On the star formation efficiencies and evolution of multiple stellar generations in Globular Clusters
arXiv:1905.10183 · doi:10.3847/1538-4357/ab2455
Abstract
By adopting empirical estimates of the Helium enhancement (Delta Y) between consecutive stellar generations for a sample of Galactic globular clusters (GGC), we uniquely constraint the star formation efficiency of each stellar generation in these stellar systems. In our approach, the star formation efficiency is the central factor that links stellar generations as it defines both their stellar mass and the remaining mass available for further star formation, fixing also the amount of matter required to contaminate the next stellar generation. In this way, the star formation efficiency is here shown to be fully defined by the He enhancement between successive stellar generations in a GC. Our approach has also an impact on the evolution of clusters and thus considers the possible loss of stars through evaporation, tidal interactions and stellar evolution. We focus on the present mass ratio between consecutive stellar generations and the present total mass of Galactic globular clusters. Such considerations suffice to determine the relative proportion of stars of consecutive generations that remain today in globular clusters. The latter is also shown to directly depend on the values of Delta Y and thus the He enhancement between consecutive stellar generations in GGC places major constraints on models of star formation and evolution of GC.
19 pages, 4 figures, accepted for publication in The Astrophysical Journal
References in corpus (11)
- Binary interaction dominates the evolution of massive stars
- Binary Population and Spectral Synthesis Version 2.1: construction, observational verification and new results
- Formation and Dynamical Evolution of Multiple Stellar Generations in Globular Clusters
- The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. IX. The Atlas of Multiple Stellar Populations
- On the self-enrichment scenario of galactic globular clusters: Constraints on the IMF
- The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. II. The seven stellar populations of NGC7089 (M2)
- A General Abundance Problem for All Self-Enrichment Scenarios for the Origin of Multiple Populations in Globular Clusters
- The primordial and evolutionary abundance variations in globular-cluster stars: a problem with two unknowns
- Gas expulsion vs gas retention: what process dominates in young massive clusters?
- Evidence of AGB pollution in Galactic globular clusters from the Mg-Al anticorrelations observed by the APOGEE survey
- On the determination of the He abundance distribution in globular clusters from the width of the main sequence