J/A+A/675/A26 ∼1 million RGB and RC stars masses and ages (Wang+, 2023)
Precise masses and ages of ∼1 million RGB and RC stars observed by the LAMOST.
Wang C., Huang Y., Zhou Y., Zhang H.
<Astron. Astrophys. 675, A26 (2023)>
=2023A&A...675A..26W 2023A&A...675A..26W (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Stars, giant ; Stars, ages ; Stars, masses ; Optical
Keywords: stars: fundamental parameters
Abstract:
We construct a catalogue of stellar masses and ages for 696680 red
giant branch (RGB) stars, 180436 primary red clump (RC) stars,
and 120907 secondary RC stars selected from the LAMOSTDR8. The RGBs,
primary RCs, and secondary RCs are identified with the large frequency
spacing ({DELTA}ν) and period spacing ({DELTA}P), estimated from
the LAMOST spectra with spectral SNRs>10 by the neural network method
supervised with the seismologic information from LAMOST-Kepler sample
stars. The purity and completeness of both RGB and RC samples are
better than 95% and 90%, respectively. The mass and age of RGBs and
RCs are determined again with the neural network method by taking the
LAMOST-Kepler giant stars as the training set. The typical
uncertainties of stellar mass and age are, respectively, 10% and 30%
for the RGB stellar sample. For RCs, the typical uncertainties of
stellar mass and age are 9% and 24%, respectively. The RGB and RC
stellar samples cover a large volume of the Milky Way (5<R<20kpc and
|Z|<5 kpc), which are valuable data sets for various Galactic studies.
Description:
The catalog contains the estimates of age and mass of 696680 red giant
branch (RGB) stars, 180436 primary red clump (RC) stars, and 120907
secondary RC stars selected from LAMOST DR8.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
dr8_age.dat 178 1348645 Age and mass catalog
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See also:
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
J/A+A/588/A87 : Seismic global parameters of 6111 KIC (Vrard+, 2016)
J/ApJS/236/42 : Asteroseismology of ∼16000 Kepler red giants (Yu+, 2018)
http://www.lamost.org/dr8/v1.0 : LAMOST DR8 Home Page
Byte-by-byte Description of file: dr8_age.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- obsid Unique number ID of this spectrum in LAMOST
11- 24 F14.10 deg RAdeg Right ascension (J2000)
26- 38 F13.10 deg DEdeg Declination (J2000)
40- 49 F10.3 muHz dnu Large separation estimated adopting that
of Yu et al. (2018ApJS..236...42Y 2018ApJS..236...42Y,
Cat J/ApJS/236/42) as training data
51- 62 E12.6 muHz numax Maximum frequency
64- 75 E12.6 s dp Period spacing
77- 86 F10.3 muHz dnuv Large separation estimated adopting that of
Vrard et al. (2016A&A...588A..87V 2016A&A...588A..87V,
Cat. J/A+A/588/A87) as training data
88 I1 --- uqflag [0/1] Uniqueness flag (1)
90 A1 --- status [012] Evolutionary status (2)
92-101 F10.2 Gyr Agergb Age of RGB stars
103-116 F14.4 Msun Massrgb Mass of RGB stars
118-122 F5.3 Gyr e_Agergb Uncertainties of age of RGB stars
124-130 F7.5 Msun e_Massrgb Uncertainties of mass of RGB stars
132-143 E12.6 Gyr Agerc ?=- Age of RC stars
145-158 F14.4 Msun Massrc Mass of RC stars
160-164 F5.3 Gyr e_Agerc Uncertainties of age of RC stars
166-172 F7.5 Msun e_Massrc Uncertainties of mass of RC stars
174-178 F5.1 --- SNR The LAMOST spectral SNRs in g band
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Note (1): Uniqueness flag as follows:
1 = spectrum of the highest snr g of one star
Note (2): Evolutionary status as follows:
0 = RGB
1 = primary RC
2 = secondary RC
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Acknowledgements:
Chun Wang, wchun(at)tjnu.edu.cn
(End) Patricia Vannier [CDS] 10-May-2023