J/A+A/572/A33 Abundances from Gaia-ESO Survey (Mikolaitis+, 2014)
The Gaia-ESO Survey: the chemical structure of the Galactic discs from the
first internal data release.
Mikolaitis S., Hill V., Recio-Blanco A., de Laverny P., Allende Prieto C.,
Kordopatis G., Tautvaisiene G., Romano D., Gilmore G., Randich S.,
Feltzing S., Micela G., Vallenari A., Alfaro E.J., Bensby T., Bragaglia A.,
Flaccomio E., Lanzafame A.C., Pancino E., Smiljanic R., Bergemann M.,
Carraro G., Costado M.T., Damiani F., Hourihane A., Jofre P., Lardo C.,
Magrini L., Maiorca E., Morbidelli L., Sbordone L., Sousa S.G., Worley C.C.,
Zaggia S.
<Astron. Astrophys. 572, A33 (2014)>
=2014A&A...572A..33M 2014A&A...572A..33M
ADC_Keywords: Stars, normal ; Spectroscopy ; Abundances
Keywords: Galaxy: disc - Galaxy: stellar content - techniques: spectroscopic
Abstract:
Most high-resolution spectroscopic studies of the Galactic discs were
mostly confined to objects in the solar vicinity. Here we aim at
enlarging the volume in which individual chemical abundances are used
to characterise both discs, using the first internal data release of
the Gaia-ESO survey. We derive and discuss the abundances of eight
elements (Mg, Al, Si, Ca, Ti, Fe, Cr, Ni, and Y). The trends of these
elemental abundances with iron are very similar to those in the solar
neighbourhood. We find a natural division between α-rich and
α-poor stars, best seen in the bimodality of the [Mg/M]
distributions in bins of metallicity, which we attribute to thick- and
thin-disc sequences, respectively. With the possible exception of Al,
the observed dispersion around the trends is well described by the
expected errors, leaving little room for astrophysical dispersion.
Using previously derived distances from Recio-Blanco et al.
(2014A&A...567A...5R 2014A&A...567A...5R), we further find that the thick-disc is more
extended vertically and is more centrally concentrated towards the
inner Galaxy than the thin-disc, which indicates a shorter
scale-length. We derive the radial and vertical gradients in
metallicity, iron, four α-element abundances, and Al for the two
populations, taking into account the identified correlation between
RGC and |Z|. Radial metallicity gradient is found in the thin disc.
The positive radial individual [α/M] gradients found are at
variance from the gradients observed in the RAVE survey. The thin disc
also hosts a negative vertical metallicity gradient, accompanied by
positive individual [α/M] and [Al/M] gradients. The thick-disc,
presents no radial metallicity gradient, a shallower vertical
metallicity gradient than the thin-disc, an α-elements-to-iron
radial gradient in the opposite sense than that of the thin disc, and
positive vertical individual [α/M] and [Al/M] gradients.
Description:
Table2 contains chemical abundances of 1916 stars from GES DR1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 156 1916 Abundances of 1916 stars
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See also:
I/324 : The Initial Gaia Source List (IGSL) (Smart, 2013)
J/MNRAS/426/1767 : Gaia spectrophotometric standard stars I. (Pancino+, 2012)
J/A+A/552/A64 : Gaia-RVS standards (Soubiran+, 2013)
J/A+A/566/A98 : The Gaia Benchmark Stars - Library (Blanco-Cuaresma+, 2014)
J/A+A/565/A11 : Gaia photometry for white dwarfs (Carrasco+, 2014)
J/A+A/564/A133 : Gaia FGK benchmark stars: metallicity (Jofre+, 2014)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID [1/1916] Identification number
6- 21 A16 --- CName Target Name in the Gaia-ESO archive,
HHMMSSss+DDMMSSs
23- 37 A15 --- Name Object Name in the Gaia-ESO archive
38- 42 F5.2 [-] A(Mg1) [6.0/8.0]? MgI abundance, 12+log(N/H)
44- 48 F5.2 [-] e_A(Mg1) ? rms uncertainty of Mg1 abundance
50- 54 F5.2 [-] A(Al1) [5.2/7.0]? AlI abundance, 12+log(N/H)
56- 60 F5.2 [-] e_A(Al1) ? rms uncertainty of Al1 abundance
62- 66 F5.2 [-] A(Si1) [5.9/8.2]? SiI abundance, 12+log(N/H)
68- 72 F5.2 [-] e_A(Si1) ? rms uncertainty of Si1 abundance
74- 78 F5.2 [-] A(Ca1) [3.7/6.9]? CaI abundance, 12+log(N/H)
80- 84 F5.2 [-] e_A(Ca1) ? rms uncertainty of Ca1 abundance
86- 90 F5.2 [-] A(Ca2) [3.7/6.8]? CaII abundance, 12+log(N/H)
92- 96 F5.2 [-] e_A(Ca2) ? rms uncertainty of Ca2 abundance
98-102 F5.2 [-] A(Ti1) [3.2/5.4]? TiI abundance, 12+log(N/H)
104-108 F5.2 [-] e_A(Ti1) ? rms uncertainty of Ti1 abundance
110-114 F5.2 [-] A(Ti2) [3.4/5.6]? TiII abundance, 12+log(N/H)
116-120 F5.2 [-] e_A(Ti2) ? rms uncertainty of Ti2 abundance
122-126 F5.2 [-] A(Cr1) [2.8/6.1]? CrI abundance, 12+log(N/H)
128-132 F5.2 [-] e_A(Cr1) ? rms uncertainty of Cr1 abundance
134-138 F5.2 [-] A(Ni1) [4.5/6.9]? NiI abundance, 12+log(N/H)
140-144 F5.2 [-] e_A(Ni1) ? rms uncertainty of Ni1 abundance
146-150 F5.2 [-] A(Y2) [-0.2/3]? YII abundance, 12+log(N/H)
152-156 F5.2 [-] e_A(Y2) ? rms uncertainty of Y2 abundance
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Acknowledgements:
Sarunas Mikolaitis, Sarunas.Mikolaitis(at)oca.eu
(End) Sarunas Mikolaitis [OCA, Nice, France], Patricia Vannier [CDS] 10-Sep-2014