Galaxy mergers at high resolution: From elliptical galaxies to tidal dwarfs and globular clusters

TL;DR

This paper presents the highest-resolution galaxy merger simulations to date, revealing detailed substructure formation and highlighting the importance of resolution in accurately modeling elliptical galaxy remnants.

Contribution

It introduces ultra-high-resolution merger models that resolve substructures like globular clusters and cores, advancing understanding of galaxy formation processes.

Findings

High-resolution models resolve diverse substructures

Resolution impacts the predicted properties of merger remnants

Understanding galaxy formation requires sufficiently detailed simulations

Abstract

Numerical simulations of galaxy mergers are a powerful tool to study these fundamental events in the hierarchical built-up of galaxies. Recent progress have been made owing to improved modeling, increased resolution and large statistical samples. We present here the highest-resolution models of mergers performed so far. The formation of a variety of substructures ranging from kinematically decoupled cores to globular-like clusters is directly resolved. In a resolution study, we show that the large-scale structure of elliptical-like merger remnants can be affected by the resolution, and a too modest resolution may affect the numerical predictions on the properties of major merger remnants: understanding precisely which kind of event or succession of events has formed the various types of elliptical galaxies remains an open challenge.