J/A+A/547/A106 Li abundances in the FGK dwarfs (Mishenina+, 2012)
Activity and the Li abundances in the FGK dwarfs.
Mishenina T.V., Soubiran C., Kovtyukh V.V., Katsova M.M., Livshits M.A.
<Astron. Astrophys. 547, A106 (2012)>
=2012A&A...547A.106M 2012A&A...547A.106M
ADC_Keywords: Stars, late-type ; Stars, dwarfs ; Abundances
Keywords: stars: late type - stars: fundamental parameters -
stars: abundances - stars: rotation - stars: activity
Abstract:
The aim of the present study is to determine the Li abundances for a
large set of the FGK dwarfs and to analyse the connections between the
Li content, stellar parameters, and activity. The atmospheric
parameters, rotational velocities and the Li abundances were
determined from a homogeneous collection of the echelle spectra with
high resolution and a high signal-to-noise ratio. The rotational
velocities vsini were determined by calibrating the cross-correlation
function. The effective temperatures Teff were estimated by the line
depth ratio method. The surface gravities logg were computed by two
methods: the iron ionization balance and the parallax. The LTE Li
abundances were computed using synthetic spectra method. The behaviour
of the Li abundance was examined in correlation with Teff, [Fe/H], as
well as with vsini and the level of activity in three stellar groups
of the different temperature range. The stellar parameters and the Li
abundances are presented for 150 slow rotating stars of the lower part
of MS. The studied stars show a decline in the Li abundance with
decreasing temperature Teff and a significant spread, which should be
due to the difference of age of stars. The correlations between the Li
abundances, rotational velocities vsini, and the level of the
chromospheric activity were discovered for the stars with
6000>Teff>5700K, and it is tighter for the stars with 5700>Teff>5200K.
The target stars with Teff<5200K do not show any correlation between
log A(Li) and vsini. The relationship between the chromospheric and
coronal fluxes in active with detected Li as well as in less active
stars gives a hint that there exist different conditions in the action
of the dynamo mechanism in those stars.
We found that the Li-activity correlation is evident only in a
restricted temperature range and the Li abundance spread seems to be
present in a group of low chromospheric activity stars that also show
a broad spread in the chromospheric vs. coronal activity.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 77 151 The stellar parameters, determined in the
present study
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See also:
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
J/MNRAS/253/610 : Li abundances for 81 F dwarfs (Lambert+, 1991)
J/AJ/105/2299 : Li abundance of solar-type stars. II. (Soderblom+, 1993)
J/AJ/111/439 : Chromospheric emission in late-type stars. (Henry+ 1996)
J/A+A/409/251 : Li abundances and velocities in F and G stars (Mallik+, 2003)
J/ApJS/152/261 : Chromospheric Ca II emission in nearby stars (Wright+, 2004)
J/PASJ/57/45 : Lithium abundances of F-K stars (Takeda+, 2005)
J/A+A/468/663 : Li abundances in solar-analog stars (Takeda+, 2007)
J/A+A/521/A12 : RVs of nearby late-type stars (Maldonado+, 2010)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- HD/BD HD/BD name of star
12- 15 I4 K Teff Mean effective temperature of the star
17- 20 F4.2 [cm/s2] logg1 Gravity spectroscopic
22- 25 F4.2 [cm/s2] logg2 ?=- Gravity astrometric
27- 31 F5.2 [-] [Fe/H] ?=- Metallicity
33- 37 F5.2 km/s vsini ?=- Rotation velocity
39- 45 A7 --- Type Object type from SIMBAD
47- 51 F5.2 --- RX ?=- X-ray emission adopted from ROSAT
catalogs or estimated from ROSAT archive data
53- 57 F5.2 [-] logR'HK ?=- Chromospheric activity index
59- 66 A8 --- Ref Reference (1)
68 A1 --- l_logA(Li) Limit flag on logA(Li)
69- 73 F5.2 [-] logA(Li) Abundance of Li
74 A1 --- u_logA(Li) Uncertainty flag on logA(Li)
76- 77 A2 --- Act [A wA] High or weak class of activity (2)
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Note (1): References as follows:
W04 = Wright et al., 2004, Cat. J/ApJS/152/261
H96 = Henry et al., 1996, Cat. J/AJ/111/439
H07 = Hall et al., 2007AJ....133..862H 2007AJ....133..862H
B95 = Baliunas et al., 1995ApJ...438..269B 1995ApJ...438..269B
M10 = Maldonado et al. 2010, Cat. J/A+A/521/A12
Note (2): Class of activity as follows:
A = stars with high levels of the solar-type activity
wA = stars with weak levels of the solar-type activity
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Acknowledgements:
T. Mishenina, tamar(at)deneb1.odessa.ua,
V. Kovtyukh, val(at)deneb1.odessa.ua
(End) T. Mishenina, V. Kovtyukh [ODESSA], Patricia Vannier [CDS] 25-Oct-2012