The Star Clusters of the Large Magellanic Cloud: Structural Parameters

TL;DR

This study analyzes the structural parameters of over a thousand stellar clusters in the Large Magellanic Cloud, fitting brightness profiles with models to understand their properties and differences from the Small Magellanic Cloud.

Contribution

It provides a comprehensive analysis of the radial luminosity profiles and structural parameters of LMC clusters, including a comparison with SMC clusters and identification of unique cluster types.

Findings

Most clusters fit standard brightness models

LMC clusters are generally smaller than SMC clusters

Presence of 'ring' clusters lacking central brightness concentration

Abstract

We present and analyze the radial luminosity profiles of a sample of 1066 stellar clusters in the Large Magellanic Cloud. By design, this study closely follows the compilation by Hill & Zaritsky of the structural parameters of stellar clusters in the Small Magellanic Cloud. Both King and Elson-Fall-Freeman (EFF) model profiles are fit to V-band surface brightness profiles measured from the Magellanic Cloud Photometric Survey images. We tabulate the concentration, central surface brightness, tidal radii, 90% enclosed luminosity radii (r_{90}), and local background luminosity density. Over two thirds of the clusters in the sample are adequately fit by one or both of these models. One notable and systematic exception, as in the SMC, are those clusters that lack a central brightness concentration, the "ring" clusters. While the bulk properties of the clusters are similar between the LMC and SMC populations, we find that the LMC lacks clusters that are as large, either in terms of core radii or r_{90}, as the largest in the SMC, perhaps a signature of larger tidal stresses in the LMC.