J/A+A/668/A49 Lithium curves of growth (Franciosini+, 2022)
The Gaia-ESO Survey: Lithium measurements and new curves of growth.
Franciosini E., Randich S., de Laverny P., Biazzo K., Feuillet D.K.,
Frasca A., Lind K., Prisinzano L., Tautvaisiene G., Lanzafame A.C.,
Smiljanic R., Gonneau A., Magrini L., Pancino E., Guiglion G., Sacco G.G.,
Sanna N., Gilmore G., Bonifacio P., Jeffries R.D., Micela M., Prusti T.,
Alfaro E.J., Bensby T., Bragaglia A., Francois P., Korn A.J., Van Eck S.,
Bayo A., Bergemann M., Carraro G., Heiter U., Hourihane A., Jofre P.,
Lewis J., Martayan C., Monaco L., Morbidelli L., Worley C.C., Zaggia S.
<Astron. Astrophys. 668, A49 (2022)>
=2022A&A...668A..49F 2022A&A...668A..49F (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; Abundances ; Spectroscopy
Keywords: surveys - methods: data analysis - stars: abundances -
stars: late-type
Abstract:
The Gaia-ESO Survey (GES) is a large public spectroscopic survey that
was carried out using the multi-object FLAMES spectrograph at the VLT.
The survey provides accurate radial velocities, stellar parameters and
elemental abundances for ∼115000 stars in all Milky Way components.
In this paper we describe the method adopted in the final data release
to derive lithium equivalent widths (EWs) and abundances.
Lithium EWs were measured using two different approaches for FGK and
M-type stars, to account for the intrinsic differences in the spectra.
For FGK stars we fitted the lithium line using Gaussian components,
while direct integration over a predefined interval was adopted for
M-type stars. Care was taken to ensure continuity between the two
regimes. Abundances were derived using a new set of homogeneous curves
of growth that were derived specifically for GES, and were measured on
a synthetic spectral grid consistently with the way the EWs were
measured. The derived abundances were validated by comparison with
those measured by other analysis groups using different methods.
Lithium EWs were measured for ∼40000 stars, and abundances could be
derived for ∼38000 of them. The vast majority of the measures (80%)
have been obtained for stars in open cluster fields. The remaining
objects are stars in globular clusters, or field stars in the Milky
way disc, bulge and halo. The GES dataset of homogeneous lithium
abundances described here will be valuable for our understanding of
several processes, from stellar evolution and internal mixing in stars
at different evolutionary stages to Galactic evolution.
Description:
Tables A.1 and A.2 provide the lithium curves of growth for FGK stars,
and the corresponding corrections for the Fe blend (to be applied to
the measured EW when the Li and Fe line cannot be deblended, before
computing the abundance). Both the curves of growth and the blend
corrections are given as a function of effective temperature, gravity
and metallicity. Table A.3 provides the curves of growth for M-type
stars, to convert the measured pseudo-EWs into abundances. The M-type
curves of growth include also a dependency on the projected rotational
velocity.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 29 36209 Lithium curves of growth for FGK stars
tablea2.dat 23 1465 Blend corrections for FGK stars
tablea3.dat 35 86960 Lithium curves of growth for M-type stars
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 6 F6.1 K Teff [4000/8000] Effective temperature
8- 10 F3.1 [cm/s2] logg [0.5/5.0] Surface gravity
12- 16 F5.2 --- [Fe/H] [-2.5/0.5] Metallicity
18- 21 F4.1 --- A(Li) [-1.0/4.0] Lithium abundance
23- 29 F7.2 0.1pm EW(Li) Lithium equivalent width (mAngstroem)
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 6 F6.1 K Teff [4000/8000] Effective temperature
8- 10 F3.1 [cm/s2] logg [0.5/5.0] Surface gravity
12- 16 F5.2 --- [Fe/H] [-2.5/0.5] Metallicity
18- 23 F6.2 0.1pm EW(Fe) Equivalent width of Fe blend (mAngstroem)
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 6 F6.1 K Teff [3000/4500] Effective temperature
8- 10 F3.1 [cm/s2] logg [0.5/5.0] Surface gravity
12- 16 F5.2 --- [Fe/H] [-1.5/0.5] Metallicity
18- 22 F5.1 km/s vsini Projected rotational velocity
24- 27 F4.1 --- A(Li) [-1.0/4.0] Lithium abundance
29- 35 F7.2 0.1pm pEW Lithium pesudo-equivalent width (mAngstroem)
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Acknowledgements:
Elena Franciosini, elena.franciosini(at)inaf.it
(End) E. Franciosini [INAF/Arcetri Obs., Italy], P. Vannier [CDS] 11-Oct-2022