The VAST Survey - III. The multiplicity of A-type stars within 75 pc

By R. J. Rosa, J. Patience, P. Wilson, A. Schneider, S. Wiktorowicz, A. Vigan, C. Marois, Inseok Song, B. Macintosh, J. Graham and 4 more. 2013

313 citations recorded by the source corpus.

With a combination of adaptive optics imaging and a multi-epoch common proper motion search, we have conducted a large volume-limited (D 6 75 pc) multiplicity survey of A- type stars, sensitive to companions beyond 30 au. The sample for the Volume- limited A- STar (VAST) survey consists of 435 A-type stars: 363 stars were observed with adaptive optics, 228 stars were searched for wide common proper motion companions and 156 stars were measured with both techniques. The projected separation coverage of the VAST survey extends from 30 to 45,000 au. A total of 137 stellar companions were resolved, including 64 new detections from the VAST survey, and the companion star fraction, projected separation distribution and mass ratio distribution were measured. The separation distribution forms a log-normal distribution similar to the solar-type binary d istribution, but with a peak shifted to a significantly wider value of 387 +132 98 au. Integrating the fit to the distribution over the 30 to 10,000 au observed range, the companion star fraction for A-type stars is estimated as 33.8 ± 2.6 per cent. The mass ratio distribution of closer (< 125 au) binaries is distinct from that of wider systems, with a flat distribution for close systems and a distribution that tends towards smaller mass ratios for wider binaries. Combining this result with previous spectroscopic surveys of A-type stars gives an estimate of the total companion star fraction of 68.9 ± 7.0 per cent. The most complete assessment of higher order multiples was estimated from the 156-star subset of the VAST sample with both adaptive optics and common proper motion measurements, combined with a thorough literature search for companions, yielding a lower limit on the frequency of single, binary, triple, qua druple and quintuple A-type star

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/f815ad7cffb90575ea6d29a26e603abfd57f852a

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Andrew Vanderburg
2. Timothy Morton
3. J. Johnson
4. S. Toonen
5. J. Becker
6. V. Korol
7. Paul J. Groot
8. E. Rossi

In Atomic and Molecular Physics, and Optics

1. S. Toonen
2. Daniel J. Eisenstein
3. J. Johnson
4. Timothy Morton
5. Andrew Vanderburg
6. G. Nelemans

In Instrumentation

1. Timothy Morton
2. Andrew Vanderburg
3. J. Johnson
4. J. Becker
5. S. O. Kepler
6. C. Kulesa
7. K. Ward-Duong
8. E. Rossi

Citations in the corpus

• New white dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 12 (2015, background): “De Rosa et al. (2014) determine that 69 ± 7% of all A stars in the solar neighborhood are in binaries.”
• Searching for faint companions with VLTI/PIONIER - II. 92 main sequence stars from the Exozodi survey (2014, background): “…result of De Rosa et al. (2014) suggest that about 47% of A-type stars are visual binaries for angular separations ranging from 1 mas to 140′′, although a gap remains between the outer edge of the PIONIER field of view (∼ 100 mas) and the inner edge of the De Rosa et al. (2014) survey (0′′.4).”
• Mind Your Ps and Qs: The Interrelation between Period (P) and Mass-ratio (Q) Distributions of Binary Stars (2016, methodology): “At wide separations ρ > 8′′, there is a >5% probability that VBs with ∆K ≈ 6 mag are optical doubles based on the observed background stellar densities (De Rosa et al. 2014).”
• EXTRACTING RADIAL VELOCITIES OF A- AND B-TYPE STARS FROM ECHELLE SPECTROGRAPH CALIBRATION SPECTRA (2015, background): “De Rosa et al. (2014) identified a further companion at 1643.04 arcseconds.”
• Prospects for detection of detached double white dwarf binaries with Gaia, LSST and LISA (2017, background): “A typical progenitor of a DWD component is an A-type star (De Rosa et al. 2014).”
• The M-dwarfs in Multiples (MinMs) survey – I. Stellar multiplicity among low-mass stars within 15 pc (2015, methodology): “The mass ratio distribution is flat across the q = 0.2 − 1.0 range, similar to that observed for companions to solar-type stars (Raghavan et al. 2010), but different from the rise toward lower mass ratios seen for higher-mass stars (De Rosa et al. 2014).”