J/A+A/530/A15 Abundances of 94 stars (Nissen+, 2011)
Two distinct halo populations in the solar neighborhood.
II. Evidence from stellar abundances of Mn, Cu, Zn, Y, and Ba.
Nissen P.E., Schuster W.J.
<Astron. Astrophys. 530, A15 (2011)>
=2011A&A...530A..15N 2011A&A...530A..15N
ADC_Keywords: Stars, nearby ; Abundances ; Equivalent widths
Keywords: stars: atmospheres - stars: abundances - Galaxy: abundances -
Galaxy: halo - Galaxy: formation
Abstract:
Abundances of Mn, Cu, Zn, Y, and Ba are determined for a sample of
stars previously studied by Nissen & Schuster (2010, Cat.
J/A+A/511/L10). Equivalent widths of atomic lines are measured from
high resolution VLT/UVES and NOT/FIES spectra and used to derive
abundance ratios from an LTE analysis based on MARCS model
atmospheres. The analysis is made relative to two thick-disk stars,
HD22879 and HD76932, such that very precise differential values are
obtained.
Description:
Atmospheric parameters and abundance ratios, [Mn/Fe], [Cu/Fe],
[Zn/Fe], [Y/Fe], and [Ba/Fe], are given for 78 halo stars and 16
thick-disk stars observed with the ESO VLT/UVES and NOT/FIES
spectrographs at high resolution.
Six stars, G20-15, HD148816, HD179626, HD189558, HD193901 and
HD194598 have been observed with the two spectrographs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 75 53 Data based on VLT/UVES spectra
table2.dat 75 47 Data based on NOT/FIES spectra
table3u.dat 46 10388 Equivalent widths from VLT/UVES spectra
table3f.dat 46 9212 Equivalent widths from NOT/FIES spectra
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See also:
J/A+A/511/L10 : Abundances and space velocities of 94 stars (Nissen+, 2010)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object name
11 A1 --- m_Name Multiplicity index on Name
13- 16 I4 K Teff Effective temperature
18- 21 F4.2 [cm/s2] logg Logarithmic surface gravity
23- 27 F5.2 [Sun] [Fe/H] Iron-to-hydrogen ratio
29- 32 F4.2 [Sun] [a/Fe] α-to-iron ratio (1)
34- 38 F5.2 [Sun] [Mn/Fe] Manganese-to-iron ratio
40- 44 F5.2 [Sun] [Cu/Fe] ? Copper-to-iron ratio
46- 50 F5.2 [Sun] [Zn/Fe] Zinc-to-iron ratio
52- 56 F5.2 [Sun] [Y/Fe] Yttrium-to-iron ratio
58- 62 F5.2 [Sun] [Ba/Fe] Barium-to-iron ratio
64- 75 A12 --- Class Population (2)
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Note (1): [α/Fe] is defined as 1/4([Mg/Fe]+[Si/Fe]+[Ca/Fe]+[Ti/Fe]).
Note (2): Classification of star as belonging to the thick-disk (TD), the
low-α halo, or the high-α halo population. For stars with
[Fe/H]←1.4, the classification is uncertain and given in parentheses.
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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- 10 A10 --- Name Object name
11 A1 --- m_Name Multiplicity index on Name
14- 17 A4 --- Ion Chemical element and ionization stage
20- 26 F7.2 0.1nm lambda Wavelength of line (Å)
30- 33 F4.2 eV chi.ex Excitation energy of lower level
36- 40 F5.2 --- loggf Logarithmic oscillator strength (1)
42- 46 F5.1 0.1pm EW ? Equivalent width (mÅ)
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Note (1): log(gf) is determined from an "inverted" abundance analysis of
the two standard stars, HD22879 and HD76932.
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Acknowledgements:
Poul Erik Nissen, pen(at)phys.au.dk
(End) Poul Erik Nissen [Aarhus University], Patricia Vannier [CDS] 14-Apr-2011