Dynamical Evolution of Substructured Star Clusters at 3 kpc from the Galactic Center

TL;DR

This study models the evolution of fractal star clusters near the Galactic Center, showing how substructures can survive tidal forces and evolve into objects resembling red supergiant clusters within 16 million years.

Contribution

It demonstrates the dynamical evolution of substructured star clusters in a galactic tidal field, highlighting conditions for their survival and transformation into RSGC-like objects.

Findings

Substructures can survive tidal forces under certain initial conditions.

Surviving subclusters are weakly mass segregated with a top-heavy mass function.

Single substructured clusters can evolve into multiple star clusters.

Abstract

We investigate the evolution of initial fractal clusters at 3 kpc from the Galactic Center (GC) of the Milky Way and show how red supergiant clusters (RSGCs)-like objects, which are considered to be the result of active star formation in the Scutum complex, can form by 16 Myr. We find that initial tidal filling and tidal over-filling fractals are shredded by the tidal force, but some substructures can survive as individual subclusters, especially when the initial virial ratio is $\leq$0.5.These surviving subclusters are weakly mass segregated and show a top-heavy mass function. This implies the possibility that a single substructured star cluster can evolve into multiple `star clusters'.