Topological data analysis reveals differences between simulated galaxies and dark matter haloes

TL;DR

This study employs topological summaries based on Betti curves to compare the spatial distributions of simulated galaxies and dark matter haloes, revealing significant differences and dependencies on galaxy type and feedback processes.

Contribution

It introduces the use of Betti curve-based topological summaries to distinguish between galaxy and dark matter distributions and their dependence on feedback mechanisms.

Findings

Galaxy and dark matter distributions have significantly different topologies.

Star-forming and quiescent galaxies show distinct topological patterns.

Topology of quiescent galaxies depends strongly on supernova feedback.

Abstract

We use topological summaries based on Betti curves to characterize the large-scale spatial distribution of simulated dark matter haloes and galaxies. Using the IllustrisTNG and CAMELS-SAM simulations, we show that the topology of the galaxy distribution is significantly different from the topology of the dark matter halo distribution. Further, there are significant differences between the distributions of star-forming and quiescent galaxies. These topological differences are broadly consistent across all simulations, while at the same time there are noticeable differences when comparing between different models. Finally, using the CAMELS-SAM simulations, we show that the topology of the quiescent galaxies in particular depends strongly on the amount of supernova feedback. These results suggest that topological summary statistics could be used to help better understand the processes of galaxy formation and evolution.