The fraction of binary systems in the core of five Galactic open clusters

Sollima, A.; Carballo-Bello, J. A.; Beccari, G.; Ferraro, F. R.; Pecci, F. Fusi; Lanzoni, B.
Bibliographical reference

Monthly Notices of the Royal Astronomical Society, Volume 401, Issue 1, pp. 577-585.

Advertised on:
1
2010
Number of authors
6
IAC number of authors
2
Citations
70
Refereed citations
64
Description
We used deep wide-field photometric observations to derive the fraction of binary systems in a sample of five high-latitude Galactic open clusters. By analysing the colour distribution of main-sequence stars, we derived the minimum fraction of binary systems required to reproduce the observed colour-magnitude diagram morphologies. We found that all the analysed clusters contain a minimum binary fraction larger than 11 per cent within the core radius. The estimated global fractions of binary systems range from 35 to 70 per cent depending on the cluster. The comparison with homogeneous estimates performed in globular clusters indicates that open clusters hold a significantly higher fraction of binary systems, as predicted by theoretical models and N-body simulations. A dependence of the relative fraction of binary systems on the cluster mass has been detected, suggesting that the binary disruption within the cluster core is the dominant process that drives the fraction of binaries in stellar systems. Based on the data obtained from the European Southern Observatory Science Archive Facility and Isaac Newton Group Archive. E-mail: asollima [at] iac.es (asollima[at]iac[dot]es)
Related projects
Group members
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
Ignacio
Martín Navarro