J/ApJ/724/975 Heavy elements abundances of metal-poor stars (Roederer+, 2010)
The ubiquity of the rapid neutron-capture process.
Roederer I.U., Cowan J.J., Karakas A.I., Kratz K.-L., Lugaro M.,
Simmerer J., Farouqi K., Sneden C.
<Astrophys. J., 724, 975-993 (2010)>
=2010ApJ...724..975R 2010ApJ...724..975R
ADC_Keywords: Abundances ; Equivalent widths ; Stars, metal-deficient ;
Stars, giant; Spectra, optical
Keywords: nuclear reactions, nucleosynthesis, abundances - stars: abundances -
stars: Population II
Abstract:
To better characterize the abundance patterns produced by the
r-process, we have derived new abundances or upper limits for the
heavy elements zinc (Zn, Z=30), yttrium (Y, Z=39), lanthanum (La,
Z=57), europium (Eu, Z=63), and lead (Pb, Z=82). Our sample of 161
metal-poor stars includes new measurements from 88 high-resolution and
high signal-to-noise spectra obtained with the Tull Spectrograph on
the 2.7m Smith Telescope at the McDonald Observatory, and other
abundances are adopted from the literature. We use models of the
s-process in asymptotic giant branch stars to characterize the high
Pb/Eu ratios produced in the s-process at low metallicity, and our new
observations then allow us to identify a sample of stars with no
detectable s-process material.
Description:
Simmerer et al. (2004, Cat. J/ApJ/617/1091) obtained high-resolution
(R∼60000) and high signal-to-noise ratio (S/N∼100 at 4100Å) spectra
for 88 bright (V≤11.0) metal-poor dwarf and giant stars from the halo
and disk using the Tull Cross-dispersed Echelle Spectrograph on the
2.7m Smith Telescope at the McDonald Observatory. We adopt the
atmospheric parameters from Simmerer et al. (2004, Cat. J/ApJ/617/1091)
and derive new zinc (Zn, Z=30), Y, and Pb abundances for the stars in
this sample.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 36 83 Zinc and yttrium equivalent widths
table2.dat 66 161 Stellar abundances
refs.dat 70 36 References
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See also:
J/ApJ/711/573 : Detailed abundances in a halo stellar stream (Roederer+, 2010)
J/A+A/516/A46 : HE 2327-5642 abundance analysis (Mashonkina+, 2010)
J/ApJS/182/80 : Rare earth abundances (Sneden+, 2009)
J/ApJ/689/1031 : Heavy element abundances in giant stars (Yong+, 2008)
J/ApJ/681/1524 : Detailed abundances for 28 metal-poor stars (Lai+, 2008)
J/ApJ/645/613 : Abundances of HD 221170 (Ivans+, 2006)
J/A+A/439/129 : HERES II. Spectroscopic analysis (Barklem+, 2005)
J/ApJ/617/1091 : La and Eu abundances in 85 stars (Simmerer+, 2004)
J/A+A/416/1117 : Abundances in the early Galaxy (Cayrel+, 2004)
J/A+A/403/1105 : Extremely metal-poor giants EWs (Francois+, 2003)
J/AJ/120/1841 : Abundances and Kinematics of Halo and Disk Stars (Fulbright
2000)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Star Star identification
12- 15 F4.1 0.1pm ZnI47 ZnI 4722.16Å equivalent width in mÅ
17- 20 F4.1 0.1pm ZnI48 ? ZnI 4810.54Å equivalent width in mÅ
22- 26 F5.1 0.1pm YII48 ? YII 4833.68Å equivalent width in mÅ
28- 31 F4.1 0.1pm YII50 ? YII 5087.42Å equivalent width in mÅ
33- 36 F4.1 0.1pm YII52 ? YII 5200.41Å equivalent width in mÅ
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Star Star identification
17- 21 F5.2 [Sun] [Fe/H] Abundance of [Fe/H]
23- 24 I2 --- r_[Fe/H] Reference for [Fe/H] (see refs.dat file)
26- 30 F5.2 [-] log(ZnI) ? Log of ZnI abundance (log(N/H)+12)
32- 36 F5.2 [-] log(YII) ? Log of YII abundance (log(N/H)+12)
38- 42 F5.2 [-] log(LaII) ? Log of LaII abundance (log(N/H)+12)
44- 48 F5.2 [-] log(EuII) ? Log of EuII abundance (log(N/H)+12)
50 A1 --- l_log(PbI) Limit flag on loge(PbI)
51- 55 F5.2 [-] log(PbI) ? Log of PbI abundance (log(N/H)+12)
57- 64 A8 --- Ref Reference(s) (see refs.dat file)
66 I1 --- Class [0/3] Classification code (1)
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Note (1): Classification as follows:
1 = logε(Pb/Eu)<+1.8
2 = member of the stellar stream analyzed by Roederer et al. (2010,
Cat. J/ApJ/711/573)
3 = logε(Pb/Eu)<+0.9, as well as HD 88609 and HD 122563
0 = none of 1-3 or [Fe/H]≥-1.4.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Code reference
4- 22 A19 --- BibCode Bibcode
24- 42 A19 --- Aut First author's name
44- 70 A27 --- Comm Comment
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 02-Aug-2012