J/A+A/568/A26 SACY. V. Multiple systems (Elliott+, 2014)
Search for associations containing young stars (SACY).
V. Is multiplicity universal? Tight multiple systems.
Elliott P., Bayo A., Melo C.H.F., Torres C.A.O., Sterzik G.R., Quast M.
<Astron. Astrophys. 568, A26 (2014)>
=2014A&A...568A..26E 2014A&A...568A..26E
ADC_Keywords: Clusters, open ; Binaries, spectroscopic ;
Stars, pre-main sequence ; Radial velocities
Keywords: stars: formation - binaries: spectroscopic -
techniques: radial velocities - stars: pre-main sequence -
techniques: spectroscopic - stars: variables: T Tauri, Herbig Ae/Be
Abstract:
Dynamically undisrupted, young populations of stars are crucial in
studying the role of multiplicity in relation to star formation. Loose
nearby associations provide us with a great sample of close (<150pc)
pre-main sequence (PMS) stars across the very important age range
(∼5-70Myr) to conduct such research.
We characterize the short period multiplicity fraction of the search
for associations containing young stars (SACY) sample, accounting for
any identifiable bias in our techniques and present the role of
multiplicity fractions of the SACY sample in the context of star
formation.
Using the cross-correlation technique we identified double-lined and
triple-lined spectroscopic systems (SB2/SB3s), in addition to this we
computed radial velocity (RV) values for our subsample of SACY targets
using several epochs of fiber-fed extended range optical spectrograph
(FEROS) and ultraviolet and visual echelle spectrograph (UVES) data.
These values were used to revise the membership of each association
that was then combined with archival data to determine significant RV
variations across different data epochs characteristic of
multiplicity; single-lined multiple systems (SB1). Results: We
identified seven new multiple systems (SB1s: 5, SB2s: 2). We find no
significant difference between the short period multiplicity fraction
(Fm) of the SACY sample and that of close star-forming regions
(~-2Myr) and the field (Fm≤10%). These are seen both as a function
of age and as a function of primary mass, M1, in the ranges P
[1:200day] and M2 [0.08M☉-M1], respectively.
Our results are consistent with the picture of universal star
formation, when compared to the field and close star-forming regions
(SFRs). We comment on the implications of the relationship between
increasing multiplicity fraction with the primary mass within the
close companion range in relation to star formation.
Description:
Radial velocity values of approximately 250 pre-main sequence stars
were calculated from the cross-correlation technique using
high-resolution spectra from UVES and FEROS. We identified
single-lined spectroscopic binaries (SB1s) and double- and
triple-lined spectroscopic binaries (SB2s/SB3s) using these values
in combination with available catalogue data. We used the number of
identified systems to derive the fraction of spectroscopic binaries
in our sample and comment on the implications in the context of star
formation.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
aver-rv.dat 70 442 Radial velocities used in this work
sb2-rv.dat 98 33 Component radial velocity values for SB2/SB3 systems
members.dat 86 458 Membership list used in this work
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See also:
III/105 : CORAVEL Radial Velocities of Southern Stars (Andersen+ 1985)
III/249 : Stellar RV bibliographic catalog (Malaroda+, 2006)
III/252 : Pulkovo RV for 35493 HIP stars (Gontcharov, 2006)
III/272 : RAVE 4th data release (Kordopatis+, 2013)
J/A+A/460/695 : SACY. I. (Torres+, 2006)
J/A+A/508/833 : SACY. III. Li abundances (da Silva+, 2009)
J/MNRAS/431/1005 : IC 2391 and Argus young stars (de Silva+, 2013)
Byte-by-byte Description of file: aver-rv.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 22 A22 --- Name Star name
24- 25 I2 h RAh Right ascension (J2000.0)
27- 28 I2 min RAm Right ascension (J2000.0)
30- 33 F4.1 s RAs Right ascension (J2000.0)
35 A1 --- DE- Declination sign (J2000.0)
36- 37 I2 deg DEd Declination (J2000.0)
39- 40 I2 arcmin DEm Declination (J2000.0)
42- 43 I2 arcsec DEs Declination (J2000.0)
45- 46 I2 --- Nobs [1/11]? Number of observations
48- 53 F6.2 km/s RV Radial velocity
56- 59 F4.2 km/s e_RV ? Radial velocity error
60 A1 --- n_RV [AB] Reliability of RV error (1)
62 A1 --- r_RV [a-v] Reference for value used (2)
64 A1 --- Mmb [N] Member of association with new data (N=No)
66- 68 A3 --- Ass Association (G2)
70 A1 --- n_Name [B] Potential SB2 system (G1)
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Note (1): Uncertainties with value (A) or (B) are from de Bruijne and Eilers,
2012A&A...546A..61D 2012A&A...546A..61D, Cat. J/A+A/546/A61, with the following meaning:
A = The standard errors are generally reliable
