The VLT-FLAMES Tarantula Survey XXII. Multiplicity properties of the B-type stars

P. R. Dunstall; P. L. Dufton; H. Sana; C. J. Evans; I. D. Howarth; S. Simón-Díaz; S. E. De Mink; N. Langer; J. Maíz Apellániz; W. D. Taylor

doi:10.1051/0004-6361/201526192

The VLT-FLAMES Tarantula Survey XXII. Multiplicity properties of the B-type stars

P. R. Dunstall
, P. L. Dufton
, H. Sana
, C. J. Evans
, I. D. Howarth
, S. Simón-Díaz
, S. E. De Mink
, N. Langer
, J. Maíz Apellániz
, W. D. Taylor

Research output: Contribution to journal › Article › peer-review

147 Citations (Scopus)

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Abstract

We investigate the multiplicity properties of 408 B-type stars observed in the 30 Doradus region of the Large Magellanic Cloud with multi-epoch spectroscopy from the VLT-FLAMES Tarantula Survey (VFTS). We use a cross-correlation method to estimate relative radial velocities from the helium and metal absorption lines for each of our targets. Objects with significant radial-velocity variations (and with an amplitude larger than 16 km s<sup>-1</sup>) are classified as spectroscopic binaries. We find an observed spectroscopic binary fraction (defined by periods of <10<sup>3.5</sup> d and mass ratios >0.1) for the B-type stars, f<inf>B</inf>(obs) = 0.25 ± 0.02, which appears constant across the field of view, except for the two older clusters (Hodge 301 and SL 639). These two clusters have significantly lower binary fractions of 0.08 ± 0.08 and 0.10 ± 0.09, respectively. Using synthetic populations and a model of our observed epochs and their potential biases, we constrain the intrinsic multiplicity properties of the dwarf and giant (i.e. relatively unevolved) B-type stars in 30 Dor. We obtain a present-day binary fraction f<inf>B</inf>(true) = 0.58 ± 0.11, with a flat period distribution. Within the uncertainties, the multiplicity properties of the B-type stars agree with those for the O stars in 30 Dor from the VFTS.

Original language	English
Article number	A93
Pages (from-to)	1-10
Number of pages	10
Journal	Astronomy and Astrophysics
Volume	580
DOIs	https://doi.org/10.1051/0004-6361/201526192
Publication status	Published - 01 Aug 2015

Keywords

Binaries: spectroscopic
Open clusters and associations: individual: 30 Doradus
Stars: early-type

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1051/0004-6361/201526192

The VLT-FLAMES Tarantula Survey XXII. Multiplicity properties of the B-type stars
Copyright ESO 2015.
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@article{e035e47b662d45ebbbfbf5a6af66871f,

title = "The VLT-FLAMES Tarantula Survey XXII. Multiplicity properties of the B-type stars",

abstract = "We investigate the multiplicity properties of 408 B-type stars observed in the 30 Doradus region of the Large Magellanic Cloud with multi-epoch spectroscopy from the VLT-FLAMES Tarantula Survey (VFTS). We use a cross-correlation method to estimate relative radial velocities from the helium and metal absorption lines for each of our targets. Objects with significant radial-velocity variations (and with an amplitude larger than 16 km s-1) are classified as spectroscopic binaries. We find an observed spectroscopic binary fraction (defined by periods of <103.5 d and mass ratios >0.1) for the B-type stars, fB(obs) = 0.25 ± 0.02, which appears constant across the field of view, except for the two older clusters (Hodge 301 and SL 639). These two clusters have significantly lower binary fractions of 0.08 ± 0.08 and 0.10 ± 0.09, respectively. Using synthetic populations and a model of our observed epochs and their potential biases, we constrain the intrinsic multiplicity properties of the dwarf and giant (i.e. relatively unevolved) B-type stars in 30 Dor. We obtain a present-day binary fraction fB(true) = 0.58 ± 0.11, with a flat period distribution. Within the uncertainties, the multiplicity properties of the B-type stars agree with those for the O stars in 30 Dor from the VFTS.",

keywords = "Binaries: spectroscopic, Open clusters and associations: individual: 30 Doradus, Stars: early-type",

author = "Dunstall, \{P. R.\} and Dufton, \{P. L.\} and H. Sana and Evans, \{C. J.\} and Howarth, \{I. D.\} and S. Sim{\'o}n-D{\'i}az and \{De Mink\}, \{S. E.\} and N. Langer and \{Ma{\'i}z Apell{\'a}niz\}, J. and Taylor, \{W. D.\}",

