J/ApJ/645/613 Abundances of HD 221170 (Ivans+, 2006)
Near-ultraviolet observations of HD 221170:
new insights into the nature of r-process-rich stars.
Ivans I.I., Simmerer J., Sneden C., Lawler J.E., Cowan J.J., Gallino R.,
Bisterzo S.
<Astrophys. J., 645, 613-633 (2006)>
=2006ApJ...645..613I 2006ApJ...645..613I
ADC_Keywords: Stars, variable ; Abundances
Keywords: Galaxy: abundances - Galaxy: evolution -
nuclear reactions, nucleosynthesis, abundances - stars: abundances -
stars: individual (HD 221170) - stars: Population II
Abstract:
Employing high-resolution spectra obtained with the near-UV-sensitive
detector on the Keck I HIRES, supplemented by data obtained with the
McDonald Observatory 2d-coude, we have performed a comprehensive
chemical composition analysis of the bright r-process-rich metal-poor
red giant star HD 221170. Analysis of 57 individual neutral and
ionized species yielded abundances for a total of 46 elements and
significant upper limits for an additional five. Model stellar
atmosphere parameters were derived with the aid of ∼200 Fe peak
transitions. From more than 350 transitions of 35 neutron-capture
(Z>30) species, abundances for 30 neutron-capture elements and upper
limits for three others were derived. Utilizing 36 transitions of La,
16 of Eu, and seven of Th, we derive ratios of logε(Th/La)=-0.73
(σ=0.06) and logε(Th/Eu)=-0.60 (σ=0.05), values in
excellent agreement with those previously derived for other
r-process-rich metal-poor stars such as CS 22892-052, BD +17 3248, and
HD 115444. Based on the Th/Eu chronometer, the inferred age is
11.7±2.8Gyr. The abundance distribution of the heavier
neutron-capture elements (Z≥56) is fitted well by the predicted
scaled solar system r-process abundances, as also seen in other
r-process-rich stars. Unlike other r-process-rich stars, however,
we find that the abundances of the lighter neutron-capture elements
(37<Z<56) in HD 221170 are also in agreement with the abundances
predicted for the scaled solar r-process pattern.
Objects:
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RA (2000) DE Designation(s)
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23 29 28.8 +30 25 58 HD 221170 = HIP 115949
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 72 647 Abundances derived from individual features
table2.dat 27 193 ScII(Z=21) and MnI(Z=25) linelists
table4.dat 54 984 Isotopic hyperfine structure patterns: 139La(Z=57)
table6.dat 54 732 Isotopic hyperfine structure patterns:
151Eu and 153Eu (Z=63) Solar System Mix
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See also:
J/A+A/430/255 : Abundances of HD221170 (Yushchenko+, 2005)
J/ApJ/617/1091 : La and Eu abundances (Simmerer+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- El Element
4- 7 F4.2 --- Abd Adopted Solar Abundance for El (H=12)
9- 10 I2 --- Z Atomic number of El
12- 13 A2 --- Ion Ionization State
15- 21 F7.2 0.1nm Wave ? Wavelength in Angstroms
23- 24 A2 --- f_Wave Flag on Wavelength (1)
26- 29 F4.2 eV ExtPot ? Excitation Potential
31- 37 F7.3 [-] log(gf) ? Log of the Oscillator Strength
39- 43 F5.1 10-13m EW ? Equivalent Width in mÅ
45- 47 A3 --- f_EW [syn ] EW derived from synthetic spectrum (2)
49 A1 --- l_log(e) Limit flag on log(e)
50- 55 F6.2 --- log(e) ? Log ε abundance (H=12)
57 A1 --- l_[X/Fe] Limit flag on [X/Fe]
58- 63 F6.2 [Sun] [X/Fe] ? [X/Fe] abundance (3)
65- 72 A8 --- Note Additional note (4)
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Note (1): Indicates whether the CH-band (CH) or CN-band (CN) was employed.
See Section 3.4. The derived 12C/13C ratio is 7±2.
Note (2): 'syn' denotes a feature for which our derived abundance
relies on a spectrum synthesis computation.
Note (3): The abundances derived for individual feature relative to the
scaled solar value: [Fe I/H], [Fe II/H], or [X/<Fe>] with
<[Fe/H]≥-2.18.
Note (4): Notes as follows:
HFS = Denotes a feature for which hyperfine structure splitting was
accounted for.
iso = Denotes a feature for which isotopic splitting was accounted for.
d = Excluded from analysis (non-negligible non-LTE correction required).
e = Hyperfine structure not considered for EW<30mÅ.
f = Excluded from analysis (HFS information unavailable for
non-negligible HFS correction).
limit = upper limit for log(e) and [X/Fe].
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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- 8 F8.3 0.1nm Wave Wavelength in Angstroms
10- 14 A5 --- Species Species Identification
16- 20 F5.3 eV ExtPot Excitation Potential
22- 27 F6.3 [-] log(gf) Log of the Oscillator Strength (1)
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Note (1): Hyperfine structure information adopted from Kurucz & Bell (1995,
Kurucz CD-ROM 23, Atomic Line Data (Cambridge: SAO)), with log(gf)'s
normalized to those adopted in this study (see Section 3).
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Byte-by-byte Description of file: table4.dat table6.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 cm-1 WaveNum Center-of-Gravity Wavenumber
11- 19 F9.4 0.1nm Wave Center-of-Gravity Wavelength in Angstroms
21- 23 F3.1 --- Fup Component upper F or total angular momentum
25- 27 F3.1 --- Flow Component lower F or total angular momentum
29- 36 F8.5 cm-1 CWaveNum Component offset wavenumber wrt
Center-of-gravity Wavenumber
38- 46 F9.6 0.1nm CWave Component offset Wavelength wrt
Center-of-gravity Wavelength in Angstroms
48- 54 F7.5 --- Str Component strength (1)
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Note (1): Normalized to sum to one.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 02-Oct-2007