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J/ApJ/847/142 Ultra-metal-poor stars LTE and NLTE abundances (Ezzeddine+, 2017)

Ultra-metal-poor stars: spectroscopic determination of stellar atmospheric parameters using iron non-LTE line abundances. Ezzeddine R., Frebel A., Plez B. <Astrophys. J., 847, 142 (2017)> =2017ApJ...847..142E
ADC_Keywords: Abundances, [Fe/H]; Stars, metal-deficient; Equivalent widths; Models Keywords: line: formation ; stars: abundances ; stars: atmospheres ; stars: fundamental parameters ; stars: Population II Abstract: We present new ultra-metal-poor stars parameters with [Fe/H] < -4.0 based on line-by-line non-local thermodynamic equilibrium (NLTE) abundances using an up-to-date iron model atom with a new recipe for non-elastic hydrogen collision rates. We study the departures from LTE in their atmospheric parameters and show that they can grow up to ∼1.00dex in [Fe/H], ∼150K in Teff and ∼0.5dex in logg toward the lowest metallicities. Accurate NLTE atmospheric stellar parameters, in particular [Fe/H] being significantly higher, are the first step to eventually providing full NLTE abundance patterns that can be compared with Population III supernova nucleosynthesis yields to derive properties of the first stars. Overall, this maximizes the potential of these likely second-generation stars to investigate the early universe and how the chemical elements were formed. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 62 631 Atomic linelists and obtained FeI and FeII abundances of the ultra-metal-poor stars table3.dat 99 20 *Our results for the average FeI, FeII, and total Fe abundances with their standard deviation errors
Note on table3.dat: Values are reported relative to the solar iron abundance of ε(Fe)=7.50 from Asplund+ (2009ARA&A..47..481A).
See also: J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992) J/A+A/275/101 : Chemical evolution of the galactic disk I. (Edvardsson+ 1993) J/A+A/416/1117 : Abundances in the early Galaxy (Cayrel+, 2004) J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013) J/ApJ/762/25 : The most metal-poor stars in HES and SDSS. I. (Norris+, 2013) J/A+A/572/A103 : Inelastic silicon-hydrogen collision data (Belyaev+, 2014) J/A+A/564/A133 : Gaia FGK benchmark stars: metallicity (Jofre+, 2014) J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014) J/A+A/579/A28 : Abundances of 3 CEMP stars (Bonifacio+, 2015) J/ApJS/216/1 : New FeI level energies from stellar spectra (Peterson+, 2015) J/A+A/587/A114 : Inelastic calcium-hydrogen collision data (Belyaev+, 2016) J/A+A/586/A120 : Grid of 1D models for Mg line formation (Osorio+, 2016) J/A+A/593/A27 : Inelastic beryllium-hydrogen collision data (Yakovleva+, 2016) J/ApJ/833/225 : -2.6≤[Fe/H]≤0.2 F and G dwarfs. II. Abundances (Zhao+, 2016) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 15 A15 --- Name Star name 17- 20 A4 --- Ion Species identifier 22- 29 F8.3 0.1nm lambda [3255.8/5586.8] Wavelength λ; in Angstroms unit 31- 35 F5.3 eV ExPot [0/4.4] Excitation potential 37- 41 F5.2 [-] log(gf) [-4.8/0.7] Log of the oscillator strength 44 A1 --- l_EW Limit flag on EW 45- 49 F5.1 10-13m EW [0.8/143] Equivalent width of line, in milli-Angstroms unit 51 A1 --- l_logeLTE Limit flag on loge-LTE 52- 55 F4.2 [-] logeLTE [0.2/4.1] logε abundance of line, LTE 57 A1 --- l_logeNLTE Limit flag on loge-NLTE 58- 62 F5.3 [-] logeNLTE [0.9/4.7] logε abundance of line, NLTE
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1 I1 --- Group [1/3] Ultra-metal-poor star group (1) 3- 17 A15 --- Name Star name 19 A1 --- f_Name [bc] Flag on Name (2) 21 A1 --- l_[FeI/H] Limit flag on [FeI/H] 22- 26 F5.2 [Sun] [FeI/H] LTE FeI abundance 28- 31 F4.2 [Sun] e_[FeI/H] [0.07/0.3]? Uncertainty on [FeI/H] 33 A1 --- l_[FeII/H] Limit flag on [FeI/H] 34- 38 F5.2 [Sun] [FeII/H] ? LTE FeII abundance 40- 43 F4.2 [Sun] e_[FeII/H] [0.08/0.2]? Uncertainty on [FeII/H] 45 A1 --- l_[FeI/H]n Limit flag on [FeI/H] 46- 50 F5.2 [Sun] [FeI/H]n non-LTE FeI abundance 52- 55 F4.2 [Sun] e_[FeI/H]n [0.03/0.2]? Uncertainty on [FeI/H]n 57 A1 --- l_[FeII/H]n Limit flag on [FeI/H] 58- 62 F5.2 [Sun] [FeII/H]n ? non-LTE FeII abundance 64- 67 F4.2 [Sun] e_[FeII/H]n [0.07/0.2]? Uncertainty on [FeII/H]n 69 A1 --- l_[Fe/H] Limit flag on [FeI/H] 70- 74 F5.2 [Sun] [Fe/H] LTE total Fe abundance 76- 79 F4.2 [Sun] e_[Fe/H] [0.07/0.3]? Uncertainty on [Fe/H] 81 A1 --- l_[Fe/H]n Limit flag on [FeI/H] 82- 86 F5.2 [Sun] [Fe/H]n non-LTE total Fe abundance 88- 91 F4.2 [Sun] e_[Fe/H]n [0.03/0.2]? Uncertainty on [Fe/H]n 93- 95 I3 --- NFeI Number of FeI lines used 96 A1 --- n_NFeI a: No line detection, upper limit only 98 I1 --- NFeII Number of FeII lines used 99 A1 --- n_NFeII a: No line detection, upper limit only
Note (1): Group as follows: 1 = -4.5 < [Fe/H] < -4.0 2 = -5.0 < [Fe/H] < -4.5 3 = [Fe/H] < -5.0 Note (2): b = uncertainties of 1σ c = uncertainties of 3σ
History: From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Jun-2018
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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