J/MNRAS/495/2363 Asteroseismology of 36 Kepler subgiants. I. (Li+, 2020)
Asteroseismology of 36 Kepler subgiants.
I. Oscillation frequencies, linewidths, and amplitudes.
Li Y., Bedding T.R., Li T., Bi S., Stello D., Zhou Y., White T.R.
<Mon. Not. R. Astron. Soc., 495, 2363-2386 (2020)>
=2020MNRAS.495.2363L 2020MNRAS.495.2363L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, G-type ; Stars, late-type ; Asteroseismology
Keywords: stars: low-mass - stars: solar-type - stars: oscillations
Abstract:
The presence of mixed modes makes subgiants excellent targets for
asteroseismology, providing a probe for the internal structure of
stars. Here we study 36 Kepler subgiants with solar-like oscillations
and report their oscillation mode parameters. We performed a so-called
peakbagging exercise, i.e. estimating oscillation mode frequencies,
linewidths, and amplitudes with a power spectrum model, fitted in the
Bayesian framework and sampled with a Markov Chain Monte Carlo
algorithm. The uncertainties of the mode frequencies have a median
value of 0.180uHz. We obtained seismic parameters from the
peakbagging, analysed their correlation with stellar parameters, and
examined against scaling relations. The behaviour of seismic
parameters (e.g. Δν, νmax, εp) is in general
consistent with theoretical predictions. We presented the
observational p-g diagrams: γ1-Δu for early subgiants
and ΔΠ1-Δu for late subgiants, and demonstrate their
capability to estimate stellar mass. We also found a logg dependence
on the linewidths and a mass dependence on the oscillation amplitudes
and the widths of oscillation excess. This sample will be valuable
constraints for modelling stars and studying mode physics such as
excitation and damping.
Description:
We considered Kepler targets observed in a short-cadence mode, which
samples at an integration time {DELTA}t=58.89s, or frequency
fs=1/{DELTA}t=16980.8uHz.
We analyse 36 subgiants.
Table 1 lists the 36 stars in our sample along with tobs, nicknames
used in previous papers and references to any previous studies.
Mode frequencies, amplitudes, and linewidths for m = 0 modes are
presented in table 2. Table 3 presents the global oscillation
parameters. Table 4 lists the fitted parameters for all stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 61 36 Observational properties
table2.dat 61 1223 Mode parameters obtained from the peakbagging
(these are m=0 modes)
table3.dat 120 36 Global Oscillation parameters
table4.dat 110 29 Fit parameters of the Gamma - nu relation
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC Kepler ID
10- 17 A8 --- Nickname Nickname
19- 24 F6.1 d tobs ? Observation duration
26- 29 I4 K Teff ? Effective temperature
31- 35 F5.1 K e_Teff ? Uncertainty of effective temperature
37- 40 F4.2 [cm/s2] logg ? Surface gravity
42- 45 F4.2 [cm/s2] e_logg ? Uncertainty of surface gravity
47- 51 F5.2 [-] [Fe/H] ? Metallicity
53- 56 F4.2 [-] e_[Fe/H] ? Uncertainty of Metallicity
58- 61 A4 --- r_[Fe/H] References for Metallicity (1)
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Note (1): References as follows:
a = Appourchaux et al. (2012, Cat. J/A+A/543/A54)
b = Deheuvels et al. (2014A&A...564A..27D 2014A&A...564A..27D)
c = Tian et al. (2015A&A...580A..44T 2015A&A...580A..44T)
d = Appourchaux et al. (2014A&A...566A..20A 2014A&A...566A..20A)
e = Davies et al. (2016MNRAS.456.2183D 2016MNRAS.456.2183D)
f = Campante et al. (2011A&A...534A...6C 2011A&A...534A...6C)
g = Mathur et al. (2011ApJ...733...95M 2011ApJ...733...95M)
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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 I8 --- KIC Kepler ID
10 I1 --- l Angular degree
12- 18 F7.2 muHz fc Frequency centroid
20- 23 F4.2 muHz e_fc Uncertainty of frequency centroid
25- 29 F5.2 muHz lw Linewidth
31- 34 F4.2 muHz e_lw Uncertainty of linewidth
36- 40 F5.2 ppm Amp Amplitude
42- 45 F4.2 ppm e_Amp Uncertainty of amplitude
47- 54 F8.2 [-] lnK ? Bayes factor
55 A1 --- n_lnK [i] i for infinity
56- 61 F6.2 [-] e_lnK ? Uncertainty of Bayes factor
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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 Kepler ID
10- 14 F5.2 muHz Dnu Large separation (separation between adjacent
radial modes)
16- 19 F4.2 muHz e_Dnu Uncertainty of large separation
21- 25 F5.3 --- epsp Epsilon, offset of the pattern
27- 31 F5.3 --- e_epsp Uncertainty of epsilon
33- 38 F6.1 muHz numax Frequency of maximum power
40- 44 F5.1 muHz e_numax Uncertainty of frequency of maximum power
46- 50 F5.2 ppm Amax Maximum amplitude
52- 55 F4.2 ppm e_Amax Uncertainty of maximum amplitude
57- 61 F5.1 muHz Width Width of Gaussian
63- 67 F5.1 muHz e_Width Uncertainty of width of Gaussian
69- 74 F6.2 muHz dnu02 ? Small separation between 0 and 2
76- 81 F6.2 muHz e_dnu02 ? Uncertainty of small separation between 0 and 2
83- 88 F6.2 muHz dnu03 ? Small separation between 0 and 3
90- 95 F6.2 muHz e_dnu03 ? Uncertainty of small separation between 0 and 3
97-102 F6.1 muHz gamma1 ? First (n=1) g mode frequency
104-108 F5.1 muHz e_gamma1 ? Uncertainty of first (n=1) g mode frequency
110-114 F5.1 s DPi1 ? g mode period spacing, {DELTA}{PI}1
116-120 F5.1 s e_DPi1 ? Uncertainty of g mode period spacing
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC Kepler ID
10- 13 F4.2 muHz lwmax Linewidth at numax
15- 18 F4.2 muHz e_lwmax Uncertainty of linewidth at numax
20- 24 F5.2 --- alpha Power-law index
26- 29 F4.2 --- e_alpha Uncertainty of power-law index
31- 36 F6.2 muHz Gamma-alpha ? Constant
38- 43 F6.2 muHz e_Gamma-alpha ? Uncertainty of constant
45- 50 F6.2 muHz DGamma-dip ? Dip parameter amplitude
52- 57 F6.2 muHz e_DGamma-dip ? Uncertainty of dip parameter amplitude
59- 64 F6.1 muHz nu-dip ? Dip parameter frequency
66- 70 F5.1 muHz e_nu-dip ? Uncertainty of dip parameter frequency
72- 77 F6.1 muHz W-dip ? Dip parameter width
79- 84 F6.1 muHz e_W-dip ? Uncertainty of dip parameter width
86- 91 F6.1 muHz FWHM ? Dip FWHM
93- 98 F6.1 muHz e_FWHM ? Uncertainty of dip FWHM
100-104 F5.1 1/muHz A-dip ? Dip Amplitude
106-110 F5.1 1/muHz e_A-dip ? Uncertainty of dip amplitude
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Acknowledgements:
Tanda Li, tanda.li(at)sydney.edu.au
References:
Li et al., Paper II 2020MNRAS.495.3431L 2020MNRAS.495.3431L
(End) Patricia Vannier [CDS] 23-Jul-2020