The mass ratio distribution of B-type visual binaries in the Sco OB2 association

By N. Shatsky, A. Tokovinin. 2001

299 citations recorded by the source corpus.

A sample of 115 B-type stars in the Sco OB2 association is examined for existence of visual companions in the J and K s bands, using the ADONIS near-infrared adaptive optics system and coronograph. Practically all the components in the separation range $0\farcs3$–$6\farcs4$ (45–900 AU) and magnitudes down to $K\!=\!16$ were detected. The K and $J\!-\!K$ photometry of the primaries and differential photometry and astrometry of the 96 secondaries are presented. Ten secondaries are new physical components, as inferred from the photometric and statistical criteria, while the rest of the newly detected objects are faint background stars. After a small correction for detection incompleteness and a conversion of the fluxes into masses, an unbiased distribution of the components mass ratio q was derived. The power law $f(q)\propto q^{-0.5}$ fits the observations well, whereas a q -1.8 distribution, which corresponds to a random pairing of stars, is rejected. The companion star fraction is $0.20\pm0.04$ per decade of separation which is comparable to the highest measured binary fraction among low-mass PMS stars and ~1.6 times higher than the binary fraction of low-mass dwarfs in the solar neighborhood and in open clusters in the same separation range.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/a712d46892e1647cc0de79681b9724c0f0f7e4a3

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Citations in the corpus

Tertiary Companions to Close Spectroscopic Binaries (2006, methodology): “A similar model was used by Shatsky & Tokovinin (2002).”
The Close Binary Fraction of Solar-type Stars Is Strongly Anticorrelated with Metallicity (2018, methodology): “The frequency then declines to flog P≈0.10–0.20 across log P(days)=5–7 according to adaptive optics, speckle imaging, visual observations, and common proper motion astrometry of wide companions to early-B stars (Abt et al. 1990; Duchêne et al. 2001; Shatsky & Tokovinin 2002; Peter et al. 2012).”
Stellar, brown dwarf and multiple star properties from a radiation hydrodynamical simulation of star cluster formation (2011, background): “…fraction of stars or brown dwarfs that are in multiple systems increases with stellar mass (massive stars: Mason et al. 1998; Preibisch et al. 1999; Shatsky & Tokovinin 2002; Kobulnicky & Fryer 2007; Kouwenhoven et al. 2007b; Mason et al. 2009; intermediate-mass stars: Patience et al. 2002;…”
THE ASTRALUX LARGE M-DWARF MULTIPLICITY SURVEY (2012, background): “By contrast, for more massive stars in the AB-type range, upward of 80% appear to be in multiples (Shatsky & Tokovinin 2002; Kouwenhoven et al. 2007; Peter et al. 2012).”
Long-baseline interferometric multiplicity survey of the Sco-Cen OB association (2013, methodology): “In the Bayesian analysis of the multiplicity distribution which follows, we combine these detection limits with those of Shatsky & Tokovinin (2002).”
Stellar Multiplicity (2013, methodology): “…is the best studied region to date, both for SBs (e.g., Brown & Verschueren 1997) and visual companions (Kouwenhoven, Brown & Kaper 2007a, Shatsky & Tokovinin 2002), which allowed Kouwenhoven et al. (2007b) to perform a systematic analysis to derive the global multiplicity properties of…”
STELLAR POPULATIONS IN THE CENTRAL 0.5 pc OF THE GALAXY. II. THE INITIAL MASS FUNCTION (2013, background): “…a cluster (e.g. Ghez et al. 1993; Petr et al. 1998; Mason et al. 1998; Duchêne et al. 1999; Köhler et al. 2000; Reipurth 2000; Patience et al. 2002; Shatsky & Tokovinin 2002; Köhler et al. 2006; Duchêne et al. 2007; Köhler et al. 2008; Mason et al. 2009; Raghavan et al. 2010; Kraus &…”
The primordial binary population. I. A near-infrared adaptive optics search for close visual companions to A star members of Scorpius OB2 (2004, unknown): “This is similar to the mass ratio distribution observed by Shatsky & Tokovinin (2002) for systems with B type primaries.”
Stellar Multiplicity and the Initial Mass Function: Most Stars Are Single (2006, unknown): “In this context it would be interesting to know if the trend of increasing stellar multiplicity with stellar mass continues to the more massive A, B and O stars, as has been suggested in some studies (e.g., Preibisch, Weigelt, & Zinnecker 2001, Shatsky & Tokovinin 2002).”
The Initial Mass Function of the Massive Star-forming Region NGC 3603 from Near-Infrared Adaptive Optics Observations (2007, methodology): “For some clusters the mass ratio distribution can be fitted by an inverse power law f(q) ∝ q−Γ, for example, with Γ = 0.33 − 0.5 in Sco OB2 (Shatsky & Tokovinin 2002; Kouwenhoven et al. 2005) and Γ = 1.3 in the Hyades cluster (Patience et al. 1998).”
The formation of very wide binaries during the star cluster dissolution phase (2010, background): “…fraction of stars in the Galactic field are in binary and multiple systems (e.g, Duquennoy & Mayor 1991; Fischer & Marcy 1992; Mason et al. 1998; Shatsky & Tokovinin 2002; Goodwin & Kroupa 2005; Kobulnicky & Fryer 2007; Kouwenhoven et al. 2005, 2007; Lada 2006; Zinnecker & Yorke 2007; Goodwin…”
THE HIGH ANGULAR RESOLUTION MULTIPLICITY OF MASSIVE STARS (2008, background): “The total mass of the system is approximately 27 M for a distance of 140 pc (Shatsky & Tokovinin 2002).”
Binaries and the L Dwarf/T Dwarf Transition (2006, background): “While there is evidence that the binary fraction of stars decreases across several stellar classes (Duquennoy& Mayor 1991; Fischer &Marcy 1992; Shatsky & Tokovinin 2002; Bouy et al. 2004), no trend has been established within the substellar regime.”
Mind Your Ps and Qs: The Interrelation between Period (P) and Mass-ratio (Q) Distributions of Binary Stars (2016, methodology): “Adaptive optics are sensitive to q = 0.1 companions for angular separations ρ > 0.5′′ while incompleteness and observational biases become important beyond ρ > 4′′ (Shatsky & Tokovinin 2002, see their Fig.”
The Volume-limited A-Star (VAST) survey – I. Companions and the unexpected X-ray detection of B6–A7 stars (2011, background): “These observations typically identified the B-type star as the source of X-ray emission, although subsequent high-resolution AO imaging has revealed additional components to several of these systems (e.g. Shatsky & Tokovinin 2002).”
Adaptive Optics for Astronomy (2012, background): “The outer part shows the dust disk observed in the K-band with ADONIS; the central part is an L-band image from NaCO on the VLT which shows a companion 0.4′′ (8AU) to the north-west of the star (image credit: ESO/A.-M. Lagrange et al).”
THE PALOMAR/KECK ADAPTIVE OPTICS SURVEY OF YOUNG SOLAR ANALOGS: EVIDENCE FOR A UNIVERSAL COMPANION MASS FUNCTION (2008, background): “Our determination that β = −0.39 ± 0.36 for companions to solar mass stars indicates that the shape of the CMF found by Shatsky & Tokovinin (2002) and Kouwenhoven et al. (2005) is not specific to intermediate mass stars.”