J/MNRAS/501/4329 [Fe/H] dependence of the wide-binary fraction (Hwang+, 2021)
The non-monotonic, strong metallicity dependence of the wide-binary fraction.
Hwang H.-C., Ting Y.-S., Schlaufman K.C., Zakamska N.L., Wyse R.F.G.
<Mon. Not. R. Astron. Soc., 501, 4329-4343 (2021)>
=2021MNRAS.501.4329H 2021MNRAS.501.4329H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Milky Way ; Proper motions ;
Parallaxes, trigonometric ; Abundances, [Fe/H] ;
Effective temperatures ; Radial velocities ; Optical
Keywords: stars: abundances - binaries: general - stars: formation -
stars: kinematics and dynamics
Abstract:
The metallicity dependence of the wide-binary fraction (WBF) IN
stellar populations plays a critical role in resolving the open
question of wide-binary formation. In this paper, we investigate the
metallicity ([Fe/H]) and age dependence of the WBF (binary separations
between 103 and 104au) for field F and G dwarfs within 500pc by
combining their metallicity and radial velocity measurements from
LAMOST Data Release 5 (DR5) with the astrometric information from Gaia
DR2. We show that the WBF strongly depends on the metallicity: as
metallicity increases, the WBF first increases, peaks at [Fe/H]∼0, and
then decreases at the high-metallicity end. The WBF at [Fe/H]=0 is
about two times larger than that at [Fe/H]=-1 and +0.5. This
metallicity dependence is dominated by the thin-disc stars. Using
stellar kinematics as a proxy of stellar age, we show that younger
stars have a higher WBF at fixed metallicity close to solar. We
propose that multiple formation channels are responsible for the
metallicity and age dependence. In particular, the positive
metallicity correlation at [Fe/H]<0 and the age dependence may be due
to the denser formation environments and higher mass clusters at
earlier times. The negative metallicity correlation at [Fe/H]>0 can be
inherited from the similar metallicity dependence of close binaries,
and radial migration may play a role in enhancing the WBF around the
solar metallicity.
Description:
Our sample is selected from LAMOST (Deng et al. 2012RAA....12..735D 2012RAA....12..735D;
Zhao et al. 2012RAA....12..723Z 2012RAA....12..723Z). In its final data release of the
LAMOST Phase I (2011-2017) survey, LAMOST DR5 has released optical
(3700-9000Å) low-resolution spectra (R∼1800) for about 10 million
stars, providing a rich data set for Galactic archaeology.
We use the A/F/G/K stars catalogue from LAMOST DR5 (v3). Its
metallicity ([Fe/H]) is derived from the LAMOST Stellar Parameter
pipeline (LASP; Wu et al. 2011A&A...525A..71W 2011A&A...525A..71W, Cat. J/A+A/525/A71,
2011RAA....11..924W 2011RAA....11..924W, Cat. J/other/RAA/11.924) and the data-driven Payne
pipeline (DD-Payne; Xiang et al. 2019ApJS..245...34X 2019ApJS..245...34X, Cat.
J/ApJS/245/34).
We use Gaia DR2 to search for the comoving companions around the
LAMOST stars. Gaia DR2 provides broad-filter G-band magnitudes,
blue-band BP magnitudes, red-band RP magnitudes, sky positions,
parallaxes, and proper motions for 1.33 billion objects and radial
velocities for 7 million stars (Gaia Collaboration
2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345), resulting in an unprecedented data
set for the phase-space information of the Milky Way.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
wblasp.dat 292 7671 LASP wide-binary catalogue
wbpayne.dat 288 7266 DD-Payne wide-binary catalogue
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
J/A+A/525/A71 : Atmospheric parameters for 1273 stars (Wu+, 2011)
J/other/RAA/11.924 : Atmospheric parameters for 771 stars (Wu+, 2011)
J/ApJS/245/34 : Abundances for 6 million stars from LAMOST DR5
(Xiang+, 2019)
Byte-by-byte Description of file: wblasp.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier of the primary
LAMOST star
