J/MNRAS/492/1164 Abundances of Gaia DR2 wide binaries (Hawkins+, 2020)
Identical or fraternal twins? The chemical homogeneity of wide binaries
from Gaia DR2.
Hawkins K., Lucey M., Ting Y.-S., Ji A., Katzberg D., Thompson M.,
El-Badry K., Teske J., Nelson T., Carrillo A.
<Mon. Not. R. Astron. Soc., 492, 1164-1179 (2020)>
=2020MNRAS.492.1164H 2020MNRAS.492.1164H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Abundances ; Effective temperatures ;
Spectra, optical
Keywords: stars: abundances - binaries: general -
stars: kinematics and dynamics - stars: late-type
Abstract:
One of the high-level goals of Galactic archaeology is chemical
tagging of stars across the Milky Way to piece together its assembly
history. For this to work, stars born together must be uniquely
chemically homogeneous. Wide binary systems are an important
laboratory to test this underlying assumption. Here we present the
detailed chemical abundance patterns of 50 stars across 25 wide binary
systems comprised of main-sequence stars of similar spectral type
identified in Gaia DR2 with the aim of quantifying their level of
chemical homogeneity. Using high-resolution spectra obtained with
McDonald Observatory, we derive stellar atmospheric parameters and
precise detailed chemical abundances for light/odd-Z (Li, C, Na, Al,
Sc, V, Cu), alpha (Mg, Si, Ca), Fe-peak (Ti, Cr, Mn, Fe, Co, Ni, Zn),
and neutron capture (Sr, Y, Zr, Ba, La, Nd, Eu) elements. Results
indicate that 80% (20 pairs) of the systems are homogeneous in [Fe/H]
at levels below 0.02dex. These systems are also chemically
homogeneous in all elemental abundances studied, with offsets and
dispersions consistent with measurement uncertainties. We also find
that wide binary systems are far more chemically homogeneous than
random pairings of field stars of similar spectral type. These results
indicate that wide binary systems tend to be chemically homogeneous
but in some cases they can differ in their detailed elemental
abundances at a level of [X/H]∼0.10dex, overall implying chemical
tagging in broad strokes can work.
Description:
Stellar parameters and abundances for 50 stars in 25 wide binaries
observed with McDonald Observatory in 2019.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 96 50 Observational properties of wide binary systems
table3.dat 573 50 Stellar parameter and chemical abundance ratios
of observed wide binary system
tablea1.dat 80 12617 Line-by-line abundance information
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/157/78 : Double + multiple star systems from GaiaDR2
(Jimenez-Esteban+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21- 28 F8.4 deg RAdeg Right ascension (ICRS) at Ep=2015.5
30- 36 F7.4 deg DEdeg Declination (ICRS) at Ep=2015.5
38- 42 A5 --- Name Associated wide binary component name
44- 49 F6.2 km/s RV Radial velocity measured in our optical spectra
51- 54 F4.2 km/s e_RV rms uncertainty on RV
56- 58 I3 pix-1 SNR SNR, measured in at the continuum level at
