An Analysis of the Population of Extended Main Sequence Turn-off Clusters in the Large Magellanic Cloud

Abstract

We combine a number of recent studies of the extended main sequence turn-off (eMSTO) phenomenon in intermediate age stellar ($1-2$ Gyr) clusters in the Large Magellanic Cloud (LMC) in order to investigate its origin. By employing the largest sample of eMSTO LMC clusters so far used, we show that cluster core radii, masses, and dynamical state are not related to the genesis of eMSTOs. Indeed, clusters in our sample have core radii, masses and age-relaxation time ratios in the range $\approx$ 2--6 pc, 3.35- 5.50 (log($M_{cls}$/$M_{\odot }$) and 0.2-8.0, respectively. These results imply that the eMSTO phenomenon is not caused by actual age spreads within the clusters. Furthermore, we confirm from a larger cluster sample recent results including young eMSTO LMC clusters, that the FWHM at the MSTOs correlates most strongly with cluster age, suggesting that a stellar evolutionary effect is the underlying cause.

11 pages, 8 figures, accepted for publication in MNRAS

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Cited by in corpus (8)

• Extended Main Sequence Turnoffs in Intermediate-Age Star Clusters: Stellar Rotation diminishes, but does not eliminate, Age Spreads
• Highly dynamically evolved intermediate-age open clusters
• Observational hints of a real age spread in the young LMC star cluster NGC 1971
• The effects of the overshooting of the convective core on main-sequence turnoffs of young- and intermediate-age star clusters
• NGC1818 unveils the origin of the extended main-sequence turn-off in young Magellanic Clouds clusters
• On the Precision of Full-Spectrum Fitting of Simple Stellar Populations. IV. A Systematic Comparison with Results from Colour-Magnitude Diagrams
• The VISCACHA Survey: XIII. The extended main-sequence turn-off in intermediate-age low-mass clusters
• Searching for chemical abundance variations in young star clusters in the Magellanic Clouds: NGC 411, NGC 1718 and NGC 2213