Age and metallicity of star clusters in the Small Magellanic Cloud from integrated spectroscopy

TL;DR

This study derives ages and metallicities of 14 Small Magellanic Cloud star clusters using integrated spectroscopy and full-spectrum fitting, revealing new intermediate/old age clusters and confirming known ages, aiding understanding of galaxy evolution.

Contribution

It introduces a full-spectrum fitting approach applied to integrated spectra of SMC clusters, identifying new intermediate/old age clusters and confirming ages of known ones.

Findings

Identification of new intermediate/old age clusters HW1, NGC 152, Lindsay 3, Lindsay 11, Lindsay 113

Confirmation of old ages for NGC 361, NGC 419, Kron 3, and NGC 121

Derived ages and metallicities for 14 clusters using three stellar population models

Abstract

Context: Analysis of ages and metallicities of star clusters in the Magellanic Clouds provide information for studies on the chemical evolution of the Clouds and other dwarf irregular galaxies. Aims: The aim is to derive ages and metallicities from integrated spectra of 14 star clusters in the Small Magellanic Cloud, including a few intermediate/old age star clusters. Methods: Making use of a full-spectrum fitting technique, we compared the integrated spectra of the sample clusters to three different sets of single stellar population models, using two fitting codes available in the literature. Results: We derive the ages and metallicities of 9 intermediate/old age clusters, some of them previously unstudied, and 5 young clusters. Conclusions: We point out the interest of the newly identified as intermediate/old age clusters HW1, NGC 152, Lindsay 3, Lindsay 11, and Lindsay 113. We also confirm the old ages of NGC 361, NGC 419, Kron 3, and of the very well-known oldest SMC cluster, NGC 121.