J/AJ/159/174 Parameters & abundances for Hyades/Field G-K dwarfs (Takeda+, 2020)
Spectroscopic determination of stellar parameters and oxygen abundances for
Hyades/Field G-K dwarfs.
Takeda Y., Honda S.
<Astron. J., 159, 174 (2020)>
=2020AJ....159..174T 2020AJ....159..174T
ADC_Keywords: Stars, dwarfs; Spectra, optical; Effective temperatures;
Abundances
Keywords: Stellar abundances ; Stellar atmospheres ;
Fundamental parameters of stars ; Late-type stars ; Open star clusters
Abstract:
It has been suggested that Fe abundances of K dwarfs derived from FeI
and FeII lines show considerable discrepancies, and oxygen abundances
determined from high-excitation OI-7771-5 triplet lines are
appreciably overestimated (the problem becoming more serious toward
lower Teff), which, however, has not yet been widely confirmed. With
the aim of clarifying this issue, we spectroscopically determined the
atmospheric parameters of 148 G-K dwarfs (Hyades cluster stars and
field stars) by assuming the classical FeI/FeII ionization equilibrium
as usual, and determined their oxygen abundances by applying the
non-local thermal equilibrium spectrum fitting analysis to OI-7771-5
lines. It turned out that the resulting parameters did not show any
significant inconsistency with those determined by other methods (for
example, the mean differences in Teff and logg from the
well-determined solutions of Hyades dwarfs are mostly ≲100K and
≲0.1dex). Likewise, the oxygen abundances of Hyades stars are around
[O/H]~+0.2dex (consistent with the metallicity of this cluster)
without exhibiting any systematic Teff-dependence. Accordingly, we
conclude that parameters can be spectroscopically evaluated to a
sufficient precision in the conventional manner (based on the
Saha-Boltzmann equation for FeI/FeII) and oxygen abundances can be
reliably determined from the OI-7771-5 triplet for K dwarfs as far as
stars of Teff≳4500K are concerned. We suspect that previously
reported strongly Teff-dependent discrepancies may have stemmed mainly
from overestimation of weak-line strengths and/or improper Teff scale.
Description:
As the target stars of this investigation, we adopted a sample of 148
dwarfs (consisting of 47 Hyades cluster stars and 101 field stars).
Our spectroscopic observations for 118 stars were done in four runs
over 2010-2011 (2010-April/May, 2010-August, 2010-November/December,
and 2011-November) using the HIgh Dispersion Echelle Spectrograph
(HIDES) placed at the coude focus of the 188cm reflector at Okayama
Astrophysical Observatory. HIDES enabled us to obtain an echellogram
covering ∼5100-8800Å with a resolving power of R∼67000. The
observations for the remaining 30 stars were done on 2014-September-9
with the High Dispersion Spectrograph at the Nasmyth platform of the
8.2m Subaru Telescope, by which high-dispersion spectra with a
resolution of R∼80000 covering ∼5100-7800Å were obtained.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 189 148 Basic data, parameters, and abundance results of
148 program stars
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/367/111 : A Hipparcos study of the Hyades cluster (de Bruijne+, 2001)
J/A+A/394/927 : Age-metallicity relation for nearby stars (Ibukiyama+, 2002)
J/MNRAS/336/879 : G and K dwarfs UBV(RI)c and ubvy photometry (Kotoneva+, 2002)
J/A+A/402/343 : IR O I triplet, [OI] lines in F-K dwarfs/giants (Takeda,2003)
J/A+A/420/183 : Spectro. survey in solar neighborhood (Allende Prieto+, 2004)
J/ApJ/602/L117 : Oxygen in Pleiades and M34 dwarfs (Schuler+, 2004)
