How Universal are the Young Cluster Sequences? - the Cases of LMC, SMC, M83 and the Antennae

TL;DR

This study explores whether the two distinct young cluster sequences observed in the Milky Way are also present in nearby galaxies like LMC, SMC, M83, and the Antennae, revealing similarities and differences in cluster properties.

Contribution

It extends the analysis of young cluster sequences from the Milky Way to extragalactic systems, highlighting potential similarities and differences in cluster density and expansion.

Findings

Extragalactic clusters show similar overall density scaling trends to Galactic clusters.

LMC and SMC clusters tend to have lower densities and smaller core radii.

M83 and Antennae clusters may have core radii comparable to Galactic clusters, but expansion speeds are uncertain.

Abstract

Aims.Recently a new analysis of cluster observations in the Milky Way found evidence that clustered star formation may work under tight constraints with respect to cluster size and density, implying the presence of just two sequences of young massive cluster. These two types of clusters each expand at different rates with cluster age. Methods. Here we investigate whether similar sequences exist in other nearby galaxies. Results:We find that while for the extragalactic young stellar clusters the overall trend in the cluster-density scaling is quite comparable to the relation obtained for Galactic clusters, there are also possible difference. For the LMC and SMC clusters the densities are below the Galactic data points and/or the core radii are smaller than those of data points with comparable density. For M83 and the Antenna clusters the core radii are possibly comparable to the Galactic clusters but it is not clear whether they exhibit similar expansion speeds. These findings should serve as an incentive to perform more systematic observations and analysis to answer the question of a possible similarity between young galactic and extragalactic star clusters sequences.