J/A+A/670/A73 Li and 12C/13C of EXPRESS giants (Aguilera-Gomez+, 2023)
Evidence of extra-mixing in field giants as traced by lithium and
carbon isotope ratio.
Aguilera-Gomez C., Jones M.I., Chaname J.
<Astron. Astrophys. 670, A73 (2023)>
=2023A&A...670A..73A 2023A&A...670A..73A (SIMBAD/NED BibCode)
ADC_Keywords: Stars, giant ; Stars, horizontal branch ; Abundances ; Optical
Keywords: stars: evolution - stars: abundances
Abstract:
Lithium and the carbon isotope ratio 12C/13C can change during the
red giant branch as a result of extra-mixing. This is associated
usually with thermohaline mixing acting after the RGB bump. Peculiar
Li-enriched RGB stars might also be related to either enhanced
extra-mixing or pollution from external sources. We measure the Li
abundance and 12C/13C in a sample of 166 field giants targeted by
the EXPRESS radial velocity program to analyze the effects of
extra-mixing. We measure the abundances with spectral synthesis using
high-resolution and high signal-to-noise spectra. Multiple-epoch
observations needed for exoplanet detection are used to decrease the
effects of telluric contamination in 12C/13C measurements.
Description:
Stellar parameters, evolutionary stages (from Soto et al.,
2021A&A...647A.157S 2021A&A...647A.157S, Cat. J/A+A/647/A157), and measured Li and
12C/13C for 166 giants of the EXPRESS radial velocity program. We
use spectra obtained with FEROS, HARPS, and CHIRON. Li and 12/13C
are measured with spectral synthesis. A value for 12C/13C is
derived for each observation epoch to decrease the effect of telluric
contamination.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 111 166 Catalogue of parameters and measured Li and
12C/13C for the sample giants
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See also:
J/A+A/647/A157 : Stellar parameters of the EXPRESS sample (Soto+, 2021)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name HIP object name (HIPNNNNNN)
11- 16 F6.1 K Teff Effective temperature
18- 22 F5.1 K e_Teff Uncertainty on temperature
24- 28 F5.3 [cm/s2] logg Surface gravity
30- 34 F5.3 [cm/s2] e_logg Uncertainty on surface gravity
36- 40 F5.2 [-] [Fe/H] Metallicity
42- 46 F5.3 [-] e_[Fe/H] Uncertainty on metallicity
48- 51 F4.2 Msun Mass Stellar mass
53- 57 F5.3 Msun E_Mass Upper mass uncertainty
59- 63 F5.3 Msun e_Mass Lower mass uncertainty
65- 69 F5.2 Gyr Age Stellar age
71- 74 F4.2 [Lsun] logL Stellar luminosity
76- 80 F5.3 --- ProbRGB Probability of red giant branch
82- 84 A3 --- ES Evolutionary stage (1)
86 I1 --- l_A(Li) [0/1] Limit flag on A(Li) (2)
88- 92 F5.2 --- A(Li) Lithium abundance
94- 98 F5.3 --- A(Li)NLTE NLTE Lithium abundance
100-103 F4.1 --- 12C/13C ?=- Carbon isotope ratio
105-108 F4.1 --- s_12C/13C ?=- Standard deviation of 12C/13C
measurement
110-111 I2 --- o_12C/13C Number of 12C/13C measurements
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Note (1): Evolutionary stage is either RGB for red giant branch stars or HB for
Horizontal branch, based on ProbRGB.
Note (2): Upper limit flag on A(Li) is 0 if upper limit, 1 if measurement.
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Acknowledgements:
Claudia Aguilera-Gomez, craguile(at)uc.cl
(End) Patricia Vannier [CDS] 02-Dec-2022