∼5350Å, of our optical spectra
60- 64 F5.2 mas Plx Gaia DR2 parallax
66- 72 F7.2 mas/yr pmRA* Gaia DR2 proper motion in RA, pmRA*cosDE
74- 80 F7.2 mas/yr pmDE Gaia DR2 proper motion in DE
82- 86 F5.2 mag Gmag Gaia DR2 G magnitude
88- 91 F4.2 mag BP-RP Gaia DR2 BP-RP colour index
93- 96 I4 K Teffph Photometric effective temperature
(Andrae et al., 2018A&A...616A...8A 2018A&A...616A...8A)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 19 I19 [-] GaiaDR2 Gaia DR2 Source ID
21- 25 A5 --- Name Associated wide binary component name
27- 30 I4 K Teff Effective temperature
32- 34 I3 K e_Teff rms uncertainty on Teff
36- 39 F4.2 [cm/s2] logg Surface gravity
41- 44 F4.2 [cm/s2] e_logg rms uncertainty on logg
46- 50 F5.2 [-] [Fe/H] Metallicity
52- 55 F4.2 [-] e_[Fe/H] rms uncertainty on [Fe/H]
57- 60 F4.2 km/s vmicro Micro-turbulent velocity
62- 65 F4.2 km/s e_vmicro rms uncertainty on vmicro
67- 71 F5.2 [-] [Li/H] ? Abundance [Li/H]
73- 76 F4.2 [-] e_[Li/H] ? Error on [Li/H]
78- 81 F4.2 [-] e_[Li/H]tot ? Total error on [Li/H]
83- 86 F4.2 --- o_[Li/H] ?=0 Number of line for [Li/H]
88- 92 F5.2 [-] [C/H] Abundance [C/H]
94- 97 F4.2 [-] e_[C/H] Error on [C/H]
99-102 F4.2 [-] e_[C/H]tot Total error on [C/H]
104-108 F5.2 --- o_[C/H] Number of line for [C/H]
110-114 F5.2 [-] [Na/H] Abundance [Na/H]
116-119 F4.2 [-] e_[Na/H] Error on [Na/H]
121-124 F4.2 [-] e_[Na/H]tot Total error on [Na/H]
126-129 F4.2 --- o_[Na/H] Number of line for [Na/H]
131-135 F5.2 [-] [Mg/H] Abundance [Mg/H]
137-140 F4.2 [-] e_[Mg/H] Error on [Mg/H]
142-145 F4.2 [-] e_[Mg/H]tot Total error on [Mg/H]
147-150 F4.2 --- o_[Mg/H] Number of line for [Mg/H]
152-156 F5.2 [-] [Al/H] ? Abundance [Al/H]
158-161 F4.2 [-] e_[Al/H] ? Error on [Al/H]
163-166 F4.2 [-] e_[Al/H]tot ? Total error on [Al/H]
168-171 F4.2 --- o_[Al/H] ?=0 Number of line for [Al/H]
173-177 F5.2 [-] [Si/H] Abundance [Si/H]
179-182 F4.2 [-] e_[Si/H] Error on [Si/H]
184-187 F4.2 [-] e_[Si/H]tot Total error on [Si/H]
189-193 F5.2 --- o_[Si/H] Number of line for [Si/H]
195-199 F5.2 [-] [Ca/H] Abundance [Ca/H]
201-204 F4.2 [-] e_[Ca/H] Error on [Ca/H]
206-209 F4.2 [-] e_[Ca/H]tot Total error on [Ca/H]
211-215 F5.2 --- o_[Ca/H] Number of line for [Ca/H]
217-221 F5.2 [-] [Sc/H] Abundance [Sc/H]
223-226 F4.2 [-] e_[Sc/H] Error on [Sc/H]
228-231 F4.2 [-] e_[Sc/H]tot Total error on [Sc/H]
233-237 F5.2 --- o_[Sc/H] Number of line for [Sc/H]
239-243 F5.2 [-] [Ti/H] Abundance [Ti/H]
245-248 F4.2 [-] e_[Ti/H] Error on [Ti/H]
250-253 F4.2 [-] e_[Ti/H]tot Total error on [Ti/H]
255-259 F5.2 --- o_[Ti/H] Number of line for [Ti/H]
261-265 F5.2 [-] [V/H] ? Abundance [V/H]
267-270 F4.2 [-] e_[V/H] ? Error on [V/H]
272-275 F4.2 [-] e_[V/H]tot ? Total error on [V/H]
277-280 F4.2 --- o_[V/H] ?=0 Number of line for [V/H]
282-286 F5.2 [-] [Cr/H] Abundance [Cr/H]
288-291 F4.2 [-] e_[Cr/H] Error on [Cr/H]
293-296 F4.2 [-] e_[Cr/H]tot Total error on [Cr/H]
298-302 F5.2 --- o_[Cr/H] Number of line for [Cr/H]
