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Title: MONTE CARLO SIMULATIONS OF GLOBULAR CLUSTER EVOLUTION. V. BINARY STELLAR EVOLUTION

Journal Article · · Astrophysical Journal
; ;  [1];  [2]
  1. Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States)
  2. Kavli Institute for Theoretical Physics, UCSB, Santa Barbara, CA 93106 (United States)

We study the dynamical evolution of globular clusters containing primordial binaries, including full single and binary stellar evolution using our Monte Carlo cluster evolution code updated with an adaptation of the single and binary stellar evolution codes SSE and BSE from Hurley et al. We describe the modifications that we have made to the code. We present several test calculations and comparisons with existing studies to illustrate the validity of the code. We show that our code finds very good agreement with direct N-body simulations including primordial binaries and stellar evolution. We find significant differences in the evolution of the global properties of the simulated clusters using stellar evolution compared with simulations without any stellar evolution. In particular, we find that the mass loss from the stellar evolution acts as a significant energy production channel simply by reducing the total gravitational binding energy and can significantly prolong the initial core contraction phase before reaching the binary-burning quasi-steady state of the cluster evolution. We simulate a large grid of models varying the initial cluster mass, binary fraction, and concentration parameter, and we compare properties of the simulated clusters with those of the observed Galactic globular clusters (GGCs). We find that simply including stellar evolution in our simulations and assuming the typical initial cluster half-mass radius is approximately a few pc independent of mass, our simulated cluster properties agree well with the observed GGC properties such as the core radius and the ratio of the core radius to the half-mass radius. We explore in some detail qualitatively different clusters in different phases of their evolution and construct synthetic Hertzsprung-Russell diagrams for these clusters.

OSTI ID:
21454972
Journal Information:
Astrophysical Journal, Vol. 719, Issue 1; Other Information: DOI: 10.1088/0004-637X/719/1/915; ISSN 0004-637X
Country of Publication:
United States
Language:
English