J/ApJS/245/34 Abundances for 6 million stars from LAMOST DR5 (Xiang+, 2019)
Abundance estimates for 16 elements in 6 million stars from LAMOST DR5
low-resolution spectra.
Xiang M., Ting Y.-S., Rix H.-W., Sandford N., Buder S., Lind K., Liu X.-W.,
Shi J.-R., Zhang H.-W.
<Astrophys. J. Suppl. Ser., 245, 34 (2019)>
=2019ApJS..245...34X 2019ApJS..245...34X
ADC_Keywords: Abundances; Spectroscopy; Radial velocities;
Stars, double and multiple
Keywords: Spectroscopy ; Spectroscopic binary stars ; Stellar atmospheres ;
Stellar abundances ; Astronomy databases ; Stellar properties ;
Stellar spectral lines ; Astronomy data analysis ; Sky surveys ;
Fundamental parameters of stars ; Milky Way Galaxy ;
Astronomy data modeling
Abstract:
We present the determination of stellar parameters and individual
elemental abundances for 6 million stars from ∼8 million
low-resolution (R∼1800) spectra from LAMOST DR5. This is based on a
modeling approach that we dub the data-driven Payne (DD-Payne), which
inherits essential ingredients from both the Payne and the Cannon. It
is a data-driven model that incorporates constraints from theoretical
spectral models to ensure the derived abundance estimates are
physically sensible. Stars in LAMOST DR5 that are in common with
either GALAH DR2 or APOGEE DR14 are used to train a model that
delivers stellar parameters (Teff, log g, Vmic) and abundances for 16
elements (C, N, O, Na, Mg, Al, Si, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, and
Ba) over a metallicity range of -4dex<[Fe/H]<0.6dex when applied to
the LAMOST spectra. Cross-validation and repeat observations suggest
that, for S/Npixel≥50, the typical internal abundance precision is
0.03-0.1dex for the majority of these elements, with 0.2-0.3dex for Cu
and Ba, and the internal precision of Teff and logg is better than 30K
and 0.07dex, respectively. Abundance systematics at the ∼0.1dex level
are present in these estimates but are inherited from the
high-resolution surveys' training labels. For some elements, GALAH
provides more robust training labels, for others, APOGEE. We provide
flags to guide the quality of the label determination and identify
binary/multiple stars in LAMOST DR5.
Description:
Stellar parameters (Teff, logg, Vt) and abundances of 16 elements (C,
N, O, Na, Mg, Al, Si, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, and Ba) are
measured from ∼8 million low-resolution (R∼1800) spectra of LAMOST DR5.
For each star, we derive two sets of stellar labels utilizing a
LAMOST-GALAH training set and a LAMOST-APOGEE training set. We
compare the two sets of labels and provide a recommended set of
results for individual labels.
The Galactic Archaeology with HERMES (GALAH; De Silva+
2015MNRAS.449.2604D 2015MNRAS.449.2604D --See Buder+, 2018 J/MNRAS/478/4513) survey is a
high-resolution (R∼28000) spectroscopic survey using the High
Efficiency and Resolution Multi-Element Spectrograph (HERMES) on the
Anglo-Australian Telescope. See Section 3.1.
Apache Point Observatory Galactic Evolution Experiment (APOGEE;
Majewski+ 2017AJ....154...94M 2017AJ....154...94M) is a high-resolution (R∼22500) infrared
(1.51-1.70um) sky survey. See Section 3.2.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
catalog.dat 984 8162566 The recommended catalog created by combining the
result from the LAMOST-GALAH and
the LAMOST-APOGEE training sets
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Description of file:
DDPayneLAMOSTDR5recommend.fits, available on the FTP section, is the
original catalog in FITS format.
