Shock-induced star cluster formation in colliding galaxies

TL;DR

This study uses high-resolution simulations to explore how galaxy collisions induce shock compression, leading to the formation of hierarchical star clusters with masses from 10^5 to 10^8 solar masses.

Contribution

It demonstrates the detailed process of star cluster formation during galaxy collisions using advanced simulation techniques, highlighting shock-induced gas compression and hierarchical merging.

Findings

Star clusters form in dense, cold gas filaments created by shock compression.

Star clusters range in mass from 10^5 to 10^8 solar masses.

Hierarchical merging leads to larger star clusters over time.

Abstract

We studied the formation process of star clusters using high-resolution N-body/smoothed particle hydrodynamcs simulations of colliding galaxies. The total number of particles is 1.2x10^8 for our high resolution run. The gravitational softening is 5 pc and we allow gas to cool down to \sim 10 K. During the first encounter of the collision, a giant filament consists of cold and dense gas found between the progenitors by shock compression. A vigorous starburst took place in the filament, resulting in the formation of star clusters. The mass of these star clusters ranges from 10^{5-8} Msun. These star clusters formed hierarchically: at first small star clusters formed, and then they merged via gravity, resulting in larger star clusters.