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J/A+A/604/A129 Formation of MW halo and its dwarf satellites (Mashonkina+, 2017)

The formation of the Milky Way halo and its dwarf satellites, a NLTE-1D abundance analysis. I. Homogeneous set of atmospheric parameters. Mashonkina L., Jablonka P., Pakhomov Yu, Sitnova T, North P. <Astron. Astrophys. 604, A129 (2017)> =2017A&A...604A.129M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, giant ; Stars, metal-deficient ; Spectroscopy ; Abundances ; Models, atmosphere ; Galaxies, nearby Keywords: stars: abundances - stars: atmospheres - stars: fundamental parameters - galaxies: dwarf - Local Group Abstract: We present a homogeneous set of accurate atmospheric parameters for a complete sample of very and extremely metal-poor stars in the dwarf spheroidal galaxies (dSphs) Sculptor, Ursa Minor, Sextans, Fornax, Bootes I, Ursa Major II, and Leo IV. We also deliver a Milky Way (MW) comparison sample of giant stars covering the -4<[Fe/H]←1.7 metallicity range. We show that, in the [Fe/H]=>-3.7 regime, the non-local thermodynamic equilibrium (NLTE) calculations with non-spectroscopic effective temperature (Teff) and surface gravity (log g) based on the photometric methods and known distance provide consistent abundances of the FeI and FeII lines. This justifies the FeI/FeII ionisation equilibrium method to determine log g for the MW halo giants with unknown distance. The atmospheric parameters of the dSphs and MW stars were checked with independent methods. In the [Fe/H]>-3.5 regime, the TiI/TiII ionisation equilibrium is fulfilled in the NLTE calculations. In the logg-Teff plane, all the stars sit on the giant branch of the evolutionary tracks corresponding to [Fe/H]=-2 to -4, in line with their metallicities. For some of the most metal-poor stars of our sample, we hardly achieve consistent NLTE abundances from the two ionisation stages for both iron and titanium. We suggest that this is a consequence of the uncertainty in the Teff-colour relation at those metallicities. The results of these work provide the base for a detailed abundance analysis presented in a companion paper. Description: Tables A.1 and A.2 from the article are presented. The first table contains atomic parameters of FeI/II and TiI/II lines. The second atmospheric parameters and FeI/II, TiI/II nLTE abundances. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file tablea1.dat 31 197 Line data tablea2.dat 92 59 Iron and titanium NLTE abundances for the investigated sample
See also: J/AJ/144/168 : Spectroscopy of Scl 1019417 and UMi 20103 (Kirby+, 2012) J/ApJ/802/93 : Chemical abundance analysis of 5 stars in Sculptor (Simon+, 2015) J/Apj/719/931 : Chemical evolution of the UMi dSph (Cohen+, 2010) J/ApJ/763/61 : Abundances of 7 red giant members of BootesI (Gilmore+, 2013) J/ApJ/711/350 : Metal-poor giant Boo-1137 abundances (Norris+, 2010) J/ApJ/826/110 : Boo-127 and Boo-980 high-resolution spectra (Frebel+, 2016) J/ApJ/708/560 : Spectroscopy of UMa II and Coma Ber (Frebel+, 2010) J/ApJ/778/56 : Hamburg/ESO Survey extremely metal-poor stars (Cohen+, 2013) J/A+A/516/A46 : HE 2327-5642 abundance analysis (Mashonkina+, 2010) J/A+A/569/A43 : HE 2252-4225 abundance analysis (Mashonkina+, 2014) Byte-by-byte Description of file: tablea1.dat
Bytes Format Units Label Explanations
1- 2 A2 --- El Atom 4- 5 A2 --- Ion Ion 7- 13 F7.2 0.1nm lambda Wavelength 15- 18 F4.2 eV Eexc Excitation energy 20- 24 F5.2 --- loggf Adopted gf-value 26- 31 F6.3 rad/s/cm3 G6/NH van der Waals damping constant log(G6/NH) at 10000K
Byte-by-byte Description of file: tablea2.dat
Bytes Format Units Label Explanations
1- 12 A12 --- ID Star ID 14- 17 I4 K Teff Effective temperature 19- 22 F4.2 [cm/s2] logg Surface gravity 24- 28 F5.2 --- [Fe/H] Metallicity 30- 32 F3.1 km/s Vt Microturbulent velocity 36- 39 F4.2 --- epsFeI FeI NLTE abundance (log eps(H)=12) 41- 44 F4.2 --- e_FeI FeI NLTE abundance dispersion (sigma(log eps)) 46- 47 I2 --- o_FeI Number of FeI lines 51- 54 F4.2 --- epsFeII FeII NLTE abundance (log eps(H)=12) 56- 59 F4.2 --- e_FeII FeII NLTE abundance dispersion (sigma(log eps)) 61- 62 I2 --- o_FeII Number of FeII lines 66- 69 F4.2 --- epsTiI ? TiI NLTE abundance (log eps(H)=12) 71- 74 F4.2 --- e_TiI ? TiI NLTE abundance dispersion (sigma(log eps)) 76- 77 I2 --- o_TiI ? Number of TiI lines 81- 84 F4.2 --- epsTiII TiII NLTE abundance (log eps(H)=12) 86- 89 F4.2 --- e_TiII TiII NLTE abundance dispersion (sigma(log eps)) 91- 92 I2 --- o_TiII Number of TiII lines
Acknowledgements: Yury Pakhomov, pakhomov(at)inasan.ru
(End) Yury Pakhomov [INASAN, Russia], Patricia Vannier [CDS] 26-Apr-2017
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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