J/A+A/614/A55 Lithium abundance in dwarfs & subgiants (Aguilera-Gomez+, 2018)
Lithium abundance patterns of late-F stars:
an in-depth analysis of the lithium desert.
Aguilera-Gomez C., Ramirez I., Chaname J.
<Astron. Astrophys. 614, A55 (2018)>
=2018A&A...614A..55A 2018A&A...614A..55A (SIMBAD/NED BibCode)
ADC_Keywords: Abundances ; Stars, G-type ; Stars, masses ; Stars, ages ;
Stars, F-type
Keywords: stars: abundances - stars: evolution
Abstract:
We address the existence and origin of the lithium (Li) desert, a
region in the Li-Teff plane sparsely populated by stars. Here we
analyze some of the explanations that have been suggested for this
region, including mixing in the late main sequence, a Li dip origin
for stars with low Li abundances in the region, and a possible
relation with the presence of planets. To study the Li desert, we
measured the atmospheric parameters and Li abundance of 227 late-F
dwarfs and subgiants, chosen to be in the Teff range of the desert
and without previous Li abundance measurements. Subsequently, we
complemented those with literature data to obtain a homogeneous
catalog of 2318 stars, for which we compute masses and ages. We
characterize stars surrounding the region of the Li desert. We
conclude that stars with low Li abundances below the desert are more
massive and more evolved than stars above the desert. Given the
unexpected presence of low Li abundance stars in this effective
temperature range, we concentrate on finding their origin. We conclude
that these stars with low Li abundance do not evolve from stars above
the desert: at a given mass, stars with low Li (i.e., below the
desert) are more metal-poor. Instead, we suggest that stars below the
Li desert are consistent with having evolved from the Li dip,
discarding the need to invoke additional mixing to explain this
feature. Thus, stars below the Li desert are not peculiar and are only
distinguished from other subgiants evolved from the Li dip in that
their combination of atmospheric parameters locates them in a range of
effective temperatures where otherwise only high Li abundance stars
would be found (i.e., stars above the desert).
Description:
In this work, we derive stellar parameters and lithium abundances of
227 stars. The spectra we used have high resolution (∼60000) and high
signal-to-noise ratio (S/N>100), and were obtained with either the
MIKE Spectrograph at Las Campanas Observatory, or with the Tull coude
spectrograph on the 2.7m Harlan J. Smith Telescope at McDonald
Observatory.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 52 227 Atmospheric parameters and Li abundances for
the 227 stars presented in this work
table3.dat 122 2318 Catalog of stellar parameters and Lithium
abundances
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See also:
J/A+A/363/239 : Lithium abundances in single giant stars (De Medeiros+, 2000)
J/A+A/371/943 : Lithium abundances for 185 main-sequence stars (Chen+, 2001)
J/A+A/409/251 : Li abundances and velocities in F and G stars (Mallik+, 2003)
J/A+A/538/A36 : Lithium abundances of bulge RGB stars (Lebzelter+, 2012)
J/ApJ/756/46 : Lithium abundances in HIP stars (Ramirez+, 2012)
J/ApJ/785/94 : Lithium abundances of a large sample of red giants (Liu+, 2014)
J/A+A/595/A18 : Lithium abundances in AMBRE stars (Guiglion+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [HIP]
4- 9 I6 --- HIP HIP identifier (NNNNNN)
10 A1 --- m_HIP [AB] Multiplicity index on HIP identifier
12- 15 I4 K Teff [5686/6617] Effective temperature
17- 18 I2 K e_Teff [20/85] Uncertainty in Teff
20- 23 F4.2 [cm/s2] logg [3.5/4.5] Log of the surface gravity logg
25- 28 F4.2 [cm/s2] e_logg [0/0.12] Uncertainty in logg
30- 34 F5.2 [-] [Fe/H] [-0.34/0.36] Metallicity [Fe/H]
36- 39 F4.2 [-] e_[Fe/H] [0.03/0.16] Uncertainty in [Fe/H]
41 A1 --- l_ALi Limit flag on A(Li)
44- 47 F4.2 --- ALi [0.5/3.51] Lithium abundance A(Li)
49- 52 F4.2 --- e_ALi [0.01/0.07]? Uncertainty in A(Li)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [HIP]
4- 9 I6 --- HIP HIP identifier (NNNNNN)
10 A1 --- m_HIP [AB] Multiplicity index on HIP identifier
12- 15 I4 K Teff [4153/7165] Effective temperature
17- 19 I3 K e_Teff [50/139] Uncertainty in Teff
21- 24 F4.2 [cm/s2] logg [3.43/4.74]?=9.99 Log of the surface gravity
26- 29 F4.2 [cm/s2] e_logg [0/0.44] Uncertainty in logg
31- 35 F5.2 [-] [Fe/H] [-2.3/0.62] Metallicity
37- 40 F4.2 [-] e_[Fe/H] [0.04/0.31] Uncertainty in [Fe/H]
42 A1 --- l_ALi Limit flag on A(Li)
44- 48 F5.2 --- ALi [-1.06/3.54] Lithium abundance A(Li)
50- 53 F4.2 --- e_ALi [0/0.83]? Uncertainty in A(Li)
55- 58 F4.2 Msun Mass [0.57/1.87]?=0 Star mass
60- 63 F4.2 Msun E_Mass ?=0 Upper limit uncertainty in Mass
65- 68 F4.2 Msun e_Mass ?=0 Lower limit uncertainty in Mass
70- 74 F5.2 Gyr Age [0.1/14.9]? Star age
76- 79 F4.2 Gyr E_Age [0/9.05]? Upper limit uncertainty in Age
81- 84 F4.2 Gyr e_Age [0/9.24]? Lower limit uncertainty in Age
86- 88 A3 --- n_Age Age determination method: iso=isochrones,
rot=rotation.
90- 92 A3 --- Pl [yes/no]? Known planet-host?
94-122 A29 --- Source References (1)
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Note (1): References as follows:
R12 = Ramirez et al., 2012, Cat. J/ApJ/756/46
B10 = Baumann et al., 2010, Cat. J/A+A/519/A87
G10 = Gonzalez et al., 2010, Cat. J/MNRAS/403/1368
I09 = Israelian et al., 2009Natur.462..189I 2009Natur.462..189I
LH06 = Luck & Heiter, 2006AJ....131.3069L 2006AJ....131.3069L
T10 = Takeda et al., 2010, Cat. J/A+A/515/A93
Gh10 = Ghezzi et al., 2010, Cat. J/ApJ/724/154
LR04 = Lambert & Reddy, 2004, Cat. J/MNRAS/349/757
DM14 = Delgado Mena et al., 2014, Cat. J/A+A/562/A92
DM15 = Delgado Mena et al., 2015, Cat. J/A+A/576/A69
G1415 = Gonzalez, 2014MNRAS.441.1201G 2014MNRAS.441.1201G and Gonzalez, 2015, Cat. J/MNRAS/446/1020
This = This Work
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Acknowledgements:
Claudia Aguilera Gomez, caguiler(at)astro.puc.cl
(End) Patricia Vannier [CDS] 15-Mar-2018