J/ApJ/858/28 Mixing-length parameter for a sample of KIC stars (Viani+, 2018)
Investigating the metallicity-mixing-length relation.
Viani L.S., Basu S., J.O. J M, Bonaca A., Chaplin W.J.
<Astrophys. J., 858, 28 (2018)>
=2018ApJ...858...28V 2018ApJ...858...28V
ADC_Keywords: Abundances, [Fe/H]; Models
Keywords: stars: fundamental parameters ; stars: interiors ;
stars: oscillations (including pulsations)
Abstract:
Stellar models typically use the mixing-length approximation as a way
to implement convection in a simplified manner. While conventionally
the value of the mixing-length parameter, α, used is the
solar-calibrated value, many studies have shown that other values of
α are needed to properly model stars. This uncertainty in the
value of the mixing-length parameter is a major source of error in
stellar models and isochrones. Using asteroseismic data, we determine
the value of the mixing-length parameter required to properly model a
set of about 450 stars ranging in logg, Teff, and [Fe/H]. The
relationship between the value of α required and the properties
of the star is then investigated. For Eddington atmosphere,
non-diffusion models, we find that the value of α can be
approximated by a linear model, in the form of
α/α☉=5.426-0.101, log(g)-1.071,
log(Teff)+0.437([Fe/H]). This process is repeated using a variety of
model physics, as well as compared with previous studies and results
from 3D convective simulations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 70 453 The sample of stars in the study
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/ApJ/749/152 : Asteroseismic analysis of 22 solar-type stars (Mathur+, 2012)
J/A+A/557/A26 : STAGGER-grid of 3D stellar models. I. (Magic+, 2013)
J/ApJS/215/19 : APOKASC catalog of Kepler red giants (Pinsonneault+, 2014)
J/ApJ/808/187 : Metallicities of KIC stars without planets (Buchhave+, 2015)
J/A+A/573/A89 : STAGGER-grid of 3D stellar models. III. (Magic+, 2015)
J/MNRAS/452/2127 : Fundamental param. of Kepler stars (Silva Aguirre+, 2015)
J/A+A/601/A67 : Kepler solar-type stars modeling (Creevey+, 2017)
J/ApJ/835/172 : Kepler asteroseismic LEGACY sample. I. (Lund+, 2017)
J/ApJS/229/30 : Revised properties of Q1-17 Kepler targets (Mathur+, 2017)
J/ApJS/233/23 : APOKASC catalog of KIC dwarfs and subgiants (Serenelli+, 2017)
J/ApJ/835/173 : Kepler asteroseismic LEGACY sample. II. (Silva Aguirre+, 2017)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 I8 -- KIC [1430163/12508433] The star's KIC number
10- 17 F8.3 uHz numax [253/4190] The numax value (1)
19- 25 F7.3 uHz e_numax [3/731] Uncertainty in numax
27- 33 F7.3 uHz Dnu [17.3/173.3] The Δν value (1)
35- 39 F5.3 uHz e_Dnu [0.03/8.6] Uncertainty in Dnu
41- 44 I4 K Teff [4756/6875] Effective temperature
from Mathur+ (2017, J/ApJS/229/30)
46- 47 I2 K e_Teff [49/58] Uncertainty in Teff
49- 53 F5.2 -- [Fe/H] [-0.7/0.5] Metallicity
from Buchhave & Latham (2015, J/ApJ/808/187)
55- 58 F4.2 -- e_[Fe/H] [0.08] Uncertainty in [Fe/H]
60- 64 F5.3 -- alpha [1/2.7] Mixing length value (2)
66- 70 F5.3 -- e_alpha [0.05/1.7] Uncertainty in alpha
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Note (1): From the observed time series and power spectra of the star
(Serenelli+ 2017, J/ApJS/233/23).
Note (2): These are the likelihood weighted average values from this study
for the non-diffusion, 0.2Hp models.
Table1: Best-fit values to Equation(9) for the non-diffusion, 0.2Hp models
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Eq. (9): α/α☉=a+b.log(g)+c.log(Teff)+d([Fe/H])
a b c d
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5.426±0.752 -0.101±0.025 -1.071±0.221 0.437±0.029
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 08-Mar-2019