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doi = "10.1051/0004-6361/201526192",

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T1 - The VLT-FLAMES Tarantula Survey XXII. Multiplicity properties of the B-type stars

AU - Dunstall, P. R.

AU - Dufton, P. L.

AU - Sana, H.

AU - Evans, C. J.

AU - Howarth, I. D.

AU - Simón-Díaz, S.

AU - De Mink, S. E.

AU - Langer, N.

AU - Maíz Apellániz, J.

AU - Taylor, W. D.

PY - 2015/8/1

Y1 - 2015/8/1

N2 - We investigate the multiplicity properties of 408 B-type stars observed in the 30 Doradus region of the Large Magellanic Cloud with multi-epoch spectroscopy from the VLT-FLAMES Tarantula Survey (VFTS). We use a cross-correlation method to estimate relative radial velocities from the helium and metal absorption lines for each of our targets. Objects with significant radial-velocity variations (and with an amplitude larger than 16 km s-1) are classified as spectroscopic binaries. We find an observed spectroscopic binary fraction (defined by periods of <103.5 d and mass ratios >0.1) for the B-type stars, fB(obs) = 0.25 ± 0.02, which appears constant across the field of view, except for the two older clusters (Hodge 301 and SL 639). These two clusters have significantly lower binary fractions of 0.08 ± 0.08 and 0.10 ± 0.09, respectively. Using synthetic populations and a model of our observed epochs and their potential biases, we constrain the intrinsic multiplicity properties of the dwarf and giant (i.e. relatively unevolved) B-type stars in 30 Dor. We obtain a present-day binary fraction fB(true) = 0.58 ± 0.11, with a flat period distribution. Within the uncertainties, the multiplicity properties of the B-type stars agree with those for the O stars in 30 Dor from the VFTS.

AB - We investigate the multiplicity properties of 408 B-type stars observed in the 30 Doradus region of the Large Magellanic Cloud with multi-epoch spectroscopy from the VLT-FLAMES Tarantula Survey (VFTS). We use a cross-correlation method to estimate relative radial velocities from the helium and metal absorption lines for each of our targets. Objects with significant radial-velocity variations (and with an amplitude larger than 16 km s-1) are classified as spectroscopic binaries. We find an observed spectroscopic binary fraction (defined by periods of <103.5 d and mass ratios >0.1) for the B-type stars, fB(obs) = 0.25 ± 0.02, which appears constant across the field of view, except for the two older clusters (Hodge 301 and SL 639). These two clusters have significantly lower binary fractions of 0.08 ± 0.08 and 0.10 ± 0.09, respectively. Using synthetic populations and a model of our observed epochs and their potential biases, we constrain the intrinsic multiplicity properties of the dwarf and giant (i.e. relatively unevolved) B-type stars in 30 Dor. We obtain a present-day binary fraction fB(true) = 0.58 ± 0.11, with a flat period distribution. Within the uncertainties, the multiplicity properties of the B-type stars agree with those for the O stars in 30 Dor from the VFTS.

KW - Binaries: spectroscopic

KW - Open clusters and associations: individual: 30 Doradus

KW - Stars: early-type

U2 - 10.1051/0004-6361/201526192

DO - 10.1051/0004-6361/201526192

M3 - Article

AN - SCOPUS:84938926593

SN - 0004-6361

VL - 580

SP - 1

EP - 10

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

M1 - A93

ER -

The VLT-FLAMES Tarantula Survey XXII. Multiplicity properties of the B-type stars

Abstract

Keywords

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