J/A+A/576/A69 Li abundances in F stars (Delgado Mena+, 2015)
Li abundances in F stars: planets, rotation, and Galactic evolution.
Delgado Mena E., Bertran De Lis S., Adibekyan V.Z., Sousa S.G.,
Figueira P., Mortier A., Gonzalez Hernandez J.I., Tsantaki M.,
Israelian G., Santos N.C.
<Astron. Astrophys., 576, A69-69 (2015)>
=2015A&A...576A..69D 2015A&A...576A..69D
ADC_Keywords: Stars, F-type ; Abundances
Keywords: stars: abundances - stars: fundamental parameters - stars: rotation -
stars: evolution - planets and satellites: formation -
planetary systems
Abstract:
We aim, on the one hand, to study the possible differences of Li
abundances between planet hosts and stars without detected planets at
effective temperatures hotter than the Sun, and on the other hand, to
explore the Li dip and the evolution of Li at high metallicities. We
present lithium abundances for 353 main sequence stars with and
without planets in the Teff range 5900-7200K. We observed 265 stars
of our sample with HARPS spectrograph during different planets search
programs. We observed the remaining targets with a variety of
high-resolution spectrographs. The abundances are derived by a
standard local thermodynamic equilibrium analysis using spectral
synthesis with the code MOOG and a grid of Kurucz ATLAS9 atmospheres.
We find that hot jupiter host stars within the Teff range 5900-6300K
show lower Li abundances, by 0.14dex, than stars without detected
planets. This offset has a significance at the level 7σ,
pointing to a stronger effect of planet formation on Li abundances
when the planets are more massive and migrate close to the star.
However, we also find that the average vsini of (a fraction of) stars
with hot jupiters is higher on average than for single stars in the
same Teff region, suggesting that rotational-induced mixing (and not
the presence of planets) might be the cause for a greater depletion of
Li. We confirm that the mass-metallicity dependence of the Li dip is
extended towards [Fe/H]∼0.4dex (beginning at [Fe/H]~-0.4dex for our
stars) and that probably reflects the mass-metallicity correlation of
stars of the same Teff on the main sequence. We find that for the
youngest stars (<1.5Gyr) around the Li dip, the depletion of Li
increases with vsini values, as proposed by rotationally-induced
depletion models. This suggests that the Li dip consists of fast
rotators at young ages whereas the most Li-depleted old stars show
lower rotation rates (probably caused by the spin-down during their
long lifes). We have also explored the Li evolution with [Fe/H] taking
advantage of the metal-rich stars included in our sample. We find that
Li abundance reaches its maximum around solar metallicity, but
decreases in the most metal-rich stars, as predicted by some models of
Li Galactic production.
Description:
Our baseline sample is 1111 FGK stars observed within the context of
the HARPS GTO programs. It is a combination of three HARPS subsamples
hereafter called HARPS-1 (Mayor et al., 2003Msngr.114...20M 2003Msngr.114...20M), HARPS-2
(Lo Curto et al., 2010, Cat. J/A+A/512/A48), and HARPS-4 (Santos et
al., 2011, Cat. J/A+A/526/A112). The individual spectra of each star
were reduced using the HARPS pipeline and then combined with IRAF2
after correcting for its radial velocity shift. The final spectra have
a resolution of R∼110000 and high signal-to-noise ratio (55% of the
spectra have a S/N higher than 200). The total sample is composed of
135 stars with planets and 976 stars without detected planets.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 78 36 Li abundances for stars with planets
from HARPS GTO samples
table4.dat 78 229 Li abundances for stars without detected planets
from HARPS GTO samples
table5.dat 78 88 Li abundances for planet hosts not belonging
to the HARPS-GTO sample
table6.dat 78 483 Li abundances for cool stars without detected
planets from HARPS GTO samples
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Byte-by-byte Description of file: table?.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Sample Sample (HARPS-2, HARPS-4, or blank) (3)
9- 19 A11 --- Star Star name
21- 24 I4 K Teff [4556/7212] Effective temperature
26- 29 F4.2 [cm/s2] logg [3.9/5] Surface gravity
31- 34 F4.2 km/s vt [0/3.1] Microturbulent velocity ξ
36- 40 F5.2 [Sun] [Fe/H] [-1.4/0.6] Metallicity
42- 46 F5.2 Gyr Age [0.1/12]?=- Age
48- 51 F4.2 Msun Mass [0.7/1.7]?=- Mass
53 A1 --- l_A(Li) Limit flag on A(Li)
54- 58 F5.2 [-] A(Li) [-1.1/3.4] Lithum abundance
60- 63 F4.2 [-] e_A(Li) [0.02/0.15]?=- rms uncertainty on A(Li)
65- 69 F5.2 km/s vsini [2/18]?=- Rotational velocity
71- 73 A3 --- Jhot [yes/no ] Hot jupiter? (blank when no planet)
75- 76 I2 --- Inst [1/11]? Instrument used (1)
78 A1 --- Ref Reference for the stellar parameters (2)
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Note (1): Flag for instrument used (table5) as follows:
1 = UVES
2 = HARPS
3 = FEROS
4 = SARG
5 = CORALIE
6 = NOT
7 = SOPHIE
8 = HIRES
9 = FIES
10 = ELODIE
11 = UES
Note (2): References as follows:
a = Mortier et al. (2013A&A...558A.106M 2013A&A...558A.106M, Cat. J/A+A/558/A106)
b = Santos et al. (2013A&A...556A.150S 2013A&A...556A.150S, Cat. J/A+A/556/A150)
c = Santos et al. (2004A&A...415.1153S 2004A&A...415.1153S, Cat. J/A+A/415/1153)
d = Sousa et al. (2006A&A...458..873S 2006A&A...458..873S, Cat. J/A+A/458/873)
e = Ammler-von Eiff et al. (2009A&A...507..523A 2009A&A...507..523A)
f = Santos et al. (2005A&A...437.1127S 2005A&A...437.1127S)
g = Santos et al. (2006A&A...458..997S 2006A&A...458..997S, Cat. J/A+A/458/997)
h = Moutou et al. (2006A&A...458..327M 2006A&A...458..327M)
i = da Silva et al. (2007A&A...473..323D 2007A&A...473..323D)
j = Molenda-Zakowicz et al. (2013MNRAS.434.1422M 2013MNRAS.434.1422M)
k = Bonomo et al. (2012A&A...538A..96B 2012A&A...538A..96B)
l = Pont et al. (2008A&A...487..749P 2008A&A...487..749P)
m = Udalski et al. (2008A&A...482..299U 2008A&A...482..299U)
s = Sousa et al. (2008A&A...487..373S 2008A&A...487..373S, Cat. J/A+A/487/373;
2011A&A...526A..99S 2011A&A...526A..99S, Cat. J/A+A/526/A99; and
2011A&A...533A.141S 2011A&A...533A.141S, Cat. J/A+A/533/A141)
Note (3): the samples are defined in Lo Curto et al. 2010 (J/A+A/512/A48,
HARPS-2) and Santo et al. 2011 (J/A+A/526/A112, HARPS-4).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 05-Jun-2015