21- 35 F15.11 deg RAdeg Right ascension (ICRS) at Ep=2015.5 of the
primary LAMOST star
37- 50 F14.11 deg DEdeg Declination (ICRS) at Ep=2015.5 of the
primary LAMOST star
52- 58 F7.4 mas plx Parallax of the primary LAMOST star
60- 65 F6.4 mas e_plx Error on plx
67- 74 F8.3 mas/yr pmRA Proper motion in right ascension of the
primary LAMOST star
76- 80 F5.3 mas/yr e_pmRA Error on pmRA
82- 89 F8.3 mas/yr pmDE Proper motion in declination of the primary
LAMOST star
91- 95 F5.3 mas/yr e_pmDE Error on pmDE
97- 105 F9.6 mag Gmag Gaia DR2 G-band magnitude of the primary
LAMOST star
107- 125 A19 --- LAMOST LAMOST designation from the LASP catalogue
127- 132 F6.3 [-] [Fe/H] Iron abundance of the LAMOST star measured
by LASP
134- 140 F7.2 K Teff Effective temperature of the LAMOST star
measured by LASP
142- 146 F5.3 [cm/s2] logg Surface gravity of the LAMOST star measured
by LASP
148- 156 F9.5 km/s vtot Total velocity with respect to the local
standard of rest
158- 167 F10.8 kpc zmax Maximum Galactic height of the Galactic
orbit
169- 187 I19 --- GaiaDR22 Gaia DR2 source identifier of the companion
189- 203 F15.11 deg RA2deg Right ascension (ICRS) at Ep=2015.5 of the
companion
205- 218 F14.11 deg DE2deg Declination (ICRS) at Ep=2015.5 of the
companion
220- 226 F7.4 mas plx2 Parallax of the companion
228- 233 F6.4 mas e_plx2 Error on plx2
235- 242 F8.3 mas/yr pmRA2 Proper motion in right ascension of the
companion
244- 248 F5.3 mas/yr e_pmRA2 Error on pmRA2
250- 257 F8.3 mas/yr pmDE2 Proper motion in declination of the
companion
259- 263 F5.3 mas/yr e_pmDE2 Error on pmDE2
265- 273 F9.6 mag Gmag2 Gaia DR2 G-band magnitude of the companion
275- 281 F7.2 AU Sep Physical separation of the wide binary
283- 292 F10.7 km/s RV Relative velocity of the wide binary
projected on the sky
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Byte-by-byte Description of file: wbpayne.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier of the primary
LAMOST star
21- 35 F15.11 deg RAdeg Right ascension (ICRS) at Ep=2015.5 of the
primary LAMOST star
37- 50 F14.11 deg DEdeg Declination (ICRS) at Ep=2015.5 of the
primary LAMOST star
52- 58 F7.4 mas plx Parallax of the primary LAMOST star
60- 65 F6.4 mas e_plx Error on plx
67- 74 F8.3 mas/yr pmRA Proper motion in right ascension of the
primary LAMOST star
76- 80 F5.3 mas/yr e_pmRA Error on pmRA
82- 89 F8.3 mas/yr pmDE Proper motion in declination of the primary
LAMOST star
91- 95 F5.3 mas/yr e_pmDE Error on pmDE
97- 105 F9.6 mag Gmag Gaia DR2 G-band magnitude of the primary
LAMOST star
107- 121 A15 --- Payne Star ID from the DD-Payne catalogue
123- 128 F6.3 [-] [Fe/H] Iron abundance of the LAMOST star measured
by DD-Payne
130- 136 F7.2 K Teff Effective temperature of the LAMOST star
measured by DD-Payne
138- 142 F5.3 [cm/s2] logg Surface gravity of the LAMOST star measured
by DD-Payne
144- 152 F9.5 km/s vtot Total velocity with respect to the local
standard of rest
154- 163 F10.8 kpc zmax Maximum Galactic height of the Galactic
orbit
165- 183 I19 --- GaiaDR22 Gaia DR2 source identifier of the companion
185- 199 F15.11 deg RA2deg Right ascension (ICRS) at Ep=2015.5 of the
companion
201- 214 F14.11 deg DE2deg Declination (ICRS) at Ep=2015.5 of the
companion
216- 222 F7.4 mas plx2 Parallax of the companion
224- 229 F6.4 mas e_plx2 Error on plx2
231- 238 F8.3 mas/yr pmRA2 Proper motion in right ascension of the
companion
240- 244 F5.3 mas/yr e_pmRA2 Error on pmRA2
246- 253 F8.3 mas/yr pmDE2 Proper motion in declination of the
companion
255- 259 F5.3 mas/yr e_pmDE2 Error on pmDE2
261- 269 F9.6 mag Gmag2 Gaia DR2 G-band magnitude of the companion
271- 277 F7.2 AU Sep Physical separation of the wide binary
279- 288 F10.7 km/s RV Relative velocity of the wide binary
projected on the sky
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 19-Oct-2023