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J/ApJ/731/64       Spectroscopy of 300 RGBs in ω Cen      (Marino+, 2011)

Sodium-oxygen anticorrelation and neutron-capture elements in Omega Centauri stellar populations. Marino A.F., Milone A.P., Piotto G., Villanova S., Gratton R., D'Antona F., Anderson J., Bedin L.R., Bellini A., Cassisi S., Geisler D., Renzini A., Zoccali M. <Astrophys. J., 731, 64 (2011)> =2011ApJ...731...64M
ADC_Keywords: Abundances, [Fe/H] ; Stars, giant ; Clusters, globular Keywords: globular clusters: individual (NGC 5139) - stars: abundances - stars: Population II Abstract: Omega Centauri is no longer the only globular cluster known to contain multiple stellar populations, yet it remains the most puzzling. Due to the extreme way in which the multiple stellar population phenomenon manifests in this cluster, it has been suggested that it may be the remnant of a larger stellar system. In this work, we present a spectroscopic investigation of the stellar populations hosted in the globular cluster ω Centauri to shed light on its still puzzling chemical enrichment history. With this aim, we used FLAMES+GIRAFFE@VLT to observe 300 stars distributed along the multimodal red giant branch of this cluster, sampling with good statistics the stellar populations of different metallicities. We determined chemical abundances for Fe, Na, O, and n-capture elements Ba and La. We confirm that ω Centauri exhibits large star-to-star variations in iron with [Fe/H] ranging from ~-2.0 to ~-0.7dex. Barium and lanthanum abundances of metal-poor stars are correlated with iron, up to [Fe/H]~-1.5, while they are almost constant (or at least have only a moderate increase) in the more metal-rich populations. There is an extended Na-O anticorrelation for stars with [Fe/H]≲-1.3 while more metal-rich stars are almost all Na-rich. Sodium was found to mildly increase with iron over the entire metallicity range. Description: The data set consists of a large number of FLAMES/GIRAFFE spectra (proposals: 071.D-0217(A), 082.D-0424(A)) taken with the four setups HR09B, HR11, HR13, and HR15, which cover a spectral coverage of 5095-5404, 5597-5840, 6120-6405, and 6607-6965Å, respectively, with a resolution R∼20000-25000. The sample is composed of 300 red giants with V≤15. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 81 300 Coordinates RA and DEC, V magnitude, adopted atmospheric parameters and measured abundance ratios for the 300 stars in ω Cen
See also: J/MNRAS/416/L6 : AGB and RGB stars in ω Cen (McDonald+, 2011) J/ApJ/722/1373 : ω Centauri giants abundances (Johnson+, 2010) J/ApJ/698/2048 : Abundances of red giants in ω Cen (Johnson+, 2009) J/MNRAS/396/2183 : RVs of red giants in ω Cen (Sollima+ 2009) J/ApJ/681/1505 : Abundances of red giants in ω Cen (Johnson+, 2008) J/ApJ/661/L155 : Radial velocities RGB stars in omega Cen (Pancino+, 2007) J/ApJ/647/1075 : Age-metallicity relation of ω Cen (Stanford+, 2006) J/MNRAS/357/265 : BVI photometry of omega Cen red giants (Sollima+, 2005) J/A+A/360/472 : Proper motions in omega Centauri (van Leeuwen+, 2000) J/ApJ/462/241 : Ca abundance for Omega Cen red giants (Norris+ 1996) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 7 A7 --- ID Identification from the photometric catalog of Bellini et al. (2009A&A...507.1393B) (<NNNNNN> or RGB.NNN formats) 9- 18 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000) 20- 29 F10.6 deg DEdeg Declination in decimal degrees (J2000) 31- 36 F6.3 mag Vmag V band magnitude 38- 41 I4 K Teff Effective temperature 43- 46 F4.2 [cm/s2] log(g) Log of the surface gravity 48- 51 F4.2 km/s Vt Microturbulent velocity 53- 57 F5.2 [Sun] [Fe/H] Log of the Fe/H number abundance 59- 63 F5.2 [Sun] [O/Fe] ? Log of the O/Fe number abundance 65- 69 F5.2 [Sun] [Na/Fe] ? Log of the Na/Fe number abundance 71- 75 F5.2 [Sun] [Ba/Fe] Log of the Ba/Fe number abundance 77- 81 F5.2 [Sun] [La/Fe] ? Log of the La/Fe number abundance
Nomenclature notes: NNNNNN formats are <Cl* NGC 5139 WFI NNNNNN> in Simbad from Pancino et al., 2007, Cat. J/ApJ/661/L155 else <[MMP2011] RGB NNN> in Simbad. History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 18-Oct-2012
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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