See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
V/146 : LAMOST DR1 catalogs (Luo+, 2015)
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
J/A+A/503/545 : EWs of Li, Na, Fe, Ca in NGC 6397 (Lind+, 2009)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)
J/other/RAA/11.924 : Atmospheric parameters for 771 stars (Wu+, 2011)
J/AJ/146/133 : Stellar param. from SDSS-III APOGEE DR10 (Meszaros+, 2013)
J/A+A/562/A71 : Abundances of solar neighbourhood dwarfs (Bensby+, 2014)
J/AJ/148/81 : APASS BVgri photometry of RAVE stars. I. (Munari+, 2014)
J/A+A/568/A25 : C and O abundances in stellar populations (Nissen+, 2014)
J/A+A/577/A9 : Sc, V, Mn, and Co in Milky Way stars (Battistini+, 2015)
J/MNRAS/454/2863 : Teff against colours calibrations (Huang+, 2015)
J/ApJ/808/16 : Cannon: a new approach to determine abundances (Ness+, 2015)
J/MNRAS/448/822 : LAMOST candidate members of star clusters (Xiang+, 2015)
J/AJ/151/144 : ASPCAP weights for APOGEE chemical elements (Garcia+, 2016)
J/other/RAA/16.G10 : [alpha/Fe] ratios from LAMOST spectra (Li+, 2016)
J/ApJ/833/225 : -2.6≤[Fe/H]≤0.2 F & G dwarfs. II. Abundances (Zhao+, 2016)
J/ApJ/836/5 : Abundances of LAMOST giants from APOGEE DR12 (Ho+, 2017)
J/ApJS/228/24 : GALAH semi-automated classification scheme (Traven+, 2017)
J/MNRAS/478/4513 : GALAH Survey DR2 (Buder+, 2018)
J/ApJ/852/49 : Properties of metal-poor stars in APOGEE DR13 (Hayes+, 2018)
J/AJ/156/18 : APOGEE DR14: Binaries (Price-Whelan+, 2018)
J/AJ/156/45 : M-dwarf multiples in the SDSS-III/APOGEE (Skinner+, 2018)
J/AJ/156/90 : New cat. of APOGEE RVel standard stars (Huang+, 2018)
J/AJ/156/126 : Stellar param. & abund. from BACCHUS (Jonsson+, 2018)
J/AJ/158/14 : Stellar pop. of GCls using APOGEE (Nataf+, 2019)
J/AJ/158/106 : EBs RVs from APOGEE spectra (Cunningham+, 2019)
http://dr5.lamost.org/ : LAMOST DR5 home page
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 36 A36 --- SpecID LAMOST spectral ID in the format
of "date-planid-spid-fiberid"
38- 47 F10.6 deg RAdeg LAMOST DR5 Right ascension (J2000) (RA)
49- 58 F10.6 deg DEdeg [-10/63] LAMOST DR5 declination
(J2000) (DEC)
60- 69 F10.6 --- snru [0/999] Spectral S/N per pixel
in SDSS u-band
71- 80 F10.6 --- snrg [0/999] Spectral S/N per pixel
in SDSS g-band
82- 91 F10.6 --- snrr [0/999] Spectral S/N per pixel
in SDSS r-band
93-102 F10.6 --- snri [0/999] Spectral S/N per pixel
in SDSS i-band
104-113 F10.6 --- snrz [0/999] Spectral S/N per pixel
in SDSS z-band
115-126 E12.6 km/s RV [-1483/1.33e+6] Radial velocity
from LAMOST DR5
128-139 E12.6 km/s e_RV [-3e+9/3e+13]?=-9999 Uncertainty in
radial velocity (RV_ERR)
141-148 F8.2 K Teff [1000/21247]?=- Effective temperature
