J/ApJ/704/531 The coevality of young binary systems (Kraus+, 2009)
The coevality of young binary systems.
Kraus A.L., Hillenbrand L.A.
<Astrophys. J., 704, 531-547 (2009)>
=2009ApJ...704..531K 2009ApJ...704..531K
ADC_Keywords: Stars, double and multiple ; Stars, ages ; Stars, masses ;
Stars, pre-main sequence ; Spectral types
Keywords: binaries: general - Hertzsprung-Russell (HR) diagram - open clusters
and associations: individual (Taurus-Auriga) - stars: evolution -
stars: fundamental parameters - stars: pre-main sequence
Abstract:
Multiple star systems are commonly assumed to form coevally; they thus
provide the anchor for most calibrations of stellar evolutionary
models. In this paper, we study the binary population of the
Taurus-Auriga association, using the component positions in an HR
diagram in order to quantify the frequency and degree of coevality in
young binary systems. After identifying and rejecting the systems that
are known to be affected by systematic errors (due to further
multiplicity or obscuration by circumstellar material), we find that
the relative binary ages, |Δlogτ|, have an overall
dispersion σ|Δlogτ|∼0.40dex.
Description:
The accurate determination of stellar parameters requires spatially
and/or spectrally resolved observations that are not polluted by light
from companions; our sample is comprised of all known Taurus binary
systems that have spectral types and flux ratios for at least two
components. Most sample members have been observed with Hubble Space
Telescope (HST), ground-based adaptive optics, or echelle
spectrographs. We list the observed properties of our sample members
in Table 1, along with the references used to infer spectral types,
extinctions, and fluxes.
We list our sample of apparently single stars in Table A1, including
all of the references for our adopted parameters (singleness, spectral
type, and extinction). We based our sample on the compilation of all
Taurus members that we originally described in Kraus & Hillenbrand
2007, Cat. J/ApJ/662/413), and then we omitted all stars that did not
have at least one observation at high angular resolution.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 108 73 Binary sample: observed and inferred properties
table2.dat 114 73 Derived ages and masses
tablea1.dat 131 121 Single-star sample: observed properties
refs.dat 65 51 References
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See also:
J/A+A/519/A83 : T Tau stars toward the Taurus-Auriga region (Takita+ 2010)
J/ApJ/703/1964 : Spectra of three nearby star-forming regions (Furlan+, 2009)
J/ApJ/703/1511 : Wide binaries in Taurus and Upper Sco (Kraus+, 2009)
J/ApJ/662/413 : 2MASS survey of wide multiplicity in 3 associations (Kraus+,
2007)
J/AJ/132/2665 : QUEST2 BRI photometry of Taurus-Auriga PMS (Slesnick+, 2006)
J/A+A/446/485 : New very low-mass members in Taurus (Guieu+, 2006)
J/ApJ/647/1180 : Infrared photometry of Taurus SFR (Luhman+, 2006)
J/ApJ/636/932 : Mid-infrared survey of T Tauri stars (McCabe+, 2006)
J/ApJ/645/676 : Spatial distribution of brown dwarfs in Taurus (Luhman+, 2006)
J/ApJ/593/1093 : IC 348 membership (Luhman+, 2003)
J/ApJ/581/1194 : Taurus-Auriga PMS stars ages and Teff (Palla+, 2002)
J/A+A/337/403 : Low-mass stars evolutionary models (Baraffe+ 1998)
J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Name
14 I1 h RAh Hour of right ascension (J2000)
16- 17 I2 min RAm Minute of right ascension (J2000)
19- 23 F5.2 s RAs Second of right ascension (J2000)
25 A1 --- DE- Sign of declination (J2000)
26- 27 I2 deg DEd Degree of declination (J2000)
29- 30 I2 arcmin DEm Arcminute of declination (J2000)
32- 35 F4.1 arcsec DEs Arcsecond of declination (J2000)
37- 38 A2 --- SB Spectroscopic binary ("Sep" is null)
40- 46 F7.1 mas Sep ? Separation
48- 51 F4.1 mas e_Sep ? Uncertainty in Sep
53 A1 --- n_Flux [JHK] Band in which "Flux" is measured
55- 59 F5.2 mag Flux 2MASS magnitude in "Band"
61- 65 A5 --- SpT MK spectral type
67- 70 F4.2 --- e_SpT Spectral type uncertainty
72- 75 F4.1 mag Av Extinction
77- 80 I4 K Teff Effective temperature
82- 84 I3 K e_Teff Teff uncertainty
86- 90 F5.2 mag Mbol Bolometric magnitude
92- 93 A2 --- Warm [Y/N? ] Warm disk?
