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J/ApJ/837/176 Spectroscopic obs. of 2 red giant stars in omega Cen (Yong+, 2017)

A chemical signature from fast-rotating low-metallicity massive stars: ROA 276 in ω Centauri. Yong D., Norris J.E., Da Costa G.S., Stanford L.M., Karakas A.I., Shingles L.J., Hirschi R., Pignatari M. <Astrophys. J., 837, 176-176 (2017)> =2017ApJ...837..176Y (SIMBAD/NED BibCode)
ADC_Keywords: Stars, giant ; Abundances, [Fe/H] ; Equivalent widths ; Clusters, globular Keywords: globular clusters: individual: omega Centauri; stars: abundances; stars: Population II Abstract: We present a chemical abundance analysis of a metal-poor star, ROA276, in the stellar system ω Centauri. We confirm that this star has an unusually high [Sr/Ba] abundance ratio. Additionally, ROA 276 exhibits remarkably high abundance ratios, [X/Fe], for all elements from Cu to Mo along with normal abundance ratios for the elements from Ba to Pb. The chemical abundance pattern of ROA 276, relative to a primordial ω Cen star ROA 46, is best fit by a fast-rotating low-metallicity massive stellar model of 20M, [Fe/H]=-1.8, and an initial rotation 0.4 times the critical value; no other nucleosynthetic source can match the neutron-capture element distribution. ROA 276 arguably offers the most definitive proof to date that fast-rotating massive stars contributed to the production of heavy elements in the early universe. Description: We obtained a high-resolution optical spectrum for the red giant ROA276 and a comparison red giant star ROA46 (V=11.54) using the Magellan Inamori Kyocera Echelle spectrograph at the 6.5m Magellan Clay Telescope on 2007 June 22-23. Both stars have proper motions and radial velocities consistent with cluster membership. The total exposure time was 10 minutes per target (spectral resolution of R=56000 and R=44000 in the blue and red arms, respectively). Objects: ---------------------------------------------------------- RA (ICRS) DE Designation(s) ---------------------------------------------------------- 13 26 47.28 -47 28 46.1 ω Centauri = * ome Cen ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 37 2 Stellar parameters for the program stars table2.dat 56 333 Line list, equivalent widths, and abundances
See also: VII/195 : Globular Clusters in the Milky Way (Harris, 1996) VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006) J/A+A/404/187 : Equivalent widths for metal-poor stars (Gratton+, 2003) J/ApJ/645/613 : Abundances of HD 221170 (Ivans+, 2006) J/ApJS/162/227 : Transition probabilities for SmII (Lawler+, 2006) J/A+A/493/959 : UBV(RI)cHalpha photometry in omega Cen (Bellini+, 2009) J/ApJS/182/51 : Transition proba. of rare earth elements (Lawler+, 2009) J/MNRAS/403/1413 : Updated stellar yields from AGB models (Karakas, 2010) J/ApJ/742/37 : Abundances of six RGB stars in M22 (Roederer+, 2011) J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011) J/ApJ/750/76 : R-process peaks elements in HD 160617 (Roederer+, 2012) J/ApJ/797/44 : Evolution and nucleosynthesis of AGB stars (Fishlock+, 2014) J/A+A/571/A47 : Extensive linelist of CH in stellar atm. (Masseron+, 2014) J/A+A/574/A129 : The First CEMP star in the Sculptor dSph (Skuladottir+, 2015) J/ApJS/225/24 : NuGrid stellar data set I. Yields (Pignatari+, 2016) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 A3 --- --- [ROA] 5- 7 I3 --- ID Red giant star identifier 9- 12 I4 K Teff [4075/4125] Spectroscopic effective temperature (1) 14- 16 F3.1 [cm/s2] logg [0.2/0.7] Spectroscopic surface gravity (1) 18- 21 F4.2 km/s xi [1.7/2.4] Microturbulent velocity (1) 23- 27 F5.2 [Sun] [Fe/H] [-1.8/-1.3] Spectroscopic [Fe/H] abundance 29- 32 I4 K Teffp [4024/4130] Photometric effective temperature 34- 37 F4.2 [cm/s2] loggp [0.3/0.8] Photometric log of surface gravity
Note (1): The effective temperature, surface gravity, and microturbulent velocity (ξt), were obtained by enforcing excitation and ionization balance for Fe lines. The uncertainties in Teff, logg, and ξt are 50K, 0.2dex, and 0.2km/s, respectively.
