J/A+A/657/A33 Lithium in the LRGB of 5 globular clusters (Aguilera-Gomez+, 2022)
Lithium in the lower red giant branch of five Galactic globular clusters.
Aguilera-Gomez C., Monaco L., Mucciarelli A., Salaris M., Villanova S.,
Pancino E.
<Astron. Astrophys. 657, A33 (2022)>
=2022A&A...657A..33A 2022A&A...657A..33A (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Stars, giant ; Abundances ; Optical
Keywords: globular clusters: general - stars: abundances -
primordial nucleosynthesis - stars: chemically peculiar
Abstract:
Lithium is one of the few elements produced during the Big Bang
Nucleosynthesis in the early universe. Moreover, its fragility makes
it useful as a proxy for stellar environmental conditions. As such,
the lithium abundance in old systems is at the core of different
astrophysical problems.
Stars in the lower red giant branch allow studying globular clusters
where main sequence stars are too faint to be observed. We use these
stars to analyze the initial Li content of the clusters and compare it
to cosmological predictions, to measure spreads in Li between
different stellar populations, and to study signs of extra depletion
in these giants.
Description:
Stellar parameters, lithium abundances, and sodium abundances in red
giant branch stars of the 5 globular clusters NGC4590, NGC6809,
NGC6656, NGC3201, and NGC6838. These are obtained by the analysis of
GIRAFFE spectra. Stellar parameters are measured using photometry,
while lithium and sodium abundances are derived matching synthetic
spectra to the LiI resonance doublet and the Na D doublet
respectively.
Objects:
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RA (2000) DE Designation(s)
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10 17 36.82 -46 24 44.9 NGC3201 = NGC 3201
12 39 27.98 -26 44 38.6 NGC4590 = M 68
18 36 23.94 -23 54 17.1 NGC6656 = M 22
19 39 59.71 -30 57 53.1 NGC6809 = M 55
19 53 46.49 +18 46 45.1 NGC6838 = M 71
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 118 348 Data for the RGB stars of 5 globular clusters
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See also:
J/MNRAS/485/3042 : UBVRI photometry in 48 globular clusters (Stetson+, 2019)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Cluster Globular cluster name
9- 27 I19 --- GaiaEDR3 Source identifier from Gaia-EDR3
29- 34 I6 --- Stetson Source identifier from Stetson et al.,
2019, Cat. J/MNRAS/485/3042
36- 44 F9.5 deg RAdeg Right ascension (J2000)
46- 54 F9.5 deg DEdeg Declination (J2000)
56- 59 I4 K Teff Effective temperature
61- 64 F4.2 [cm/s2] logg Surface gravity
66- 69 F4.2 km/s vt Microturbulent velocity
71- 74 F4.2 [-] e_A(Li) ? rms uncertainty on A(Li)
75 A1 --- f_A(Li) Upper limit flag on A(Li)
76- 80 F5.2 [-] A(Li)NLTE NLTE Lithium abundance
82- 86 F5.2 [-] A(Li)LTE LTE Lithium abundance
88- 92 F5.2 [Sun] [Na/Fe]NLTE ?=- Relative NLTE abundance [Na/Fe]
94- 98 F5.2 [Sun] [Na/Fe]LTE ?=- Relative LTE abundance [Na/Fe]
100-105 F6.3 mag Vmag Johnson V magnitude
107-112 F6.3 mag Imag Johnson I magnitude
114-118 F5.1 --- SNR Signal-to-noise ratio
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Acknowledgements:
Claudia Aguilera-Gomez, claudia.aguilera(at)mail.udp.cl
(End) Patricia Vannier [CDS] 07-Oct-2021