J/ApJ/785/94 Lithium abundances of a large sample of red giants (Liu+, 2014)
The lithium abundances of a large sample of red giants.
Liu Y.J., Tan K.F., Wang L., Zhao G., Sato B., Takeda Y., Li H.N.
<Astrophys. J., 785, 94 (2014)>
=2014ApJ...785...94L 2014ApJ...785...94L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, giant ; Stars, G-type ; Stars, K-type ; Spectroscopy ;
Effective temperatures ; Abundances, [Fe/H] ; Stars, masses
Keywords: methods: data analysis - stars: abundances - stars: late type -
techniques: spectroscopic
Abstract:
The lithium abundances for 378 G/K giants are derived with non-local
thermodynamic equilibrium correction considered. Among these are 23 stars
that host planetary systems. The lithium abundance is investigated, as
a function of metallicity, effective temperature, and rotational
velocity, as well as the impact of a giant planet on G/K giants. The
results show that the lithium abundance is a function of metallicity
and effective temperature. The lithium abundance has no correlation
with rotational velocity at v sin i<10 km/s. Giants with planets
present lower lithium abundance and slow rotational velocity
(v sin i<4 km/s). Our sample includes three Li-rich G/K giants, 36
Li-normal stars, and 339 Li-depleted stars. The fraction of Li-rich
stars in this sample agrees with the general rate of less than 1% in
the literature, and the stars that show normal amounts of Li are
supposed to possess the same abundance at the current interstellar
medium. For the Li-depleted giants, Li-deficiency may have already
taken place at the main sequence stage for many intermediate mass
(1.5-5 M☉)G/K giants. Finally, we present the lithium abundance
and kinematic parameters for an enlarged sample of 565 giants using a
compilation of the literature, and confirm that the lithium abundance
is a function of metallicity and effective temperature. With the
enlarged sample, we investigate the differences between the lithium
abundance in thin-/thick-disk giants, which indicate that the lithium
abundance in thick-disk giants is more depleted than that in thin-disk
giants.
Description:
The sample stars analyzed here are comprised of 321 giants from the
Okayama Planet Search Program (Sato et al. 2003ApJ...597L.157S 2003ApJ...597L.157S) and 57
giants from the Xinglong Planet Search Program (Liu et al.
2008ApJ...672..553L 2008ApJ...672..553L). Both programs aim to detect planets around
intermediate mass G type (and early K type) giants. The spectra were
taken with the High Dispersion Echelle Spectrograph at Okayama
Astrophysical Observatory (OAO), which was equipped at the coude focus
of the 1.88 m telescope during 2008-2010. Before 2008 October, one CCD
system with wavelength coverage of 5000-6200 Å was used, and after that
the new mosaic 3 CCD system with wavelength a coverage of 4000-7540 Å
replaced it.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 69 565 Star name, NLTE result of lithium abundance for
sub-sample groups with Li detection, with upper
limit, and with planets, the UVW velocities,
and the thick-disk-to-thin disk ratio
table2.dat 58 378 The stellar parameters and lithium abundances
of 378 red giants
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See also:
J/A+A/538/A36 : Lithium abundances of bulge RGB stars (Lebzelter+, 2012)
J/ApJ/765/157 : Abundances of red giants in the Galactic bulge (Johnson+, 2013)
J/A+A/569/A55 : Abundances and vsini for 348 red giants (Adamow+, 2014)
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Stellar identifier (HD NNNNNN)
10- 14 F5.2 --- ALi-d ? NLTE Li abundance for Li-detected sub-sample
16- 21 F6.2 --- ALi-l ? Li abundance for sub-sample with upper limit
23- 28 F6.2 --- ALi-p ? NLTE Li abundance for sub-sample with planets
30- 36 F7.2 km/s U U Galactic velocity (1)
38- 44 F7.2 km/s V V Galactic velocity (1)
46- 56 F11.2 km/s W W Galactic velocity (1)
58- 69 F12.2 --- TD/D ? The thick-disk-to-thin disk ratio
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Note (1): A Solar motion of (U, V, W)Sun=(-10.00±0.36, +5.25±0.62,
+7.17±0.38) (Dehnen & Binney, 1998MNRAS.298..387D 1998MNRAS.298..387D) is adopted,
where the Galactic velocity component U is defined to be positive
towards the Galactic anticenter. The Galactic velocity components U,
V, and W of stars in our program are corrected to the local standard
of rest.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Stellar identifier (HD NNNNNN)
10- 13 I4 K Teff Effective temperature
15- 18 F4.2 [cm/s2] log(g) Log of the surface gravity
20- 24 F5.2 [-] [Fe/H] Metallicity
26- 29 F4.2 Msun M* Stellar mass
31- 35 F5.2 --- A1 ? LTE Li abundance in A1 sub-sample group
37- 41 F5.2 --- A2 ? LTE Li abundance in A2 sub-sample group
43- 47 F5.2 --- A3 ? LTE Li abundance in A3 sub-sample group
49- 53 F5.2 --- A4 ? LTE Li abundance in A4 sub-sample group
55- 58 F4.2 --- DelNLTE The NLTE correction
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 06-Jun-2017