SCYON Abstract

Received on February 27 2007

The Dynamical Implications of Multiple Stellar Formation Events in Galactic Globular Clusters

AuthorsJonathan M.B. Downing (1,2) and Alison Sills (2)
Affiliation
(1) Astronomisches Rechen-Institut (ZAH), Germany
(2) Department of Physics and Astronomy, McMaster University, Canada
Accepted byAstrophysical Journal
Contactdownin@ari.uni-heidelberg.de
URLhttp://www.arxiv.org/abs/astro-ph/0702716
Links

Abstract

Various galactic globular clusters display abundance anomalies that affect the morphology of their colour-magnitude diagrams. In this paper we consider the possibility of helium enhancement in the anomalous horizontal branch of NGC 2808. We examine the dynamics of a self-enrichment scenario in which an initial generation of stars with a top-heavy initial mass function enriches the interstellar medium with helium via the low-velocity ejecta of its asymptotic giant branch stars. This enriched medium then produces a second generation of stars which are themselves helium-enriched. We use a direct N-body approach to perform five simulations and conclude that such two-generation clusters are both possible and would not differ significantly from their single-generation counterparts on the basis of dynamics. We find, however, that the stellar populations of such clusters would differ from single-generation clusters with a standard initial mass function and in particular would be enhanced in white dwarf stars. We conclude, at least from the standpoint of dynamics, that two-generation globular clusters are feasible.