J/PASJ/57/65 : CNO abundances of solar-type stars (Takeda+, 2005)
J/PASJ/57/27 : Atmospheric parameters of nearby F-K stars (Takeda+, 2005)
J/PASJ/59/335 : Properties of 160 F-K disk dwarfs/subgiants (Takeda+, 2007)
J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)
J/ApJ/735/41 : Carbon and oxygen abundances in FGK stars (Petigura+, 2011)
J/MNRAS/415/563 : Elemental abundances in Hyades supercluster (De Silva+, 2011)
J/ApJ/757/164 : Oxygen abundances of dwarf stars (Ramirez+, 2012)
J/ApJ/764/78 : Oxygen abundances in nearby FGK stars (Ramirez+, 2013)
J/A+A/594/A43 : APOGEE/Kepler sample stars abundances (Hawkins+, 2016)
J/AJ/153/21 : Abund. in local region.II. F, G, and K dwarfs (Luck+, 2017)
J/A+A/621/A112 : Carbon and oxygen in 107 dwarf stars (Pavlenko+, 2019)
J/AJ/159/90 : Li, C and O abundances of FGK stars (Stonkute+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- group Group; H=Hyades (47 occurrences), F=Field stars
(101 occurrences)
3- 8 I6 --- HIP Hipparcos catalog number (1)
10- 15 I6 --- HD HD number
17- 21 F5.2 mag Vmag Apparent visual magnitude
23- 26 F4.2 mag VMag Absolute visual magnitude
28- 31 F4.2 mag B-V B-V color (Johnson system)
33- 36 I4 K Teff effective temperature
38- 41 F4.2 [cm/s2] logg log adopted spectroscopic surface gravity
43- 47 F5.2 km/s vt Microturbulence (2)
49- 53 F5.2 [Sun] [Fe/H] Metallicity
55- 60 F6.3 [solLum] logL log bolometric luminosity
62- 65 F4.2 solMass Mass Mass (3)
67- 70 F4.2 [cm/s2] loggTLM log surface gravity (4)
72- 76 F5.2 km/s vM Macrobroadening velocity
78- 82 F5.2 [Sun] [O/H] non-LTE oxygen abundance relative to the Sun
84- 88 F5.2 [Sun] del7774 non-LTE correction for OI 7774.166
90- 94 F5.1 10-13m W7772 equivalent width for OI 7771.944 (mÅ)
96-100 F5.1 10-13m W7774 Equivalent width for OI 7774.166 (mÅ)
102-106 F5.1 10-13m W7775 Equivalent width for OI 7775.388 (mÅ)
108-112 F5.2 kpc Rm Mean galactocentric distance
114-118 F5.3 --- e Orbital eccentricity
120-124 F5.3 kpc zm Maximum separation from the galactic plane
126-130 F5.1 km/s Ulsr Space velocity in radial direction (5)
132-137 F6.1 km/s Vlsr Space velocity in tangential direction(5)
139-143 F5.1 km/s Wlsr Space velocity in vertical direction (5)
145-149 F5.1 km/s v(LSR) Speed relative to LSR (6)
151-159 F9.5 deg RAdeg Right Ascention in decimal degrees (J2000.0)
161-169 F9.5 deg DEdeg Declination in decimal degrees (J2000.0)
171-174 I4 yr Obs.Y UT year of observation
175-176 I2 "month" Obs.M UT month of observation
177-178 I2 d Obs.D UT day of observation
180-189 A10 --- Inst Obervation site/instrument (7)
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Note (1): Regarding Xi Boo B (the last line), HP number of 999999 was
tentatively assigned, because it is not included in the Hipparcos
catalogue. Besides, since "HD131156" is for the binary system as a
whole, HD number of Xi Boo B should actually be written as
"HD131156B".
Note (2): Since (unreasonable) negative vt values were obtained for
HIP057939 (-0.10) and HIP098792 (-0.18), vt=0.5km/s was assumed
in abundance derivations for these two stars.
Note (3): From logL, Teff, [Fe/H] along with theoretical tracks.
Note (4): From Teff, L, M.
Note (5): Relative to the Local Standard of Rest.
Note (6): Where v(LSR) = sqrt(Ulsr2 + Vlsr2 + Wlsr2).
Note (7): Instruments as follows:
OAO/HIDES = Okayama Astrophysical Observatory / HIgh Dispersion
Echelle Spectrograph (118 occurrences)
SUBARU/HDS = Subaru Telescope / High Dispersion Spectrograph
(30 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 16-Sep-2020