J/A+A/539/A157 Li and Na in globular cluster M4 (Monaco+, 2012)
Lithium and sodium in the globular cluster M 4. Detection of a Li-rich
dwarf star: preservation or pollution?
Monaco L., Villanova S., Bonifacio P., Caffau E., Geisler D., Marconi G.,
Momany Y., Ludwig H.-G.
<Astron. Astrophys., 539, A157 (2012)>
=2012A&A...539A.157M 2012A&A...539A.157M
ADC_Keywords: Clusters, globular; Stars, dwarfs ; Abundances
Keywords: nuclear reactions, nucleosynthesis, abundances - stars: abundances -
stars: Population II - galaxies: abundances -
globular clusters: individual: M4 - cosmology: observations
Abstract:
The abundance inhomogeneities of light elements observed in globular
clusters (GCs), and notably the ubiquitous Na-O anti-correlation, are
generally interpreted as evidence that GCs comprise several
generations of stars. There is an on-going debate as to the nature of
the stars, which produce the inhomogeneous elements, and investigating
the behavior of several elements is a way to shed new light on this
problem.
We aim at investigating the Li and Na content of the GC M4, that is
known to have a well defined Na-O anti-correlation.
We obtained moderate resolution (R=17000-18700) spectra for 91
main sequence (MS)/sub-giant branch stars of M4 with the Giraffe
spectrograph at the FLAMES/VLT ESO facility. Using model atmospheres
analysis we measured lithium and sodium abundances.
Description:
We observed stars along the M4 MS and SGB using the FLAMES/GIRAFFE
spectrograph at ESO Paranal. Observations were conducted in service
mode between April and July 2010 using the HR12 and HR15N settings.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 68 91 Basic data for MS/SGB stars studied in this paper
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See also:
J/ApJ/443/124 : Radial Velocities of Stars in M4 (Peterson+ 1995)
J/PAZh/22/847 : Identification and coordinates in M4 (Shokin+, 1996)
J/AJ/114/189 : M4 CCD photometry (Alcaino+, 1997)
J/ApJS/120/265 : HST photometry of M4 (Ibata+, 1999)
J/AJ/124/1486 : M4 UBV color-magnitude diagrams (Mochejska+, 2002)
J/AJ/127/2771 : HST proper-motions of M4 main-sequence stars (Richer+, 2004)
J/ApJ/689/1031 : Heavy element abundances in giant stars (Yong+, 2008)
J/A+A/490/625 : Abundances of NGC 6121 red giants (Marino+, 2008)
J/MNRAS/412/81 : Lithium abundance in M4 red giants (Mucciarelli+, 2011)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Seq Sequential number
7- 8 I2 h RAh Right ascension (J2000)
10- 11 I2 min RAm Right ascension (J2000)
13- 17 F5.2 s RAs Right ascension (J2000)
19 A1 --- DE- Declination sign (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 30 F5.2 arcsec DEs Declination (J2000)
32- 35 I4 K Teff Effective temperature
37- 40 F4.2 [cm/s2] logg Surface gravity
42- 45 F4.2 km/s xi Turbulent velocity ξ
47- 50 F4.2 [-] A(Fe) [6.12/6.36] Fe abundance
52- 55 F4.2 [-] A(Na) [4.94/5.52] Na abundance
57- 60 F4.2 [-] A(Li) [0.86/2.87] Li abundance
62- 64 I3 0.1pm EW(Li) [8/114] Li equivalent width
66- 68 I3 --- S/N Spectral signal-to-noise at the lithium line
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 29-May-2012