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

A.E. PIATTI, N. BASTIAN

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 463 p. 1632 - 1641

0035-8711

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 thegenesis of eMSTOs. Indeed, clusters in our sample have core radii, masses and age-relaxationtime 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 resultsincluding 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.