J/A+A/570/A22 Heavy elements in old very metal-rich stars (Trevisan+, 2014)
Heavy elements in old very metal-rich stars.
Trevisan M., Barbuy B.
<Astron. Astrophys. 570, A22 (2014)>
=2014A&A...570A..22T 2014A&A...570A..22T
ADC_Keywords: Abundances ; Stars, nearby ; Stars, late-type
Keywords: stars: abundances - stars: atmospheres - solar neighbourhood
Abstract:
We studied a sample of high proper motion, old and metal-rich dwarf
stars, selected from the NLTT catalogue. The low pericentric distances
and eccentric orbits of these solar neighbourhood stars indicate that
they might have originated in the inner parts of the Galaxy. Chemical
tagging can probe the formation history of stellar populations. To
identify the origin of a sample of 71 very metal-rich dwarf stars, we
derive the abundances of the neutron-capture elements Y, Ba, La, and
Eu. The abundances of Y, La, Ba, and Eu vs. Fe, O, and Mg as reference
elements, as well as their kinematics, suggest that our sample of old
metal-rich dwarf stars is clearly distinct from the thin disk. They
could be old inner thin-disk stars, as suggested previously, or bulge
stars. In either cases they would have migrated from the inner parts
of the Galaxy to the solar neighbourhood.
Description:
The spectroscopic analysis is based on optical high-resolution echelle
spectra obtained with the FEROS spectrograph at the ESO 1.52-m
Telescope at La Silla, Chile. The abundances of Y, Ba, La, and Eu were
derived for 71 very metal-rich dwarf stars through LTE analysis,
employing the MARCS model atmospheres.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
abunds.dat 66 71 Stellar abundances in Fe, Y, Ba, La, Eu.
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See also:
I/98 : NLTT Catalogue (Luyten, 1979)
J/ApJ/637/1102 : Lick indices for metal-rich stars (Robinson+, 2006)
J/ApJS/169/430 : Atmospheric param. of 1907 metal-rich stars (Robinson+, 2007)
J/A+A/535/A42 : Metal rich stars in solar neighbourhood (Trevisan+, 2011)
Byte-by-byte Description of file: abunds.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Star name
12- 17 F6.2 [Sun] [Fe/H] Abundance of Fe (1)
18- 22 F5.2 [Sun] e_[Fe/H] Error in abundance of Fe
23- 28 F6.2 [Sun] [Y/Fe] Y-to-Fe abundance ratio (1)
29- 33 F5.2 [Sun] e_[Y/Fe] ? Error in the Y-to-Fe ratio
34- 39 F6.2 [Sun] [Ba/Fe] Ba-to-Fe abundance ratio (1)
40- 44 F5.2 [Sun] e_[Ba/Fe] Error in the Ba-to-Fe ratio
45- 50 F6.2 [Sun] [La/Fe] La-to-Fe abundance ratio (1)
51- 55 F5.2 [Sun] e_[La/Fe] ? Error in the La-to-Fe ratio
56- 61 F6.2 [Sun] [Eu/Fe] ? Eu-to-Fe abundance ratio (1)
62- 66 F5.2 [Sun] e_[Eu/Fe] ? Error in the Eu-to-Fe ratio
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Note (1): the adopted solar abundances logε(Z)☉ are:
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El Z Ab.☉
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Fe 26 7.50
Y 39 2.24
Ba 56 2.13
La 57 1.22
Eu 63 0.51
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Acknowledgements:
Marina Trevisan, marina.trevisan(at)das.inpe.br
(End) Marina Trevisan [INPE, Brazil], Emmanuelle Perret [CDS] 13-Aug-2014