Dynamical mixing of two stellar populations in globular clusters

Abstract

Stars in globular clusters (GCs) exhibit a peculiar chemical pattern with strong abundance variations in light elements along with a constant abundance in heavy elements. These abundance anomalies can be explained by a primordial pollution due to a first generation of fast rotating massive stars which released slow winds into the ISM from which a second generation of chemically anomalous stars can be formed. In particular the observed ratio of anomalous and standard stars in clusters can be used to constrain the dynamical evolution of GCs as around 95% of the standard stars need to be lost by the clusters. We show that both residual gas expulsion during the cluster formation and long term evolution are needed to achieve this ratio.Comment: 4 pages, 4 figures, accepted for publicatio in A

The Hubble Space Telescope UV Legacy Survey of Galactic globular clusters – XIV. Multiple stellar populations within M 15 and their radial distribution★

“…D' Ercole et al 2008Ercole et al , 2010. The fact that some clusters would still retain information on the initial distribution of 1G and 2G stars makes the study of their radial distribution a powerful tool to shed light on the MP phenomenon ( Decressin et al 2008;Vesperini et al 2013).…”