Abstract
We study the evolution of binary stars in globular clusters using a new Monte Carlo approach combining a population synthesis code (STARTRACK) and a simple treatment of dynamical interactions in the dense cluster core using a new tool for computing three- and four-body interactions (FEWBODY). We find that the combination of stellar evolution and dynamical interactions (binary-single and binary-binary) leads to a rapid depletion of the binary population in the cluster core. The maximum binary fraction today in the core of a typical dense cluster such as 47 Tuc, assuming an initial binary fraction of 100 per cent, is only ∼5-10 per cent. We show that this is in good agreement with recent Hubble Space Telescope observations of close binaries in the core of 47 Tuc, provided that a realistic distribution of binary periods is used to interpret the results. Our findings also have important consequences for the dynamical modelling of globular clusters, suggesting that 'realistic models' should incorporate much larger initial binary fractions than has usually been the case in the past.
Original language | English (US) |
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Pages (from-to) | 572-584 |
Number of pages | 13 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 358 |
Issue number | 2 |
DOIs | |
State | Published - Apr 1 2005 |
Keywords
- Binaries: close
- Binaries: general
- Globular clusters: general
- Globular clusters: individual: NGC 104 (47 Tucanae)
- Methods: N-body simulations
- Stellar dynamics
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science