150-161 E12.6 K e_Teff [0.3/3.4e+8] Uncertainty in Teff (TEFF_ERR)
163 I1 --- q_Teff Quality flag for Teff (1: reliable)
(TEFF_FLAG) (1)
165-172 F8.6 --- TeffCor Correlation coefficients
(TEFF_GRADCORR) (2)
174-185 E12.6 [cm/s2] logg [/22.5]?=-999 Log of surface gravity
187-198 E12.6 [cm/s2] e_logg [0.0002/157702] Uncertainty in logg
(LOGG_ERR)
200 I1 --- q_logg Quality flag for logg (1: reliable)
(LOGG_FLAG) (1)
202-209 F8.6 --- loggCor Correlation coefficients
(LOGG_GRADCORR) (2)
211-220 F10.5 km/s Vt [-999/16.5]?=- Microturbulent velocity
(VMIC)
222-233 F12.5 km/s e_Vt [0.0004/167609] Uncertainty in Vt
(VMIC_ERR)
235 I1 --- q_Vt Quality flag for Vt (1: reliable)
(VMIC_FLAG) (1)
237-245 F9.6 --- Vtcorr [-0.15/1] Correlation coefficients
(VMIC_GRADCORR) (2)
247-256 F10.5 [-] [Fe/H] [-9/1.4]?=- Iron abundance (FEH)
258-269 F12.5 [-] e_[Fe/H] [0.0002/112974]?=999 Uncertainty in [Fe/H]
(FEH_ERR)
271 I1 --- q_[Fe/H] Quality flag for [Fe/H] (1: reliable)
(FEH_FLAG) (1)
273-280 F8.6 --- [Fe/H]Cor Correlation coefficients (FEH_GRADCORR) (2)
282-289 F8.5 [-] [a/Fe] [-2.5/2.3]? α-element-to-iron
abundance ratio (ALPHA_FE) (3)
291-301 F11.5 [-] e_[a/Fe] [0.0001/16203]?=999 Uncertainty
in [α/Fe] (ALPHAFEERR)
303-312 F10.5 [-] [C/Fe] [-8.2/6.3]?=- Carbon-to-iron abundance
ratio (C_FE)
314-324 F11.5 [-] e_[C/Fe] [0.0002/18299]?=999 Uncertainty in [C/Fe]
(CFEERR)
326 I1 --- q_[C/Fe] Quality flag for [C/Fe] (1: reliable)
(CFEFLAG) (1)
328-336 F9.6 --- [C/Fe]Cor Correlation coefficient (CFEGRADCORR) (2)
338-347 F10.5 [-] [N/Fe] [-9/11.2]?=- Nitrogen-to-iron abundance
ratio (N_FE)
349-359 F11.5 [-] e_[N/Fe] [0.0005/43855]?=999 Uncertainty in [N/Fe]
(NFEERR)
361 I1 --- q_[N/Fe] Quality flag for [N/Fe] (1: reliable)
(NFEFLAG) (1)
363-371 F9.6 --- [N/Fe]Cor Correlation coefficient (NFEGRADCORR) (2)
373-382 F10.5 [-] [O/Fe] [-9/9.7]?=- Oxygen-to-iron abundance
ratio (O_FE)
384-394 F11.5 [-] e_[O/Fe] [0.0007/33942]?=999 Uncertainty in [O/Fe]
(OFEERR)
396 I1 --- q_[O/Fe] Quality flag for [O/Fe] (1: reliable)
(OFEFLAG) (1)
398-406 F9.6 --- [O/Fe]Cor Correlation coefficient (OFEGRADCORR) (2)
408-417 F10.5 [-] [Na/Fe] [-1.2/1.3]?=- Sodium-to-iron abundance
ratio (NA_FE)
419-429 F11.5 [-] e_[Na/Fe] [0.004/57730]?=999 Uncertainty in [Na/Fe]
(NAFEERR)
431 I1 --- q_[Na/Fe] Quality flag for [Na/Fe] (1: reliable)
(NAFEFLAG) (1)
433-441 F9.6 --- [Na/Fe]Cor Correlation coefficient
(NAFEGRADCORR) (2)
443-452 F10.5 [-] [Mg/Fe] [-0.9/1.4]?=- Magnesium-to-iron abundance
ratio (MG_FE)
454-464 F11.5 [-] e_[Mg/Fe] [0.001/17932]?=999 Uncertainty in [Mg/Fe]
(MGFEERR)
466 I1 --- q_[Mg/Fe] Quality flag for [Mg/Fe] (1: reliable)
(MGFEFLAG) (1)
468-476 F9.6 --- [Mg/Fe]Cor Correlation coefficient