B = Potential, small, uncorrected systematic errors
Note (2): References as follows:
a = Turon et al., 1993BICDS..43....5T 1993BICDS..43....5T, Cat. I/196
b = Ivanov, 2008KFNT...24..480I 2008KFNT...24..480I, Cat. IV/30
c = Andersen et al., 1985A&AS...59...15A 1985A&AS...59...15A, Cat. III/105
d = Reid et al., 1995AJ....110.1838R 1995AJ....110.1838R, Cat. III/198
e = Malaroda et al., 2006yCat.3249....0M 2006yCat.3249....0M, Cat, III/249
f = Gontcharov, 2006AstL...32..759G 2006AstL...32..759G, Cat III/252
g = Kharchenko et al., 2007AN....328..889K 2007AN....328..889K, Cat. J/AN/328/889
h = Siebert et al., 2011AJ....141..187S 2011AJ....141..187S, Cat. III/265
i = Rocha-Pinto et al., 2004A&A...423..517R 2004A&A...423..517R, Cat. J/A+A/423/517
j = Torres et al., 2006A&A...460..695T 2006A&A...460..695T, Cat. J/A+A/460/695
k = Maldonado et al., 2010A&A...521A..12M 2010A&A...521A..12M, Cat. J/A+A/521/A12
l = Casagrande et al., 2011A&A...530A.138C 2011A&A...530A.138C, Cat, J/A+A/530/A138
m = Jenkins et al., 2011A&A...531A...8J 2011A&A...531A...8J, Cat. J/A+A/531/A8
n = de Bruijne and Eilers, 2012A&A...546A..61D 2012A&A...546A..61D, Cat. J/A+A/546/A61
o = Lopez Marti et al., 2013A&A...551A..46L 2013A&A...551A..46L, Cat. J/A+A/551/A46
p = Strassmeier et al., 2000A&AS..142..275S 2000A&AS..142..275S, Cat. J/A+AS/142/275
q = White et al., 2007AJ....133.2524W 2007AJ....133.2524W, Cat. J/AJ/133/2425
r = Song et al., 2012AJ....144....8S 2012AJ....144....8S, Cat. J/AJ/144/8
s = Bobylev et al., 2006ARep...50..733B 2006ARep...50..733B, Cat. J/AZh/83/821
t = Kiraga, 2012AcA....62...67K 2012AcA....62...67K, Cat. J/AcA/62/67
u = Anderson & Francis, 2012AstL...38..331A 2012AstL...38..331A, Cat. V/137
v = Kordopatis et al., 2013AJ....146..134K 2013AJ....146..134K, Cat. III/272
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Byte-by-byte Description of file: sb2-rv.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 22 A22 --- Name Star name
24- 25 I2 h RAh Right ascension (J2000.0)
27- 28 I2 min RAm Right ascension (J2000.0)
30- 33 F4.1 s RAs Right ascension (J2000.0)
35 A1 --- DE- Declination sign (J2000.0)
36- 37 I2 deg DEd Declination (J2000.0)
39- 40 I2 arcmin DEm Declination (J2000.0)
42- 43 I2 arcsec DEs Declination (J2000.0)
45- 51 F7.1 d MJD Modified Julian date of observation
53- 55 A3 --- Ass Association (G2)
57- 60 F4.2 --- F2/1 ? Flux ratio of 2nd component to 1st
62- 65 F4.2 --- F3/1 ? Flux ratio of 3rd component to 1st
67- 71 F5.1 km/s RV1 Radial velocity of 1st component
73- 75 F3.1 km/s e_RV1 Error on RV1
77- 81 F5.1 km/s RV2 Radial velocity if 2nd component
83- 85 F3.1 km/s e_RV2 Error on RV2
87- 90 F4.1 km/s RV3 ? Radial velocity of 3rd component value
92- 94 F3.1 km/s e_RV3 ? Error on RV3
96 A1 --- Mmb [N] Member of association with new data (N=No)
98 A1 --- n_Name [A] Target not in Simbad (G1)
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Byte-by-byte Description of file: members.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 22 A22 --- Name Star name
24- 25 I2 h RAh Right ascension (J2000.0)
27- 28 I2 min RAm Right ascension (J2000.0)
30- 33 F4.1 s RAs Right ascension (J2000.0)
35 A1 --- DE- Declination sign (J2000.0)
36- 37 I2 deg DEd Declination (J2000.0)
39- 40 I2 arcmin DEm Declination (J2000.0)
42- 43 I2 arcsec DEs Declination (J2000.0)
45- 49 F5.2 mag Vmag Magnitude in V
51- 56 F6.1 pc Xpos X galactic position (distance)
58- 63 F6.1 pc Ypos Y galactic position (distance)
65- 69 F5.1 pc Zpos Z galactic position (distance)
71- 75 F5.1 pc D Distance [sqrt(X2+Y2+Z2)]
77- 78 A2 --- SpT Spectral type
80- 82 A3 --- Ass Association (G2)
84 A1 --- Mmb [N] Member of association with new data (N)=No
86 A1 --- n_Name [A] Target not in Simbad (G1)
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Global notes:
Note (G1): Notes as follows:
A = This target has no SIMBAD entry within 5arcsec at the date of publication
B = Potential SB2 system, see Appendix B.4 for details
Note (G2): the association are abbreviated as follows:
ABD = AB Dor (34±26pc, 50-100Myr)
ARG = Argos (106±51pc, 10-50Myr)
BPC = β Pic (31±21pc, 2-20Myr)
CAR = Carina (85±35pc, 10-35Myr)
COL = Columba (82±30pc, 15-70Myr)
ECH = ε Cha (108±9pc, 6-7Myr)
OCT = Octans (141±34pc, 10-30Myr)
THA = Tuc-Hor (48±7pc, 10-30Myr)
TWA = TW Hya (48±13pcn 5-10Myr)
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Acknowledgements:
Paul Elliott, pelliott(at)eso.org
References:
Torres et al., Paper I 2006A&A...460..695T 2006A&A...460..695T, Cat. J/A+A/460/695
Almeida Viana et al., Paper II 2009A&A...501..965A 2009A&A...501..965A
da Silva et al., Paper III 2009A&A...508..833D 2009A&A...508..833D, Cat. J/A+A/508/833
de Silva et al., Paper IV 2013MNRAS.431.1005D 2013MNRAS.431.1005D, Cat. J/MNRAS/431/1005
(End) Paul Elliott [ESO, Chile], Patricia Vannier [CDS] 23-Jun-2014