J/AJ/147/87 From binaries to multiples. II. Statistical data (Tokovinin, 2014)
From binaries to multiples. II. Hierarchical multiplicity of F and G dwarfs.
Tokovinin A.
<Astron. J., 147, 87 (2014)>
=2014AJ....147...87T 2014AJ....147...87T
ADC_Keywords: Stars, double and multiple ; Stars, dwarfs ; Stars, F-type ;
Stars, G-type ; Stars, masses
Keywords: binaries: general - stars: solar-type - stars: statistics
Abstract:
Statistics of hierarchical multiplicity among solar-type dwarfs are
studied using the distance-limited sample of 4847 targets presented in
the accompanying Paper I. Known facts about binaries (multiplicity
fraction 0.46, lognormal period distribution with median period 100yr
and logarithmic dispersion 2.4, and nearly uniform mass-ratio
distribution independent of the period) are confirmed with a high
statistical significance. The fraction of hierarchies with three or
more components is 0.13±0.01, and the fractions of targets with
n=1,2,3,... components are 54:33:8:4:1. Subsystems in the secondary
components are almost as frequent as in the primary components, but in
half of such cases both inner pairs are present. The high frequency of
those 2+2 hierarchies (4%) suggests that both inner pairs were formed
by a common process. The statistics of hierarchies can be reproduced
by simulations, assuming that the field is a mixture coming from
binary-rich and binary-poor environments. Periods of the outer and
inner binaries are selected recursively from the same lognormal
distribution, subject to the stability constraint and accounting for
the correlation between inner subsystems. The simulator can be used to
evaluate the frequency of multiple systems with specified parameters.
However, it does not reproduce the observed excess of inner periods
shorter than 10days, caused by tidal evolution.
Description:
The data on all systems and subsystems in the FG-67 sample (F and G
dwarfs within 67pc of the Sun; see PaperI, Tokovinin 2014, cat.
J/AJ/147/86) are assembled in the structure (Table1), which contains
information on the hierarchical level, period, and component's masses.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 42 2162 Statistical data on the FG-67 sample of binaries
(stars of 0.9-1.5M☉ within 67pc)
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See also:
J/AJ/141/52 : Low-mass visual companions to nearby G-dwarfs
(Tokovinin, 2011)
J/MNRAS/389/925 : Triple and quadruple stars (Tokovinin, 2008)
J/A+A/450/681 : Companions to close spectroscopic binaries (Tokovinin+, 2006)
J/A+A/382/118 : Spectroscopic sub-systems in multiple stars
(Tokovinin+, 2002)
J/A+A/380/238 : Long-period companions of multiple stars (Shatsky, 2001)
J/A+AS/124/75 : Multiple star catalogue (MSC) (Tokovinin 1997-1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP0 Hipparcos number of primary component
8- 10 I3 --- L [1/121] Hierarchical level (1)
12- 16 A5 --- Type Type of system (2)
18- 22 F5.2 [d] logP ?=-9 Logarithm of orbital period log10(P/1day)
24- 27 F4.2 Msun M1 [0.05/4.4] System mass of the primary (3)
29- 32 F4.2 Msun M2 [0.02/2.8]?=0 System mass of the secondary (3)
34- 37 F4.2 Msun M1p [0.05/2.0] Mass of primary of (1) subsystem (3)
39- 42 F4.2 Msun M2p [0.02/1.7]?=0 Mass of primary of (2) susbsystem (3)
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Note (1): Hierarchies can be described by binary graphs or trees, also called
mobile diagrams (one example is shown in Figure 1). The position of each
pair in the tree is called level and is denoted here as L1, L11, etc.
The outermost (widest) pair is at the root of the tree, L1 (the root is
denoted by an asterisk in the parent designation). Inner pairs associated
with the primary and secondary components are at levels L11 and L12,
respectively, and this notation continues to deeper levels.
See Section 2.2 for more details.
Note (2): Types of system, as in Paper I (J/AJ/147/86):
S1 = Single-lined spectroscopic binary;
S2 = Double-lined spectroscopic binary;
s = Spectroscopic binary with variable radial velocity detected by Nordstrom
et al. 2004 (V/117; superseded by V/130), but with no orbit known;
s2 = Spectroscopic binary with double lines were seen in several spectra;
E = Eclipsing binary;
a = astrometric binary (acceleration detected)
A = astrometric binary with orbital solution derived in the original
Hipparcos catalog (I/239) or later (e.g., Goldin & Makarov,
2006ApJS..166..341G 2006ApJS..166..341G);
v = Visual binary;
V = Visual binary with orbit available in the 6th catalog of orbits of visual
binaries (VB6; Hartkopf & Mason, http://ad.usno.navy.mil/wds/orb6.html);
X = Optical (non-physical) binary
C = Real (physical) wide binary (completed with h, m, p, r qualifiers)
h = binary with constant relative position (criteria of physical relation)
m = common proper motion (criteria of physical relation)
p = matching photometric distance (criteria of physical relation)
r = matching radial velocity (criteria of physical relation)
Note (3): Masses are taken from the SYS table (Table5) of Paper I (Tokovinin
2014, J/AJ/147/86) and are estimated from absolute magnitudes using the
standard relation for main-sequence stars.
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History:
From electronic version of the journal
References:
Tokovinin, Paper I, 2014AJ....147...86T 2014AJ....147...86T, cat. J/AJ/147/86
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 11-Sep-2014