(MGFEGRADCORR) (2)
478-487 F10.5 [-] [Al/Fe] [-1.1/1.4]?=- Aluminium-to-iron abundance
ratio (AL_FE)
489-499 F11.5 [-] e_[Al/Fe] [0.002/29705]?=999 Uncertainty in [Al/Fe]
(ALFEERR)
501 I1 --- q_[Al/Fe] Quality flag for [Al/Fe] (1: reliable)
(ALFEFLAG) (1)
503-511 F9.6 --- [Al/Fe]Cor Correlation coefficient
(ALFEGRADCORR) (2)
513-522 F10.5 [-] [Si/Fe] [-1.7/1.3]?=- Silicon-to-iron abundance
ratio (SI_FE)
524-534 F11.5 [-] e_[Si/Fe] [0.0008/23796]?=999 Uncertainty in [Si/Fe]
(SIFEERR)
536 I1 --- q_[Si/Fe] Quality flag for [Si/Fe] (1: reliable)
(SIFEFLAG) (1)
538-546 F9.6 --- [Si/Fe]Cor Correlation coefficient
(SIFEGRADCORR) (2)
548-557 F10.5 [-] [Ca/Fe] [-9/6]?=- Calcium-to-iron abundance
ratio (CA_FE)
559-569 F11.5 [-] e_[Ca/Fe] [0.0002/34554]?=999 Uncertainty in [Ca/Fe]
(CAFEERR)
571 I1 --- q_[Ca/Fe] Quality flag for [Ca/Fe] (1: reliable)
(CAFEFLAG) (1)
573-581 F9.6 --- [Ca/Fe]Cor Correlation coefficient
(CAFEGRADCORR) (2)
583-592 F10.5 [-] [Ti/Fe] [-1.3/1.5]?=- Titanium-to-iron abundance
ratio (TI_FE)
594-604 F11.5 [-] e_[Ti/Fe] [0.0004/18596]?=999 Uncertainty in [Ti/Fe]
(TIFEERR)
606 I1 --- q_[Ti/Fe] Quality flag for [Ti/Fe] (1: reliable)
(TIFEFLAG) (1)
608-616 F9.6 --- [Ti/Fe]Cor Correlation coefficient
(TIFEGRADCORR) (2)
618-627 F10.5 [-] [Cr/Fe] [-1/0.9]?=- Chromium-to-iron abundance
ratio (CR_FE)
629-639 F11.5 [-] e_[Cr/Fe] [0.0009/22692]?=999 Uncertainty in [Cr/Fe]
(CRFEERR)
641 I1 --- q_[Cr/Fe] Quality flag for [Cr/Fe] (1: reliable)
(CRFEFLAG) (1)
643-651 F9.6 --- [Cr/Fe]Cor [-0.13/1] Correlation coefficient
(CRFEGRADCORR) (2)
653-662 F10.5 [-] [Mn/Fe] [-2.7/2]?=- Manganese-to-iron abundance
ratio (MN_FE)
664-674 F11.5 [-] e_[Mn/Fe] [0.001/27204]?=999 Uncertainty in [Mn/Fe]
(MNFEERR)
676 I1 --- q_[Mn/Fe] Quality flag for [Mn/Fe] (1: reliable)
(MNFEFLAG) (1)
678-686 F9.6 --- [Mn/Fe]Cor [-0.12/1] Correlation coefficient
(MNFEGRADCORR) (2)
688-697 F10.5 [-] [Co/Fe] [-2.8/1.8]?=- Cobalt-to-iron abundance
ratio (CO_FE)
699-709 F11.5 [-] e_[Co/Fe] [0.001/29762]?=999 Uncertainty in [Co/Fe]
(COFEERR)
711 I1 --- q_[Co/Fe] Quality flag for [Co/Fe] (1: reliable)
(COFEFLAG) (1)
713-721 F9.6 --- [Co/Fe]Cor Correlation coefficient
(COFEGRADCORR) (2)
723-732 F10.5 [-] [Ni/Fe] [-8.5/5.3]?=- Nickel-to-iron abundance
ratio (NI_FE)
734-744 F11.5 [-] e_[Ni/Fe] [0.0004/36208]?=999 Uncertainty in [Ni/Fe]
(NIFEERR)
746 I1 --- q_[Ni/Fe] Quality flag for [Ni/Fe] (1: reliable)
(NIFEFLAG) (1)
748-756 F9.6 --- [Ni/Fe]Cor Correlation coefficient
(NIFEGRADCORR) (2)
758-767 F10.5 [-] [Cu/Fe] [-9/13.5]?=- Copper-to-iron abundance
ratio (CU_FE)
769-780 F12.5 [-] e_[Cu/Fe] [0.001/150193]?=999 Uncertainty in [Cu/Fe]
(CUFEERR)