304-308 F5.2 [-] [Mn/H] Abundance [Mn/H]
310-313 F4.2 [-] e_[Mn/H] Error on [Mn/H]
315-318 F4.2 [-] e_[Mn/H]tot Total error on [Mn/H]
320-324 F5.2 --- o_[Mn/H] Number of line for [Mn/H]
326-329 F4.2 [-] e_[Fe/H]tot Total error on [Fe/H]
331-336 F6.2 --- o_[Fe/H] Number of line for [Fe/H]
338-342 F5.2 [-] [Co/H] ? Abundance [Co/H]
344-347 F4.2 [-] e_[Co/H] ? Error on [Co/H]
349-352 F4.2 [-] e_[Co/H]tot ? Total error on [Co/H]
354-357 F4.2 --- o_[Co/H] ?=0 Number of line for [Co/H]
359-363 F5.2 [-] [Ni/H] Abundance [Ni/H]
365-368 F4.2 [-] e_[Ni/H] Error on [Ni/H]
370-373 F4.2 [-] e_[Ni/H]tot Total error on [Ni/H]
375-379 F5.2 --- o_[Ni/H] Number of line for [Ni/H]
381-385 F5.2 [-] [Cu/H] Abundance [Cu/H]
387-390 F4.2 [-] e_[Cu/H] Error on [Cu/H]
392-395 F4.2 [-] e_[Cu/H]tot Total error on [Cu/H]
397-400 F4.2 --- o_[Cu/H] Number of line for [Cu/H]
402-406 F5.2 [-] [Zn/H] ? Abundance [Zn/H]
408-411 F4.2 [-] e_[Zn/H] ? Error on [Zn/H]
413-416 F4.2 [-] e_[Zn/H]tot ? Total error on [Zn/H]
418-421 F4.2 --- o_[Zn/H] ?=0 Number of line for [Zn/H]
423-427 F5.2 [-] [Sr/H] ? Abundance [Sr/H]
429-432 F4.2 [-] e_[Sr/H] ? Error on [Sr/H]
434-437 F4.2 [-] e_[Sr/H]tot ? Total error on [Sr/H]
439-442 F4.2 --- o_[Sr/H] ?=0 Number of line for [Sr/H]
444-448 F5.2 [-] [Y/H] Abundance [Y/H]
450-453 F4.2 [-] e_[Y/H] Error on [Y/H]
455-458 F4.2 [-] e_[Y/H]tot Total error on [Y/H]
460-463 F4.2 --- o_[Y/H] Number of line for [Y/H]
465-469 F5.2 [-] [Zr/H] ? Abundance [Zr/H]
471-474 F4.2 [-] e_[Zr/H] ? Error on [Zr/H]
476-479 F4.2 [-] e_[Zr/H]tot ? Total error on [Zr/H]
481-484 F4.2 --- o_[Zr/H] ?=0 Number of line for [Zr/H]
486-490 F5.2 [-] [Ba/H] Abundance [Ba/H]
492-495 F4.2 [-] e_[Ba/H] Error on [Ba/H]
497-500 F4.2 [-] e_[Ba/H]tot Total error on [Ba/H]
502-505 F4.2 --- o_[Ba/H] Number of line for [Ba/H]
507-511 F5.2 [-] [La/H] ? Abundance [La/H]
513-516 F4.2 [-] e_[La/H] ? Error on [La/H]
518-521 F4.2 [-] e_[La/H]tot ? Total error on [La/H]
523-526 F4.2 --- o_[La/H] ?=0 Number of line for [La/H]
528-532 F5.2 [-] [Nd/H] ? Abundance [Nd/H]
534-537 F4.2 [-] e_[Nd/H] ? Error on [Nd/H]
539-542 F4.2 [-] e_[Nd/H]tot ? Total error on [Nd/H]
544-547 F4.2 --- o_[Nd/H] ?=0 Number of line for [Nd/H]
549-553 F5.2 [-] [Eu/H] ? Abundance [Eu/H]
555-558 F4.2 [-] e_[Eu/H] ? Error on [Eu/H]
560-563 F4.2 [-] e_[Eu/H]tot ? Total error on [Eu/H]
565-567 F3.1 --- o_[Eu/H] ?=0 Number of line for [Eu/H]
569-573 A5 --- RandomPair The assigned random pair
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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- 5 A5 --- Name Wide binary component name
7- 11 A5 --- El Element
13- 19 F7.2 --- lambda Wavelength
21- 26 F6.3 [-] loggf Oscillator Strength
28- 66 A39 --- r_loggf Reference for loggf
68- 73 F6.3 eV EP Excitation Potential
75- 80 F6.3 [-] logeps Abundance
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Acknowledgements:
Keith Hawkins, keithhawkins(at)utexas.edu
(End) Patricia Vannier [CDS] 22-May-2020