J/AJ/155/181 LAMOST/SP_Ace DR1 catalog (Boeche+, 2018)
LAMOST DR1: stellar parameters and chemical abundances with SP_Ace.
Boeche C., Smith M.C., Grebel E.K., Zhong J., Hou J.L., Chen L., Stello D.
<Astron. J. 155, 181 (2018)>
=2018AJ....155..181B 2018AJ....155..181B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Spectroscopy ; Abundances ; Stars, normal
Keywords: catalogs - stars: abundances - Galaxy: abundances - surveys
Abstract:
We present a new analysis of the LAMOST DR1 survey spectral database
performed with the code SP_Ace, which provides the derived stellar
parameters Teff, logg, [Fe/H], and [alpha/H] for 1,097,231 stellar
objects. We tested the reliability of our results by comparing them to
reference results from high spectral resolution surveys. The expected
errors can be summarized as ∼120K in Teff, ∼0.2 in logg, ∼0.15dex
in [Fe/H], and ∼0.1dex in [alpha/Fe] for spectra with S/N>40, with
some differences between dwarf and giant stars. SP_Ace provides error
estimations consistent with the discrepancies observed between derived
and reference parameters. Some systematic errors are identified and
discussed. The resulting catalog is publicly available at the LAMOST
and CDS websites.
Description:
The catalog contains stellar parameters including effective
temperature (Teff), gravity (log g), metallicity [M/H], together with
chemical abundances [Fe/H] and [alpha/H], derived with the code
SP_Ace. It consists of 2,052,662 spectra, mostly Milky Way stars, from
which 1,097,231 have measured parameters. The confidence intervals of
the stellar parameters are expressed along with their upper and lower
limits. Together with these main parameters we report other auxiliary
information such as object designation, RA, DE, and other diagnostics
as indicated in the table description.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 259 2052662 Stellar parameters and chemical abundances for
the SP_Ace-LAMOST DR1 catalog
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See also:
V/146 : LAMOST DR1 catalogs (Luo+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- ObsID Identification number of the spectrum
11- 29 A19 --- Name Object designation (JHHMMSS.ss+DDMMSS.s)
31- 41 F11.7 deg RAdeg Right ascension (J2000.0)
43- 52 F10.7 deg DEdeg Declination (J2000.0)
54- 63 A10 --- Obs.Date Date of observation (YYYY-MM-DD)
65- 69 I5 d LMJD Local modified julian day
71- 90 A20 --- PlanId Plan ID in use
92- 93 I2 --- spId Spectrograph ID
95- 97 I3 --- FiberID Fiber ID
99-104 F6.1 km/s RVb ? Radial velocity correction of the
blue part of the spectrum
106-111 F6.1 km/s RVr ? Radial velocity correction of the
red part of the spectrum
113-116 F4.1 0.1nm FWHMb ? Full-Width-Half-Maximum of the
blue part of the spectrum
118-121 F4.1 0.1nm FWHMr ? Full-Width-Half-Maximum of the
red part of the spectrum
123-127 F5.1 --- S/N ? Signal-to-Noise ratio computed by
SP_Ace
129-132 I4 K Teff ? Effective temperature
134-137 I4 K b_Teff ? Effective temperature lower limit
139-142 I4 K B_Teff ? Effective temperature upper limit
144-146 F3.1 [cm/s2] logg ? Log gravity
148-150 F3.1 [cm/s2] b_logg ? Log gravity lower limit
152-154 F3.1 [cm/s2] B_logg ? Log gravity upper limit
156-160 F5.2 [-] [M/H] ? Nominal metallicity of the
atmosphere model
162-166 F5.2 [-] b_[M/H] ? Nominal metallicity lower limit
168-172 F5.2 [-] B_[M/H] ? Nominal metallicity upper limit
174-178 F5.2 [-] [Fe/H] ? Iron abundance (1)
180-184 F5.2 [-] b_[Fe/H] ? Iron abundance lower limit
186-190 F5.2 [-] B_[Fe/H] ? Iron abundance upper limit
192-195 I4 --- o_Fe Number of iron lines measured
197-201 F5.2 [-] [a/H] ? Alpha-elements abundance (2)
203-207 F5.2 [-] b_[a/H] ? Alpha-elements abundance lower limit
209-213 F5.2 [-] B_[a/H] ? Alpha-elements abundance upper limit
215-217 I3 --- o_a Number of alpha-elements lines measured
219 I1 --- Flag Spectra flag (3)
221-227 A7 --- Class LAMOST classification of the object
229-242 F14.11 --- z ? Redshift (from the LAMOST pipeline)
244-259 F16.11 --- e_z []? Redshift error (from the LAMOST
pipeline)
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Note (1): we call "iron abundance" the abundance of all non-alpha
elements as though they were one single element (see section 3.1 of the
paper). Among these elements, iron is the main driver of this parameter due
to the preponderance of iron lines.
Note (2): the alpha-elements abundance expresses the abundance of
Mg, Si, Ca, and Ti, measured as though they were one single element
(see section 3.1 of the paper).
Note (3): the parameters of spectra with flag=0 must be rejected or treated
with extreme caution (see section 3.3 of the paper).
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Acknowledgements:
Corrado Boeche, corrado(at)ari.uni-heidelberg.de
(End) Patricia Vannier [CDS] 09-Apr-2018