782 I1 --- q_[Cu/Fe] Quality flag for [Cu/Fe] (1: reliable)
(CUFEFLAG) (1)
784-792 F9.6 --- [Cu/Fe]Cor Correlation coefficient
(CUFEGRADCORR) (2)
794-803 F10.5 [-] [Ba/Fe] [-7.1/5.2]?=- Barium-to-iron abundance
ratio (BA_FE)
805-816 F12.5 [-] e_[Ba/Fe] [0.002/226833]?=999 Uncertainty in [Ba/Fe]
(BAFEERR)
818 I1 --- q_[Ba/Fe] Quality flag for [Ba/Fe] (1: reliable)
(BAFEFLAG) (1)
820-828 F9.6 --- [Ba/Fe]Cor Correlation coefficient
(BAFEGRADCORR) (2)
830-841 E12.6 --- Chi2 [5.1e-11/9.7e+6]? Reduced χ2 of
the spectral fit
843-854 E12.6 --- Chi2R [-13/4e+7]? χ2 excess with respect
to the typical value of stars with the
same S/N, Teff, logg, and [Fe/H]
(CHI2RATIO)
856-859 A4 --- q_Chi2 Quality flag based on "Chi2R" ("good"
or "bad") (QFLAG_CHI2)
861-872 E12.6 --- Chi2Na [0/5.2e+9] Reduced χ2 for the
NaI5891,5896Å lines computed using
the 5880-5910Å segment (CHI2_NA)
874-885 E12.6 --- Chi2RNa [-3.4/7e+8] χ2 excess for the
NaI5891,5896Å lines (CHI2RATIO_NA)
887-890 A4 --- q_Chi2Na Quality flag based on "Chi2RNa" ("good"
or "bad") (QFLAG_CHI2NA)
892-901 F10.5 --- dSNRPlx [-718/713]? Excess in spectroscopic
parallax with respect to the Gaia
astrometric parallax (SNR_DPARALLAX)
903-905 A3 --- Mult The object is a single star ("YES") or
a binary/multiple system ("NO")
(FLAG_SINGLESTAR)
907-908 I2 --- Uq [1/26] Repeat visit flag (UQFLAG) (4)
910-924 A15 --- Name Unique ID of the star (Sdddmmss+ddmmss)
(STARID)
926-935 A10 --- SubClass Stellar subclass from LAMOST DR5
(SUBCLASS) (5)
937-984 A48 --- Filename Name of the LAMOST spectral FITS file
(FILENAME)
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Note (1): Quality flag for the parameter (param) based on the examination
of the DD-Payne gradient spectra δqλ/δparam.
The flag takes the values zero and 1. Flag = 0 means that the label
estimates could be affected by astrophysical correlations; flag = 1
(reliable) otherwise.
Note (2): Correlation coefficients of δqλ/δparam between
the DD-Payne and Kurucz models.
Note (3): The [α/Fe] is defined as a weighted mean of [Mg/Fe], [Si/Fe],
[Ca/Fe], and [Ti/Fe]; see Section 5.2.
Note (4): Flag to indicate repeat visits; Uq=1 means unique star;
Uq= 2, 3, ..., n indicates the nth repeat visit
For stars with repeat visits, the "Uq" flag is sorted by the spectral
S/N, with Uq=1 having the highest S/N.
Note (5): Spectral types from O to M9 or star types: WD (6314 occurrences),
WDMagnetic (2894 occurrences), CarbonWD (362 occurrences),
CV (1666 occurrences), Carbon (2972 occurrences),
DoubleStar (2462 occurrences), EM (65 occurrences).
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History:
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(End) Emmanuelle Perret [CDS] 01-Apr-2020