J/A+A/651/A84 Li abundance and mixing in giant stars (Magrini+, 2021)
The Gaia-ESO survey: Mixing processes in low-mass stars traced by
lithium abundance in cluster and field stars.
Magrini L., Lagarde N., Charbonnel C., Franciosini E., Randich S.,
Smiljanic R., Casali G., Viscasillas Vazquez C., Spina L., Biazzo K.,
Pasquini L., Bragaglia A., Van der Swaelmen M., Tautvaisiene G., Inno L.,
Sanna N., Prisinzano L., Degl'Innocenti S., Prada Moroni P.,
Roccatagliata V., Tognelli E., Monaco L., de Laverny P., Delgado-Mena E.,
Baratella M., D'Orazi V., Vallenari A., Gonneau A., Worley C.,
Jimenez-Esteban F., Jofre P., Bensby T., Francois P., Guiglion G., Bayo A.,
Jeries R.D., Binks A.S., Gilmore G., Damiani F., Korn A., Pancino E.,
Sacco G.G., Hourihane A., Morbidelli L., Zaggia S.
<Astron. Astrophys. 651, A84 (2021)>
=2021A&A...651A..84M 2021A&A...651A..84M (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, open ; Stars, giant ; Abundances
Keywords: stars: abundances - stars: evolution -
open clusters and associations: general
Abstract:
We aim to constrain the mixing processes in low-mass stars by
investigating the behaviour of the Li surface abundance after the main
sequence. We take advantage of the data from the sixth internal data
release of Gaia-ESO, idr6, and from the Gaia Early Data Release 3,
EDR3.
We selected a sample of main-sequence, sub-giant, and giant stars in
which the Li abundance is measured by the Gaia-ESO survey. These stars
belong to 57 open clusters with ages from 130Myr to about 7Gyr and
to Milky Way fields, covering a range in [Fe/H] between -1.0 and
+0.5dex, with few stars between -1.0 and -2.5dex. We studied the
behaviour of the Li abundances as a function of stellar parameters. We
inferred the masses of giant stars in clusters from the main-sequence
turn-off masses, and for field stars through comparison with stellar
evolution models using a maximum likelihood technique. We compared the
observed Li behaviour in field giant stars and in giant stars
belonging to individual clusters with the predictions of a set of
classical models and of models with mixing induced by rotation and
thermohaline instability.
The comparison with stellar evolution models confirms that classical
models cannot reproduce the observed lithium abundances in the
metallicity and mass regimes covered by the data. The models that
include the effects of both rotation-induced mixing and thermohaline
instability account for the Li abundance trends observed in our sample
in all metallicity and mass ranges. The differences between the
results of the classical models and of the rotation models largely
differ (up to∼2 dex), making lithium the best element with which to
constrain stellar mixing processes in low-mass stars. We discuss the
nature of a sample of Li-rich stars.
We demonstrate that the evolution of the surface abundance of Li in
giant stars is a powerful tool for constraining theoretical stellar
evolution models, allowing us to distinguish the effect of different
mixing processes. For stars with well-determined masses, we find a
better agreement of observed surface abundances and models with
rotation-induced and thermohaline mixing. Rotation effects dominate
during the main sequence and the first phases of the
post-main-sequence evolution, and the thermohaline induced mixing
after the bump in the luminosity function.
Description:
We exploited a sample of giant stars with Li measurements in Gaia-ESO
IDR6 to investigate the evolution of A(Li) from the MSTO to the giant
phase. We combined the Gaia-ESO data with Gaia EDR3 to obtain the
distances and stellar luminosities. We compared our lithium abundances
with literature values and found a good agreement.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 106 71 Parameters of the Li-rich giant stars in the field
tablea1.dat 67 57 Parameters of our sample of open clusters from
Gaia-ESO IDR6
tablea2.dat 101 4212 Cluster member stars
tablea3.dat 114 7369 Field stars
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See also:
J/A+A/566/A50 : Classification of stellar spectra 644-681nm (Damiani+, 2014)
J/A+A/640/A1 : Portrait Galactic disc (Cantat-Gaudin+, 2020)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- GESField Gaia ESO Field
12- 27 A16 --- CName Gaia ESO ID (HHMMSSss+DDMMSSs)
29- 48 A20 --- Setup Gaia ESO SETUP
50- 53 I4 K Teff Effective temperature
55- 57 I3 K e_Teff Error on effective temperature
59- 62 F4.2 cm/s2 logg ?=- Surface gravity
64- 67 F4.2 cm/s2 e_logg ?=- Error on Surface gravity
69- 73 F5.2 [-] [Fe/H] ?=- Iron abundance on the solar scale
75- 78 F4.2 [-] e_[Fe/H] ?=- Error on Iron abundance on the solar scale
80- 84 F5.2 km/s vsini Projected rotational velocity
86- 88 F3.1 km/s e_vsini Error on projected rotational velocity
90- 93 F4.2 --- Li1 Lithium abundance 12+log(Li/H)
95- 98 F4.2 --- e_Li1 Error on Lithium abundance
100-106 A7 --- Other Literature identification (1)
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Note (1): Literature identification as follows:
CASEY16 = Casey et al. (2016MNRAS.461.3336C 2016MNRAS.461.3336C)
SMI18 = Smiljanic et al. (2018A&A...617A...4S 2018A&A...617A...4S)
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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- 2 I2 --- ID [1/57] Identification number of clusters
4- 13 A10 --- Cluster Cluster Name in the Gaia ESO catalogue
14 A1 --- n_Cluster [ab] Note on Cluster (1)
16- 19 I4 Myr Age Cluster age from Cantat-Gaudin et al.
