data through comparisons with JWST observations

## Summary

In their study titled "The History of Galaxy Mergers in IllustrisTNG," authors Bendeguz Koncz, Istvan Horvath, András Péter Joó, Andreas Burkert, and L. Viktor Tóth delve into the complex process of galaxy evolution over cosmic time. They address the ongoing debate surrounding the impact of galaxy collisions on star formation and metallicity. The researchers highlight the significant role that the local environment plays in shaping galactic evolution during mergers. However, detailed examination has been limited until now. To shed light on these intricate dynamics, they utilize modern simulations with enhanced capacity and incorporate cutting-edge physical knowledge alongside new observations from JWST (James Webb Space Telescope). By leveraging the IllustrisTNG cosmological simulation framework and meticulously analyzing catalogue data and merger tree files from the TNG300-1 simulation, they calculate key metrics such as the average star formation rate (SFR) and mass across various redshifts ranging from 0 to 15. A focal point of their investigation is exploring how environmental conditions influence galactic evolution during mergers by examining local density as a crucial factor. Additionally, they investigate how the SFR evolves within merging galaxies to gain deeper insights into these transformative processes. Through comparing their findings with results obtained from JWST observations, the researchers uncover notable differences in the star formation rate density (SFRD) history between theoretical models and empirical data. Overall, this comprehensive study offers valuable contributions to our understanding of galaxy mergers and their implications for cosmic evolution. The integration of advanced simulations and observational data provides a nuanced perspective on the intricate interplay between galactic interactions, star formation dynamics, and environmental influences throughout cosmic history.