95-108 A14 --- Ref References (see refs.dat file)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Name
14- 18 F5.3 Msun Mass ? Adopted inferred mass from our hybrid system
20- 24 F5.3 Msun E_Mass ? Positive error in Mass
26- 30 F5.3 Msun e_Mass ? Negative error in Mass
32 A1 --- l_logtau Limit flag on logtau
33- 36 F4.2 [yr] logtau Adopted inferred age from our hybrid system
38- 41 F4.2 [yr] E_logtau ? Positive error in logtau
43- 46 F4.2 [yr] e_logtau ? Negative error in logtau
48- 52 F5.3 Msun MassL ? Mass from the Lyon models (1)
54- 58 F5.3 Msun E_MassL ? Positive error in MassL
60- 64 F5.3 Msun e_MassL ? Negative error in MassL
66 A1 --- l_logtauL Limit flag on logtauL
67- 70 F4.2 [yr] logtauL Age from the Lyon models (1)
72- 75 F4.2 [yr] E_logtauL ? Positive error in logtauL
77- 80 F4.2 [yr] e_logtauL ? Negative error in logtauL
82- 86 F5.3 Msun MassD ? Mass from the DM97 model (2)
88- 92 F5.3 Msun E_MassD ? Positive error in MassD
94- 98 F5.3 Msun e_MassD ? Negative error in MassD
100 A1 --- l_logtauD Limit flag on logtauD
101-104 F4.2 [yr] logtauD Age from the DM97 model (2)
106-109 F4.2 [yr] E_logtauD ? Positive error in logtauD
111-114 F4.2 [yr] e_logtauD ? Negative error in logtauD
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Note (1): (Baraffe et al. 1998, Cat. J/A+A/337/403; Chabrier et al.
2000ApJ...542..464C 2000ApJ...542..464C)
Note (2): D'Antona & Mazzitelli (1997MmSAI..68..807D 1997MmSAI..68..807D)
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Name Star name
25 I1 h RAh Hour of right ascension (J2000)
27- 28 I2 min RAm Minute of right ascension (J2000)
30- 34 F5.2 s RAs Second of right ascension (J2000)
36 A1 --- DE- Sign of declination (J2000)
37- 38 I2 deg DEd Degree of declination (J2000)
40- 41 I2 arcmin DEm Arcminute of declination (J2000)
43- 46 F4.1 arcsec DEs Arcsecond of declination (J2000)
48- 52 F5.2 mag Jmag 2MASS J-band magnitude
54- 58 A5 --- SpT MK spectral type
60- 63 F4.2 --- e_SpT SpT uncertainty
65- 68 F4.1 mag Av Extinction
70- 73 I4 K Teff Effective temperature
75- 77 I3 K e_Teff Teff uncertainty
79- 83 F5.2 mag Mbol Bolometric mass
85 A1 --- l_Mass [-] Nonphysical mass (1)
86- 90 F5.3 Msun Mass Mass
92- 96 F5.3 Msun E_Mass Positive error in Mass
98-102 F5.3 Msun e_Mass Negative error in Mass
104 A1 --- l_logtau [-] Nonphysical age (1)
105-108 F4.2 [yr] logtau Age
110-114 F5.2 [yr] E_logtau Positive error in Age
116-120 F5.2 [yr] e_logtau Negative error in Age
122-131 A10 --- Ref References (see refs.dat file)
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Note (1): Some systems that sit extremely high or low in the HR diagram exceed
the limits of the models and have nonphysical derived quantities
(i.e., negative masses).
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode Bibcode
24- 44 A21 --- Aut Authors
46- 65 A20 --- Comm Comment
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 04-Nov-2011