How do binary clusters form?

Arnold, Becky; P. Goodwin, Simon; Griffiths, D. W.; Parker, Richard. J.

Abstract

Approximately 10 per cent of star clusters are found in pairs, known as binary clusters. We propose a mechanism for binary cluster formation; we use N-body simulations to show that velocity substructure in a single (even fairly smooth) region can cause binary clusters to form. This process is highly stochastic and it is not obvious from a region's initial conditions whether a binary will form and, if it does, which stars will end up in which cluster. We find the probability that a region will divide is mainly determined by its virial ratio, and a virial ratio above 'equilibrium' is generally necessary for binary formation. We also find that the mass ratio of the two clusters is strongly influenced by the initial degree of spatial substructure in the region.

Citation

Arnold, B., P. Goodwin, S., Griffiths, D. W., & Parker, R. J. (2017). How do binary clusters form?. Monthly Notices of the Royal Astronomical Society, 471(2), 2498-2507. https://doi.org/10.1093/mnras/stx1719

• Journal Article Type: Article
• Acceptance Date: Jul 7, 2017
• Online Publication Date: Jul 13, 2017
• Publication Date: 2017-10
• Deposit Date: Jun 13, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 471
• Issue: 2
• Pages: 2498-2507
• DOI: https://doi.org/10.1093/mnras/stx1719
• Keywords: Astrophysics of Galaxies; Solar and Stellar Astrophysics