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 5 A5 --- Ion Species identifier 7- 13 F7.2 0.1nm lambda [4057.8/7947.6]? Wavelength in Angstroms (1) 15- 18 F4.2 eV LEP [0/5.2]? Lower excitation potential 20- 25 F6.2 [-] log(gf) [-10.3/0.7]? Log oscillator strength 27- 31 F5.1 10-13m EW276 [20/150]? Equivalent width for ROA 276 (2) 33 A1 --- f_EW276 [s] s = spectrum synthesis 35- 39 F5.1 10-13m EW46 [19.8/150]? Equivalent width for ROA 46 (2) 41 A1 --- f_EW46 [s] s = spectrum synthesis 43- 47 F5.2 [-] loge276 [-1/8.1]? Log abundance for ROA 276 49- 53 F5.2 [-] loge46 [-1.3/7.6]? Log abundance for ROA 46 55- 56 I2 --- Ref [1/21] Source code (3)
Note (1): The wavelength range for CH is 4270-4330Å. Note (2): In units of milli-Angstroms Note (3): Code as follows: 1 = Masseron et al. (2014, J/A+A/571/A47); 2 = Gratton et al. (2003, J/A+A/404/187) and references therein; 3 = values as used in Yong et al. (2005A&A...438..875Y) where the references include Kurucz & Bell (1995, Atomic line list (Cambridge: Smithsonian Astrophysical Observatory)), Prochaska et al. (2000AJ....120.2513P), Den Hartog et al. (2003ApJS..148..543D), Ivans et al. (2001AJ....122.1438I), and Ramirez & Cohen (2002AJ....123.3277R); 4 = Oxford group including Blackwell et al. (1979MNRAS.186..633B), Blackwell et al. (1979MNRAS.186..657B), Blackwell et al. (1980MNRAS.191..445B), Blackwell et al. (1986MNRAS.220..549B), Blackwell et al. (1995A&A...296..217B); 5 = Kock & Richter (1968ZA.....69..180K); 6 = Hannaford & Lowe (1983OptEn..22..532H); 7 = Roederer & Lawler (2012, J/ApJ/750/76); 8 = mean of lifetimes from Simsarian et al. (1998PhRvA..57.2448S) and Volz & Schmoranzer (1996PhST...65...48V) weighted according to uncertainties, via Morton (2000ApJS..130..403M); 9 = Wiese F. (2009, CRC Handbook of Chemistry and Physics 90th ed. (Boca Raton, FL: CRC Press) 10) 10 = Biemont et al. (2011MNRAS.414.3350B); 11 = Biemont et al. (1981ApJ...248..867B); 12 = Ljung et al. (2006A&A...456.1181L); 13 = Whaling & Brault (1988PhyS...38..707W); 14 = Davidson et al. (1992A&A...255..457D) using hfs/IS from McWilliam (1998AJ....115.1640M); 15 = Lawler et al. (2001ApJ...556..452L), using hfs from Ivans et al. (2006, J/ApJ/645/613); 16 = Lawler et al. (2009, J/ApJS/182/51); 17 = Li et al. (2007PhyS...76..577L); 18 = Den Hartog et al. (2003ApJS..148..543D), using hfs/IS from Roederer et al. (2008ApJ...675..723R) when available; 19 = Lawler et al. (2006, J/ApJS/162/227), using hfs/IS from Roederer et al. (2008ApJ...675..723R) when available; 20 = Lawler et al. (2001ApJ...563.1075L), using hfs/IS from Ivans et al. (2006, J/ApJ/645/613); 21 = Biemont et al. (2000MNRAS.312..116B), using hfs/IS from Roederer et al. (2012ApJS..203...27R).
History: From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 25-Oct-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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