Astronomy and Astrophysics, volume 474, 77-104 (2007/10-4)
The primordial binary population. II. Recovering the binary population for intermediate mass stars in Scorpius OB2.
KOUWENHOVEN M.B.N., BROWN A.G.A., PORTEGIES ZWART S.F. and KAPER L.
Abstract (from CDS):
We characterize the binary population in the young and nearby OB association Scorpius OB2
) using available observations of visual, spectroscopic, and astrometric binaries with intermediate-mass primaries. We take into account observational biases by comparing the observations with simulated observations of model associations. The available data indicate a large binary fraction (>70% with 3σ confidence), with a large probability that all intermediate mass stars in Sco OB2
are part of a binary system. The binary systems have a mass ratio distribution of the form fq
q_^, with γq
≃-0.4. Sco OB2
has a semi-major axis distribution of the form fa
a_^ with γa
≃-1.0 (Oepik's law), in the range 5R☉
. The log-normal period distribution of Duquennoy & Mayor (1991A&A...248..485D
) results in too few spectroscopic binaries, even if the model binary fraction is 100%. Sco OB2
is a young association with a low stellar density; its current population is expected to be very similar to the primordial population. The fact that practically all stars in Sco OB2
are part of a binary (or multiple) system demonstrates that multiplicity is a fundamental factor in the star formation process, at least for intermediate mass stars.
Galaxy: open clusters and associations: individual: Scorpius OB2 - stars: binaries: visual - stars: binaries: general - stars: formation
View the reference in ADS
To bookmark this query, right click on this link: simbad:2007A&A...474...77K and select 'bookmark this link' or equivalent in the popup menu