J/ApJ/787/154 Elemental abundances of solar sibling candidates (Ramirez+, 2014)
Elemental abundances of solar sibling candidates.
Ramirez I., Bajkova A.T., Bobylev V.V., Roederer I.U., Lambert D.L.,
Endl M., Cochran W.D., MacQueen P.J., Wittenmyer R.A.
<Astrophys. J., 787, 154 (2014)>
=2014ApJ...787..154R 2014ApJ...787..154R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, G-type ; Abundances ; Spectroscopy
Keywords: stars: abundances - stars: fundamental parameters - stars: general -
stars: individual: HD 162826 - stars: kinematics and dynamics
Abstract:
Dynamical information along with survey data on metallicity and in
some cases age have been used recently by some authors to search for
candidates of stars that were born in the cluster where the Sun
formed. We have acquired high-resolution, high signal-to-noise ratio
spectra for 30 of these objects to determine, using detailed elemental
abundance analysis, if they could be true solar siblings. Only two of
the candidates are found to have solar chemical composition. Updated
modeling of the stars' past orbits in a realistic Galactic potential
reveals that one of them, HD 162826, satisfies both chemical and
dynamical conditions for being a sibling of the Sun. Measurements of
rare-element abundances for this star further confirm its solar
composition, with the only possible exception of Sm. Analysis of
long-term high-precision radial velocity data rules out the presence
of hot Jupiters and confirms that this star is not in a binary system.
We find that chemical tagging does not necessarily benefit from
studying as many elements as possible but instead from identifying and
carefully measuring the abundances of those elements that show large
star-to-star scatter at a given metallicity. Future searches employing
data products from ongoing massive astrometric and spectroscopic
surveys can be optimized by acknowledging this fact.
Description:
We used the Tull coude spectrograph on the 2.7 m Harlan J. Smith
Telescope at McDonald Observatory (Tull et al. 1995PASP..107..251T 1995PASP..107..251T) to
observe most of our targets (23). All but three of them were observed
in 2012 December; the others were observed in 2013 March. The rest of
our targets (seven) have too-low declinations to be observed from
McDonald Observatory. Instead, they were observed using the Magellan
Inamori Kyocera Echelle (MIKE) spectrograph on the 6.5 m Telescope at
Las Campanas Observatory (Bernstein et al. 2003SPIE.4841.1694B 2003SPIE.4841.1694B) in
2013 April. Slit sizes were chosen so that the spectral resolution of
the data is about 60000 in the visible part of the spectrum. We
targeted a S/N per pixel of at least 200 at 6000 Å. Only one of our
targets (HD 46100) has a significantly lower S/N spectrum.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 30 127 Iron Line List
table4.dat 30 539 Line List For Elements Other Than Iron
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See also:
J/A+A/420/183 : Spectroscopic survey in solar neighborhood
(Allende Prieto+ 2004)
J/A+A/575/A51 : Line list for abundance determination in Sun siblings
(Liu+, 2015)
Byte-by-byte Description of file: table2.dat table4.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 0.1nm Wave Wavelength; Angstroms (1)
12- 15 F4.1 --- ID Species identifier (2)
17- 22 F6.4 eV ExPot Excitation Potential
24- 30 F7.4 [-] log(gf) Log of the oscillator strength
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Note (1): Lines where hyperfine structure was taken into account are listed as
one positive wavelength followed by a set of negative wavelengths
whose absolute values correspond to the HFS components.
Note (2): The number to the left of the decimal point indicates the atomic
number. The number to the right of the decimal point indicates the
ionization state, where "0" is neutral and "1" is singly ionized.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 30-Jun-2017