@inbook{0e61e428c51d4feaa14319c55e0cecc7,
title = "The origin of very wide binary systems",
abstract = "The majority of stars in the Galactic field and halo are part of binary or multiple systems. A significant fraction of these systems have orbital separations in excess of thousands of astronomical units, and systems wider than a parsec have been identified in the Galactic halo. These binary systems cannot have formed through the 'normal' star-formation process, nor by capture processes in the Galactic field. We propose that these wide systems were formed during the dissolution phase of young star clusters. We test this hypothesis using N-body simulations of evolving star clusters and find wide binary fractions of 1-30%, depending on initial conditions. Moreover, given that most stars form as part of a binary system, our theory predicts that a large fraction of the known wide 'binaries' are, in fact, multiple systems.",
keywords = "Binaries: general, Methods: N-body simulations, Stars: formation, Stellar dynamics",
author = "Kouwenhoven, {M. B.N.} and Goodwin, {S. P.} and Parker, {Richard J.} and Davies, {M. B.} and D. Malmberg and P. Kroupa",
note = "Funding Information: MBNK was supported by the Peter and Patricia Gruber Foundation through a PPGF fellowship, the Kavli Foundation, the Peking University One Hundred Talent Fund (985) and by STFC (grant PP/D002036/1). RJP acknowledges support from STFC.",
year = "2009",
doi = "10.1017/S1743921309991633",
language = "English",
isbn = "9780521764995",
series = "Proceedings of the International Astronomical Union",
publisher = "Cambridge University Press",
number = "S266",
pages = "438--441",
booktitle = "Star clusters",
edition = "S266",
}