J/MNRAS/475/3633 Mass and age of red giant branch stars (Wu+, 2018)
Mass and age of red giant branch stars observed with LAMOST and Kepler.
Wu Y., Xiang M., Bi S., Liu X., Yu J., Hon M., Sharma S., Li T., Huang Y.,
Liu K., Zhang X., Li Y., Ge Z., Tian Z., Zhang J., Zhang J.
<Mon. Not. R. Astron. Soc., 475, 3633-3643 (2018)>
=2018MNRAS.475.3633W 2018MNRAS.475.3633W (SIMBAD/NED BibCode)
ADC_Keywords: Stars, giant ; Stars, masses ; Stars, ages ; Abundances
Keywords: asteroseismology - stars: evolution - stars: fundamental parameters
Abstract:
Obtaining accurate and precise masses and ages for large numbers of
giant stars is of great importance for unraveling the assemblage
history of the Galaxy. In this paper, we estimate masses and ages of
6940 red giant branch (RGB) stars with asteroseismic parameters
deduced from Kepler photometry and stellar atmospheric parameters
derived from LAMOST spectra. The typical uncertainties of mass is a
few per cent, and that of age is ∼20 per cent. The sample stars
reveal two separate sequences in the age-[α/Fe] relation - a
high-α sequence with stars older than ∼8Gyr and a
low-α sequence composed of stars with ages ranging from younger
than 1Gyr to older than 11Gyr. We further investigate the
feasibility of deducing ages and masses directly from LAMOST spectra
with a machine learning method based on kernel based principal
component analysis, taking a sub-sample of these RGB stars as a
training data set. We demonstrate that ages thus derived achieve an
accuracy of ∼24 per cent. We also explored the feasibility of
estimating ages and masses based on the spectroscopically measured
carbon and nitrogen abundances. The results are quite satisfactory and
significantly improved compared to the previous studies.
Description:
We have estimated masses and ages for 6940 RGB stars observed by the
LAMOST-Kepler project that have accurate asteroseismic parameters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 276 3726 Deduced parameters of the 3726 uniq RGB
sample stars
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 35 A35 --- spID LAMOST spectrum identifier
37- 44 I8 --- KIC KIC number
46- 57 F12.7 K Teff Effective temperature
59- 69 F11.7 K e_Teff rms uncertainty on Teff
71- 80 F10.7 [cm/s2] logg Surface gravity
82- 90 F9.7 [cm/s2] e_logg rms uncertainty on logg
92-101 F10.7 [-] [Fe/H] Metallicity
103-111 F9.7 [-] e_[Fe/H] rms uncertainty on [Fe/H]
113-122 F10.7 [-] [alpha/Fe] Abundance [alpha/Fe]
124-132 F9.7 [-] e_[alpha/Fe] rms uncertainty on [alpha/Fe]
134-143 F10.7 [-] [C/H] Abundance [C/H]
145-153 F9.7 [-] e_[C/H] rms uncertainty on [C/H]
155-164 F10.7 [-] [N/H] Abundance [N/H]
166-174 F9.7 [-] e_[N/H] rms uncertainty on [N/H]
176-185 F10.7 uHz dnu Frequency separation of two modes of the
same spherical degree and consecutive
radial order
187-195 F9.7 uHz e_dnu rms uncertainty on dnu
197-207 F11.7 uHz numax Frequency with the maximal oscillation
power
209-217 F9.7 uHz e_numax rms uncertainty on numax
219-227 F9.7 Msun Mass Mass
229-237 F9.7 Msun e_Mass rms uncertainty on Mass
239-257 F19.16 Gyr Age Age
259-276 F18.16 Gyr e_Age rms uncertainty on Age
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 08-Apr-2021