(2020A&A...640A...1C 2020A&A...640A...1C, Cat. J/A+A/640/A1)
21- 25 I5 pc Dist Cluster distance from Cantat-Gaudin et al.
(2020A&A...640A...1C 2020A&A...640A...1C, Cat. J/A+A/640/A1)
27- 30 F4.1 kpc Rgc Galactocentric distance from Cantat-Gaudin et
al. (2020A&A...640A...1C 2020A&A...640A...1C, Cat. J/A+A/640/A1)
32- 36 F5.1 km/s rv Mean cluster radial velocity
38- 40 F3.1 km/s e_rv ?=- Error on the Mean radial velocity
42- 46 F5.2 [-] [Fe/H]m Mean cluster metallicity in the solar scale
48- 51 F4.2 [-] e_[Fe/H]m ?=- Error on the Mean cluster metallicity
53- 55 F3.1 Msun MMSTO Main Sequence Turn Off (MSTO) mass
57- 60 F4.2 Gyr AgeIso Age of the Isochrone used to compute the MSTO
62- 67 F6.4 --- ZIso Metallicity (by mass) of the Isochrone used
to compute the MSTO
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Note (1): Note on Cluster as follows:
a = only one star
b = only stars with logg>2.8
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Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- CName Gaia ESO ID (HHMMSSss+DDMMSSs)
18- 27 A10 --- GESField Gaia ESO Field
29- 34 F6.1 K Teff Effective Temperature
36- 38 I3 K e_Teff Error on the Effective Temperature
40- 43 F4.2 [cm/s] logg Surface gravity
45- 48 F4.2 [cm/s] e_logg Error on Surface gravity
50- 54 F5.2 [-] [Fe/H] Iron abundance on the solar scale
56- 59 F4.2 [-] e_[Fe/H] Error on Iron abundance on the solar scale
61 A1 --- l_Li1 Upper limit flag for Li1
62- 66 F5.2 --- Li1 Lithium abundance
69- 72 F4.2 --- e_Li1 ?=- Error on Lithium abundance
74- 79 F6.4 --- Gamma ?=- Gravity index defined in Damiani et al.
(2014A&A...566A..50D 2014A&A...566A..50D, Cat. J/A+A/566/A50)
81- 86 E6.4 --- e_Gamma ?=- Error on the Gravity index defined in
Damiani et al. (2014A&A...566A..50D 2014A&A...566A..50D,
Cat. J/A+A/566/A50)
88- 92 F5.2 [Lsun] logL ?=- Stellar Luminosity in log
94- 97 F4.2 [Lsun] e_logL ?=- Error on the stellar Luminosity in log
99-101 F3.1 Msun MMSTO Main Sequence Turn Off mass
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- CName Gaia ESO ID (HHMMSSss+DDMMSSs)
18- 29 A12 --- GESField Gaia ESO Field
33- 36 I4 K Teff Effective Temperature
38- 40 I3 K e_Teff Error on the Effective Temperature
42- 45 F4.2 [cm/s2] logg ?=- Surface gravity
47- 50 F4.2 [cm/s2] e_logg ?=- Error on Surface gravity
52- 56 F5.2 [Sun] [Fe/H] Iron abundance on the solar scale
58- 61 F4.2 [Sun] e_[Fe/H] Error on Iron abundance on the solar scale
63 A1 --- l_Li1 Upper limit flag on Li1
64- 68 F5.2 --- Li1 Lithium abundance
71- 74 F4.2 --- e_Li1 ?=- Error on Lithium abundance
76- 81 F6.4 --- Gamma ?=- Gravity index defined in Damiani et al.
(2014A&A...566A..50D 2014A&A...566A..50D, Cat. J/A+A/566/A50)
83- 88 E6.4 --- e_Gamma ?=- Error on the Gravity index defined in
Damiani et al. (2014A&A...566A..50D 2014A&A...566A..50D,
Cat. J/A+A/566/A50)
90- 94 F5.2 [Lsun] logL Stellar Luminosity in log
96- 99 F4.2 [Lsun] e_logL Error on the stellar Luminosity in log
101-104 F4.2 Msun Mass Mass
106-109 F4.2 Msun E_Mass Error (positive) on the mass
111-114 F4.2 Msun e_Mass Error (negative) on the mass
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Acknowledgements:
Laura Magrini, laura.magrini(at)inaf.it
(End) Patricia Vannier [CDS] 07-Jul-2021