Dunstall, PR;
Dufton, PL;
Sana, H;
Evans, CJ;
Howarth, ID;
Simon-Diaz, S;
de Mink, SE;
... Taylor, WD; + view all
(2015)
The VLT-FLAMES Tarantula Survey XXII. Multiplicity properties of the B-type stars.
Astronomy & Astrophysics
, 580
(A93)
10.1051/0004-6361/201526192.
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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−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.
| Type: | Article |
|---|---|
| Title: | The VLT-FLAMES Tarantula Survey XXII. Multiplicity properties of the B-type stars |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1051/0004-6361/201526192 |
| Publisher version: | http://doi.org/10.1051/0004-6361/201526192 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | stars: early-type – binaries: spectroscopic – Open clusters and associations: individual: 30 Dorad |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1499865 |
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