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J/ApJ/698/2048    Abundances of red giants in ω Cen       (Johnson+, 2009)

A large sample study of red giants in the globular cluster omega Centauri (NGC 5139). Johnson C.I., Pilachowski C.A., Rich R.M., Fulbright J.P. <Astrophys. J., 698, 2048-2065 (2009)> =2009ApJ...698.2048J
ADC_Keywords: Stars, giant ; Equivalent widths ; Abundances, [Fe/H] ; Clusters, globular ; Photometry, infrared Keywords: globular clusters: general - globular clusters: individual (omega Centauri, NGC 5139) - stars: abundances - stars: Population II Abstract: We present abundances of several light, α, Fe-peak, and neutron-capture elements for 66 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri (ω Cen). Our observations lie in the range 12.0<V<13.5 and focus on the intermediate and metal-rich RGBs. Abundances were determined using equivalent width measurements and spectrum synthesis analyses of moderate resolution (R∼18000) spectra obtained with the Blanco 4m telescope and Hydra multifiber spectrograph. Combining these data with previous work, we find that there are at least four peaks in the metallicity distribution function at [Fe/H]=-1.75, -1.45, -1.05, and -0.75, which correspond to about 55%, 30%, 10%, and 5% of our sample, respectively. We conclude that the metal-rich population must be at least 1-2Gyr younger than the metal-poor stars, owing to the long timescales needed for strong s-process enrichment and the development of a large contingent of mass transfer binaries. Description: All observations were taken at the Cerro Tololo Inter-American Observatory on 2006 May 26 and 2006 May 27 using the Blanco 4m telescope and Hydra multifiber spectrograph. Target stars, coordinates, photometry, and membership probabilities were taken from the proper motion study by van Leeuwen et al. (2000, Cat. J/A+A/360/472). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 84 66 Photometry, membership, and atmospheric parameters ew.dat 36 5676 Equivalent Widths table3.dat 95 65 Derived abundances
See also: II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) J/ApJS/99/637 : Equivalent widths for 54 red giants (Norris+ 1995) J/ApJ/462/241 : Ca abundance for Omega Cen red giants (Norris+ 1996) J/A+A/360/472 : Proper motions in omega Centauri (van Leeuwen+, 2000) J/MNRAS/357/265 : BVI photometry of omega Cen red giants (Sollima+, 2005) J/ApJ/681/1505 : Abundances of red giants in ω Cen (Johnson+, 2008) J/MNRAS/396/2183 : Radial velocities of red giants in ω Cen (Sollima+ 2009) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 5 I5 --- LEID van Leeuwen et al. identification number (G1) 7- 10 I4 --- ROA ? Woolley (1966ROAn....2....1W) identification number 12- 17 F6.3 mag Vmag The V band magnitude 19- 23 F5.3 mag B-V The (B-V) color index 25- 30 F6.3 mag Jmag 2MASS Johnson J band magnitude 32- 37 F6.3 mag Hmag 2MASS Johnson H band magnitude 39- 44 F6.3 mag Ksmag 2MASS Johnson Ks band magnitude 46- 51 F6.3 mag VMAG Absolute V band magnitude 53- 55 I3 % Prob van Leeuwen et al. 2000, Cat. J/A+A/360/472 membership probability 57- 60 I4 K Teff Effective temperature 62- 65 F4.2 [cm/s2] log(g) Log surface gravity 67- 71 F5.2 [Sun] [Fe/H] Average metallicity 73- 76 F4.2 km/s Vt Turbulent velocity ξ 78- 80 I3 --- SN6125 ? Signal-to-Noise at 612.5nm 82- 84 I3 --- SN6670 ? Signal-to-Noise at 667.0nm
Byte-by-byte Description of file: ew.dat
Bytes Format Units Label Explanations
1- 5 I5 --- LEID van Leeuwen et al. identification number (G1) 7- 13 F7.2 0.1nm lambda Wavelength in Angstroms 15- 19 A5 --- Ion Ion identification 21- 24 F4.2 eV ExPot Excitation potential 26- 30 F5.2 [---] log(gf) Log of the oscillator strength 32- 34 I3 0.1pm EW ? Equivalent width, in mÅ = 10-13m (1) 36 A1 --- f_EW [s] Flag indicating synthetic value
Note (1): Equivalent widths were measured by interactively fitting multiple Gaussians to isolated and blended line profiles. Suitable lines were identified using the solar and Arcturus atlases (at Our adopted log(gf) values were determined by measuring equivalent widths in the solar atlas and then modified until all lines yielded abundances consistent with the photospheric values given in Anders & Grevesse (1989GeCoA..53..197A).
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 5 I5 --- LEID van Leeuwen et al. identification number (G1) 7- 11 F5.2 [Sun] [Fe1/H] Derived [FeI/H] abundance 13- 17 F5.2 [Sun] [Fe2/H] ? Derived [FeII/H] abundance 19- 23 F5.2 [Sun] [Fe/H] Average derived [Fe/H] abundance 25- 29 F5.2 [Sun] [Na1/Fe] ? Derived [NaI/Fe] abundance 31- 35 F5.2 [Sun] [Al1/Fe] ? Derived [AlI/Fe] abundance 37- 41 F5.2 [Sun] [Ca1/Fe] ? Derived [CaI/Fe] abundance 43- 47 F5.2 [Sun] [Sc1/Fe] ? Derived [ScI/Fe] abundance 49- 53 F5.2 [Sun] [Sc2/Fe] ? Derived [ScII/Fe] abundance 55- 59 F5.2 [Sun] [Sc/Fe] ? Average derived [Sc/Fe] abundance 61- 65 F5.2 [Sun] [Ti1/Fe] ? Derived [TiI/Fe] abundance 67- 71 F5.2 [Sun] [Ti2/Fe] ? Derived [TiII/Fe] abundance 73- 77 F5.2 [Sun] [Ti/Fe] ? Average derived [Ti/Fe] abundance 79- 83 F5.2 [Sun] [Ni1/Fe] ? Derived [NiI/Fe] abundance 85- 89 F5.2 [Sun] [La2/Fe] ? Derived [LaII/Fe] abundance 91- 95 F5.2 [Sun] [Eu2/Fe] ? Derived [EuII/Fe] abundance
Global notes: Note (G1): van Leeuwen et al. 2000, Cat. J/A+A/360/472 identification number; <Cl* NGC 5139 Leid NNNNN> in Simbad.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 22-Jun-2011
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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