J/MNRAS/437/1216 VAST Survey. A-type stars multiplicity (De Rosa+, 2014)
The VAST Survey. III. The multiplicity of A-type stars within 75pc.
De Rosa R.J., Patience J., Wilson P.A., Schneider A., Wiktorowicz S.J.,
Vigan A., Marois C., Song I., Macintosh B., Graham J.R., Doyon R.,
Bessell M.S., Thomas S., Lai O.
<Mon. Not. R. Astron. Soc., 437, 1216-1240 (2014)>
=2014MNRAS.437.1216D 2014MNRAS.437.1216D
ADC_Keywords: Stars, nearby ; Stars, double and multiple ; Stars, A-type
Keywords: techniques: high angular resolution - binaries: close -
binaries: general - binaries: visual - stars: early-type
Abstract:
With a combination of adaptive optics imaging and a multi-epoch common
proper motion search, we have conducted a large volume-limited
(D≤75pc) multiplicity survey of A-type stars, sensitive to companions
beyond 30AU. 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
45000AU. 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 distribution, but with a peak shifted
to a significantly wider value of 387+132-98AU. Integrating the
fit to the distribution over the 30 to 10000AU observed range, the
companion star fraction for A-type stars is estimated as 33.8±2.6%.
The mass ratio distribution of closer (<125AU) 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%. 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, quadruple and quintuple A-type star systems of
56.4-4.0+3.8, 32.1-3.5+3.9, 9.0-1.8+2.8, 1.9-0.6+1.8
and 0.6-0.2+1.4 percent, respectively.
Description:
To measure the frequency of stellar binary companions, and the
distribution of their separations and mass ratios, we have obtained
observations of a sample of 435 nearby A-type stars. The sample is
composed of two overlapping sets of A-type stars within 75pc: a 363
star sample observed with AO instrumentation and a 228 star sample
investigated with astrometry obtained from all-sky photographic
surveys, with an overlap of 156 stars.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 112 435 The VAST sample
table2.dat 79 435 Alternative catalogue identifiers
table6.dat 70 113 Binary companions identified within the AO
observations
table7.dat 82 24 Binary companions identified within the
astrometric search
table9.dat 110 98 Companions listed within the literature used in
the calculation of the lower limit of the
multiplicity fraction
--------------------------------------------------------------------------------
See also:
J/MNRAS/422/2765 : A-star multiples orbital motion monitoring (De Rosa+, 2012)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- HIP HIP number
8- 20 A13 --- SpType MK spectral type
22- 25 F4.1 pc Dist Distance
27- 29 F3.1 pc e_Dist rms uncertainty on Dist
31- 34 F4.2 mag BTmag Tycho BT magnitude
36- 39 F4.2 mag e_BTmag rms uncertainty on BTmag
41- 44 F4.2 mag VTmag Tycho VT magnitude
46- 49 F4.2 mag e_VTmag rms uncertainty on VTmag
51- 54 F4.2 mag Jmag ?=- 2MASS J magnitude
56- 59 F4.2 mag e_Jmag ? rms uncertainty on Jmag
61- 64 F4.2 mag Hmag ?=- 2MASS H magnitude
66- 69 F4.2 mag e_Hmag ? rms uncertainty on Hmag
71- 74 F4.2 mag Ksmag 2MASS Ks magnitude
76- 79 F4.2 mag e_Ksmag rms uncertainty on Ksmag
81- 84 I4 Myr Age Star estimated age
86- 87 I2 --- r_Age Reference for Age estimate (1)
89- 92 F4.2 Msun Mass Star mass
94- 97 F4.2 [AU] bSCA ?=- Lower value of separation coverage from
Adapative Optices (2)
99-102 F4.2 [AU] BSCA ?=- Upper value of separation coverage from
Adapative Optices (2)
104-107 F4.2 [AU] bSCC ?=- Lower value of separation coverage from
CPM search (2)
109-112 F4.2 [AU] BSCC ?=- Upper value of separation coverage from
CPM search (2)
--------------------------------------------------------------------------------
Note (1): References as follows:
1 = this work (CMD)
2 = Zuckerman et al. (2011ApJ...732...61Z 2011ApJ...732...61Z)
3 = Tetzlaff et al. (2011MNRAS.410..190T 2011MNRAS.410..190T, Cat. J/MNRAS/410/190)
4 = Rhee et al. (2007ApJ...660.1556R 2007ApJ...660.1556R, Cat. J/ApJ/660/1556)
5 = Su et al. (2006ApJ...653..675S 2006ApJ...653..675S, Cat, J/ApJ/653/675)
6 = Rieke et al. (2005ApJ...620.1010R 2005ApJ...620.1010R, Cat. J/ApJ/620/1010)
7 = Perryman et al. (1998A&A...331...81P 1998A&A...331...81P, Cat. J/A+A/331/81)
8 = Barrado y Navascues (1998A&A...339..831B 1998A&A...339..831B)
9 = Song et al. (2001ApJ...546..352S 2001ApJ...546..352S)
10 = Westin (1985A&AS...60...99W 1985A&AS...60...99W)
11 = Gerbaldi et al. (1999A&AS..137..273G 1999A&AS..137..273G)
12 = King et al. (2003AJ....125.1980K 2003AJ....125.1980K)
13 = Laureijs et al. (2002A&A...387..285L 2002A&A...387..285L)
14 = Stauffer et al. (1995ApJ...454..910S 1995ApJ...454..910S)
15 = Paunzen (1997A&A...326L..29P 1997A&A...326L..29P)
16 = Janson et al. (2011ApJ...736...89J 2011ApJ...736...89J, J/ApJ/736/89)
17 = Torres et al. (2008, Handbook of Star Forming Regions: Vol. II,
The Southern Sky. Bo R., editor. San Francisco: Astron. Soc.
