J/A+A/464/953 Abundances of red giants in NGC 6441 (Gratton+, 2007)
Na-O anticorrelation and horizontal branches.
V. The Na-O anticorrelation in NGC 6441 from Giraffe spectra.
Gratton R.G., LucatelloS., Bragaglia A., Carretta E., Cassisi S.,
Momany Y., Pancino E., Valenti E., Caloi V., Claudi R., D'Antona F.,
Desidera S., Francois P., James G., Moehler S., Ortolani S., Pasquini L.,
Piotto G., Recio-Blanco A.
<Astron. Astrophys. 464, 953 (2007)>
=2007A&A...464..953G 2007A&A...464..953G
ADC_Keywords: Clusters, globular ; Stars, population II ; Equivalent widths ;
Radial velocities
Keywords: stars: abundances - stars: atmospheres - stars: Population II -
Galaxy: globular clusters: general -
Galaxy: globular clusters: individual: NGC 6441
Abstract:
We present an analysis of FLAMES-Giraffe spectra for several bright
giants in NGC 6441, to investigate the presence and extent of the Na-O
anticorrelation in this anomalous globular cluster.
The field of NGC 6441 is very crowded, with severe contamination by
foreground (mainly bulge) field stars. Appropriate membership criteria
were devised to identify a group of 25 likely cluster members among
the about 130 stars observed. Combined with the UVES data obtained
with the same observations (Gratton et al., 2006, Cat.
J/A+A/455/271), high dispersion abundance analyses are now available
for a total of 30 stars in NGC 6441, 29 of them having data for both O
and Na. The spectra were analyzed by a standard line analysis
procedure; care was taken to minimize the impact of the differential
interstellar reddening throughout the cluster, and to extract reliable
information from crowded, and moderately high S/N (30-70), moderately
high resolution (R∼23000) spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 76 25 Photometry and spectroscopic data for stars
observed with Giraffe
table3.dat 38 2375 Equivalent Widths from Giraffe spectra
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See also:
J/A+A/455/271 : Abundances of red giants in NGC 6441 (Gratton+, 2006)
J/A+A/464/927 : Abundances of red giants in NGC 6752 (Carreta+, 2007)
J/A+A/464/939 : Abundances of red giants in NGC 6218 (Carreta+, 2007)
J/A+A/464/967 : Abundances of red giants in NGC 6388 (Carreta+, 2007)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 I7 --- Star Sequential number of the star
9- 13 A5 --- Gratings [11+13 ] Grating(s) used
15- 22 F8.4 deg RAdeg Right ascension (J2000) in decimal degrees
24- 31 F8.4 deg DEdeg Declination (J2000) in decimal degrees
33- 35 I3 arcsec Dist Distance from the cluster center
37- 42 F6.3 mag Vmag Johnson V magnitude
44- 48 F5.3 mag V-Ic Johnson-Cousins V-Ic colour index
50- 54 F5.3 mag V-K ? Johnson V-K colour index
56- 59 F4.1 km/s RV Radial velocity
61- 62 I2 --- S/NHR11 ? HR11 signal-to-noise ratio
64- 65 I2 --- S/NHR13 ? HR13 signal-to-noise ratio
67- 70 F4.1 0.1pm e_EW rms uncertainty on equivalent width (mÅ)
72- 76 F5.2 [Sun] [Fe/H] Metallicity
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 I7 --- Star Sequential number of the star
9- 12 F4.1 --- Ion Element and ionisation stage, e.g. 26.1 = FeI
14- 20 F7.2 0.1nm Lambda Wavelength of the line
22- 25 F4.2 eV EP Potential energy
27- 32 F6.2 --- loggf Oscillator strength
34- 38 F5.1 0.1pm EW ? Equivalent width (mÅ)
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Acknowledgements:
Sara Lucatello, sara.lucatello(at)oapd.inaf.it
References:
Carreta et al., Paper I, NGC 2808 2006A&A...450..523C 2006A&A...450..523C
Carreta et al., Paper II, NGC 6752 2007A&A...464..927C 2007A&A...464..927C, Cat. J/A+A/464/927
Gratton et al., Paper III, NGC 6441 2006A&A...455..271G 2006A&A...455..271G, Cat. J/A+A/455/271
Carreta et al., Paper IV, NGC 6218 2007A&A...464..939C 2007A&A...464..939C, Cat. J/A+A/464/939
Carreta et al., Paper VI, NGC 6388 2007A&A...464..967C 2007A&A...464..967C, Cat. J/A+A/464/967
(End) Patricia Vannier [CDS] 12-Mar-2007