The low-mass stellar mass functions of rich, compact clusters in the Large Magellanic Cloud

TL;DR

This study uses Hubble Space Telescope data to analyze the stellar mass functions of six rich, compact clusters in the Large Magellanic Cloud, providing insights into their initial mass functions and comparing them to the solar neighborhood.

Contribution

It offers the first detailed derivation of present-day low-mass stellar mass functions in LMC clusters, constraining their initial mass functions and assessing environmental effects.

Findings

MF below 1.0 Msun consistent with solar neighborhood IMF

Dynamical evolution minimally affects low-mass stars in these clusters

IMF in LMC clusters similar to that in the solar neighborhood

Abstract

Context. We use Hubble Space Telescope photometry of six rich, compact star clusters in the Large Magellanic Cloud (LMC), with ages ranging from 0.01 to 1.0 Gyr, to derive the clusters' stellar mass functions (MFs) at their half-mass radii. Aims. The LMC is an ideal environment to study stellar MFs, because it contains a large population of compact clusters at different evolutionary stages. We aim to obtain constraints on the initial MFs (IMFs) of our sample clusters on the basis of their present-day MFs, combined with our understanding of their dynamical and photometric evolution. Methods. We derive the clusters' present-day MFs below 1.0 Msun using deep observations with the Space Telescope Imaging Spectrograph and updated stellar population synthesis models. Results. Since the relaxation timescales of low-mass stars are very long, dynamical evolution will not have affected the MFs below 1.0 Msun significantly, so that - within the uncertainties - the derived MFs are consistent with the solar-neighbourhood IMF, at least for the younger clusters. Conclusions. The IMF in the low-density, low-metallicity environment of the LMC disk is not significantly different from that in the solar neighbourhood.