Pac.; 2008. p. 757)
Note (2): the observable separation ranges (a) are in log scale, i.e.
bSCA≤log(a)≤BSCA (Adapative Optices), and
bSCC≤log(a)≤BSCC (Common Proper Motion search)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- HIP HIP number
8- 16 A9 --- Name Name
18- 34 A17 --- Bayer Bayer designation
36- 45 A10 --- Flamsteed Flamsteed designation
46- 49 I4 --- HR ? HR number
51- 56 I6 --- HD HD number
58- 66 A9 --- ADS ADS designation
69- 79 A11 --- WDS WDS designation
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [HIP]
5- 10 I6 --- HIP HIP number
12- 15 A4 --- Comp WDS designation of companion
16- 18 A3 --- n_Comp [a-e, ] Remarks about the companion (1)
20- 24 F5.2 arcsec rho Angular separation ρ
26- 31 F6.1 AU aproj [5/1125] Projected separation
33- 37 F5.1 deg theta [0/360] Position angle θ
39 A1 --- n_Dm [KH] Band (filter) of Δm
41- 44 F4.2 mag Dm Difference in magnitude Δm between the
two components
46- 49 F4.2 Msun M1 Mass of the primary
51- 54 F4.2 Msun M2 Mass of the secondary
56- 59 F4.2 --- q [0/1] Mass ratio (M2/M1)
61- 70 A10 "date" Date Observation date
--------------------------------------------------------------------------------
Note (1): Notes as follows:
a = A newly resolved binary without a designation assigned within the
WDS catalogue
b = HIP 4979 B is resolved into a binary system itself
c = The secondary in this pair is a known binary which is unresolved within
the AO observations
d = The primary in this pair is a known binary which is unresolved within
the AO observations
e = HIP 91926 CD is a wide CPM companion to HIP 91919 AB
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [HIP]
5- 10 I6 --- HIP HIP number
12- 31 A20 --- Comp Companion designation
33- 34 A2 --- Mult WDS designation of multiplicity components
35 A1 --- n_Mult [a] newly resolved binary without a
designation assigned in the WDS catalogue
37- 42 F6.1 arcsec rho Angular separation ρ
44- 50 F7.1 AU aproj [1133/43822] Projected separation
52- 56 F5.2 [AU] logaproj log of Projected separation
58- 62 F5.1 deg theta [0/360] Position angle θ
64- 67 F4.2 mag DK Difference in K magnitude between the
two components
69- 72 F4.2 Msun M1 Mass of the primary
74- 77 F4.2 Msun M2 Mass of the secondary
79- 82 F4.2 --- q Mass ratio (M2/M1)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- HIP HIP number
8- 13 A6 --- Comp Companion designation
15- 19 F5.2 [d] logP ?=- Orbital period (log scale)
21 A1 --- l_rho Limit flag on rho
22- 29 F8.2 arcsec rho ?=- Angular separation ρ
32-110 A79 --- Ref Reference
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
De Rosa et al., Paper I 2011MNRAS.415..854D 2011MNRAS.415..854D
De Rosa et al., Paper II 2012MNRAS.422.2765D 2012MNRAS.422.2765D, Cat. J/MNRAS/422/2765
(End) Patricia Vannier [CDS] 10-Nov-2014