Self-consistent physical parameters for MC clusters from CMD modelling: application to SMC clusters observed with the SOAR telescope

TL;DR

This paper introduces a method to derive consistent physical parameters of star clusters in the Small Magellanic Cloud using CMD modeling, aiding in understanding their evolution and calibrating stellar population models.

Contribution

The authors develop a new approach for determining age, metallicity, distance, and reddening of SMC clusters from CMDs, applied to clusters observed with the SOAR telescope.

Findings

Lindsay 2 is an intermediate-age cluster (~2.6 Gyr) with [Fe/H] ~ -1.3.

The method confirms previous spectral and color analyses.

Lindsay 2 indicates recent star formation reactivation in the MCs.

Abstract

The Magellanic Clouds (MCs) present a rich system of stellar clusters that can be used to probe the dynamical and chemical evolution of these neighboring and interacting irregular galaxies. In particular, these stellar clusters (SCs) present combinations of age and metallicity that are not found for this class of objects in the Milky Way, being therefore very useful templates to test and to calibrate integrated light simple stellar population (SSP) models applied to unresolved distance galaxies. On its turn, the age and metallicity for a cluster can be determined spatially resolving its stars, by means of analysis of its colour-magnitude diagrams (CMDs). In this work we present our method to determine self-consistent physical parameters (age, metallicity, distance modulus and reddening) for a stellar cluster, from CMDs modelling of relatively unstudied SCs in the Small Magellanic Cloud (SMC) imaged in the BVI filters with the 4.1 m SOAR telescope. Our preliminary results confirm our expectations that come from a previous integrated spectra and colour analysis: at least one of them (Lindsay 2) is an intermediate-age stellar cluster with ~ 2.6 Gyr and [Fe/H] ~ -1.3, being therefore a new interesting witness regarding the reactivation of the star formation in the MCs in the last 4 Gyr.