The search for multiple populations in Magellanic Clouds clusters - V. Correlation between cluster age and abundance spreads

Abstract

In our HST photometric survey, we have been searching for multiple stellar populations (MPs) in Magellanic Clouds (MCs) massive star clusters which span a significant range of ages ($\sim 1.5-11$ Gyr). In the previous papers of the series, we have shown that the age of the cluster represents one of the key factors in shaping the origin of the chemical anomalies. Here we present the analysis of four additional clusters in the MCs, namely Lindsay 38, Lindsay 113, NGC 2121 and NGC 2155, for which we recently obtained new UV HST observations. These clusters are more massive than $\sim 10^4{M}_{\odot }$ and have ages between $\sim 2.5-6$ Gyr, i.e. located in a previously unexplored region of the cluster age/mass diagram. We found chemical anomalies, in the form of N spreads, in three out of four clusters in the sample, namely in NGC 2121, NGC 2155 and Lindsay 113. By combining data from our survey and HST photometry for 3 additional clusters in the Milky Way (namely 47 Tuc, M15 and NGC 2419), we show that the extent of the MPs in the form of N spread is a strong function of age, with older clusters having larger N spreads with respect to the younger ones. Hence, we confirm that cluster age plays a significant role in the onset of MPs.

Accepted for publication in MNRAS. 12 pages, 9 figures

References in corpus (20)

• A distance to the Large Magellanic Cloud that is precise to one per cent
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. I. Overview of the Project and Detection of Multiple Stellar Populations
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. IX. The Atlas of Multiple Stellar Populations
• Age Determination of Six Intermediate-age SMC Star Clusters with HST/ACS
• Multiple stellar populations in three rich Large Magellanic Cloud star clusters
• Multiple stellar populations in Magellanic Clouds clusters. I. An ordinary feature for intermediate age globulars in the LMC?
• Calcium II Triplet Spectroscopy of LMC Red Giants. I. Abundances and Velocities for a Sample of Populous Clusters
• Looking outside the Galaxy: the discovery of chemical anomalies in 3 old Large Magellanic Cloud clusters
• The chemical composition of red giant stars in four intermediate-age clusters of the Large Magellanic Cloud
• Extended Main Sequence Turnoffs in Intermediate-Age Star Clusters: A Correlation Between Turnoff Width and Early Escape Velocity
• Age as a Major Factor in the Onset of Multiple Populations in Stellar Clusters
• The Search for Multiple Populations in Magellanic Cloud Clusters II: The Detection of Multiple Populations in Three Intermediate-Age SMC Clusters
• Multiple populations in the old and massive Small Magellanic Cloud globular cluster NGC121
• Nitrogen abundances and multiple stellar populations in the globular clusters of the Fornax dSph
• First evidence of fully spatially mixed first and second generations in globular clusters: the case of NGC 6362
• No evidence of chemical anomalies in the bimodal turnoff cluster NGC 1806 in the LMC
• The Search for Multiple Populations in Magellanic Cloud Clusters I: Two Stellar Populations in the Small Magellanic Cloud Globular Cluster NGC 121
• Ca II Triplet Spectroscopy of Small Magellanic Cloud Red Giants. III. Abundances and Velocities for a Sample of 14 Clusters
• Exploring the nature and synchronicity of early cluster formation in the Large Magellanic Cloud IV: Evidence for Multiple Populations in Hodge 11 and NGC 2210
• When does the onset of multiple stellar populations in star clusters occur? Detection of enriched stellar populations in NGC 2121