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J/ApJ/681/1524      Detailed abundances for 28 metal-poor stars     (Lai+, 2008)

Detailed abundances for 28 metal-poor stars: stellar relics in the Milky Way. Lai D.K., Bolte M., Johnson J.A., Lucatello S., Heger A., Woosley S.E. <Astrophys. J., 681, 1524-1556 (2008)> =2008ApJ...681.1524L
ADC_Keywords: Equivalent widths ; Abundances, [Fe/H] ; Effective temperatures ; Stars, metal-deficient Keywords: nuclear reactions, nucleosynthesis, abundances - stars: abundances - stars: Population II - supernovae: general Abstract: We present the results of an abundance analysis for a sample of stars with -4<[Fe/H]←2. The data were obtained with the HIRES spectrograph at Keck Observatory. The set includes 28 stars, with effective temperature ranging from 4800 to 6600K. For 13 stars with [Fe/H]←2.6, including nine with [Fe/H]←3.0 and one with [Fe/H]=-4.0, these are the first reported detailed abundances. For the most metal-poor star in our sample, CS 30336-049, we measure an abundance pattern that is very similar to stars in the range [Fe/H]~-3.5, including a normal C+N, abundance. We also find that it has very low but measurable Sr and Ba, indicating some neutron-capture activity even at this low of a metallicity. We explore this issue further by examining other very neutron capture-deficient stars and find that, at the lowest levels, [Ba/Sr] exhibits the ratio of the main r-process. We also report on a new r-process-enhanced star, CS 31078-018. This star has [Fe/H]=-2.85, [Eu/Fe]=1.23, and [Ba/Eu]=-0.51. CS 31078-018 exhibits an "actinide boost," i.e., much higher [Th/Eu] than expected and at a similar level to CS 31082-001. Our spectra allow us to further constrain the abundance scatter at low metallicities, which we then use to fit to the zero-metallicity Type II supernova yields of Heger & Woosley (2008arXiv0803.3161H). We find that supernovae with progenitor masses between 10 and 20M provide the best matches to our abundances. Description: The data were obtained from multiple runs at the HIRES spectrograph at Keck Observatory between 2001 and 2006. We chose our sample from Lai et al. (2004, Cat. J/AJ/128/2402) and metal-poor candidates identified in the photometric sample of Schuster et al. (2004, Cat. J/A+A/422/527). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table5.dat 79 28 Stellar parameters width.dat 44 12659 Equivalent widths and atomic parameters for the 28 stars (tables 2, 3 and 4 of the paper)
See also: III/211 : Keck/HIRES Sky Line Atlas (Osterbrock+ 1997) J/A+A/305/245 : Fe I in metal-poor stars (Magain+, 1996) J/A+A/356/238 : Atmospheric parameters in metal-poor stars. III. (Carretta+, 2000) J/A+A/404/187 : Equivalent widths for metal-poor stars (Gratton+, 2003) J/AJ/128/2402 : Extremely metal-poor star candidates abundances (Lai+, 2004) J/A+A/422/527 : Metal-poor star uvby-beta photometry. X. (Schuster+, 2004) J/A+A/440/321 : Chemical abundances in 43 metal-poor stars (Jonsell+, 2005) J/A+A/522/A26 : Fe Abundances in metal-poor stars (Sbordone+ 2010) Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 11 A11 --- Name Star identification 13- 17 F5.2 [Sun] [Fe/H] Metallicity 19- 22 I4 K Teff Effective temperature (1) 24- 27 F4.2 [cm/s2] logg Surface gravity 29- 31 F3.1 km/s vt Microturbulence velocity 33- 37 F5.2 [eV] Chi Slope of the trend for all lines (2) 39- 43 F5.2 --- r Corresponding correlation coefficient for all lines 45- 47 I3 --- N Number of FeI lines used for all lines 49- 53 F5.2 [eV] Chi02 Slope of the trend for χ>0.2eV 55- 59 F5.2 --- r02 Corresponding correlation coefficient for χ>0.2eV 61- 63 I3 --- N02 Number of FeI lines used for χ>0.2eV 65- 69 F5.2 [eV] Chi12 Slope of the trend for χ>1.2eV 71- 75 F5.2 --- r12 Corresponding correlation coefficient for χ>1.2eV 77- 79 I3 --- N12 Number of FeI lines used for χ>1.2eV
Note (1): Effective temperatures are obtained using the V-K color of each star. Note (2): Slope per dex(eV); see section 3.3.1 for more details.
Byte-by-byte Description of file: width.dat
Bytes Format Units Label Explanations
1- 11 A11 --- Name Star designation 13- 19 F7.2 0.1nm Wave Wavelength in Angstroms 21 A1 --- f_Wave [*] Flag on Wave (1) 23- 26 F4.1 --- Element Element identification 28- 32 F5.2 [-] log(gf) Log of the oscillator strength 34- 37 F4.2 eV ExPot Excitation potential 39- 44 F6.2 10-13m EW ? Equivalent width (mÅ)
Note (1): * = abundance was derived through spectral synthesis. Except for the Al lines, all of these lines take into account hyperfine splitting (HFS).
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 03-Nov-2010
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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