J/ApJS/258/9     Stellar population parameters from LAMOST DR7     (Wang+, 2022)
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Stellar populations of galaxies in the LAMOST spectral survey.
    Wang L.-L., Shen S.-Y., Luo A.-L., Yang G.-J., Gai N., Tang Y.-K.,
    Wang M.-X., Qin Li, Han J.-S., Rong L.-X.
   <Astrophys. J. Suppl. Ser., 258, 9 (2022)>
   =2022ApJS..258....9W
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ADC_Keywords: Spectra, optical; Surveys; Redshifts; Stars, ages; Abundances
Keywords: Galaxies ; Stellar populations ; Spectroscopy ; Catalogs

Abstract:
    We first derive the stellar population properties: age and metallicity
    for ~43000 low redshift galaxies in the DR7 of the Large Sky Area
    Multi-Object Fiber Spectroscopic Telescope (LAMOST) survey, which have
    no spectroscopic observations in the Sloan Digital Sky Survey (SDSS).
    We employ a fitting procedure based on the small-scale features of
    galaxy spectra so as to avoid possible biases from the uncertain flux
    calibration of the LAMOST spectroscopy. We show that our algorithm can
    successfully recover the average age and metallicity of the stellar
    populations of galaxies down to signal-to-noise ratio >=5 through
    testing on both mock galaxies and real galaxies comprising LAMOST and
    their SDSS counterparts. We provide a catalog of the age and
    metallicity for ~43000 LAMOST galaxies online. As a demonstration of
    the scientific application of this catalog, we present the Holmberg
    effect on both age and metallicity of a sample of galaxies in galaxy
    pairs.

File Summary:
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 FileName  Lrecl  Records  Explanations
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ReadMe        80        .  This file
table1.dat    72    42885  Catalogue of the stellar population parameters
                            for ~43000 galaxies in LAMOST DR7.
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See also:
 V/146 : LAMOST DR1 catalogs (Luo+, 2015)
 V/156 : LAMOST DR7 catalogs (Luo+, 2019)
 V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
 J/ApJS/94/687       : Old stellar populations. V. (Worthey+, 1994)
 J/A+AS/141/371      : Low-mass stars evolutionary tracks (Girardi+, 2000)
 J/AJ/127/1883       : Merging galaxies in SDSS EDR (Allam+, 2004)
 J/MNRAS/371/703     : MILES library of empirical sp. (Sanchez-Blazquez+, 2006)
 J/MNRAS/404/1639    : MILES models & new line index syst. (Vazdekis+, 2010)
 J/other/RAA/15.1414 : E+A galaxy candidates in LAMOST DR2 (Yang+, 2015)
 J/AJ/151/24         : LAMOST quasar survey: QSOs from the DR1 (Ai+, 2016)
 J/ApJS/222/16       : Herschel obs. of major-merger pairs of gal. (Cao+, 2016)
 J/other/RAA/16.C7   : LAMOST-SDSS galaxy pairs (Shen+, 2016)
 J/MNRAS/474/1873    : Classification of LAMOST DR4 galaxies (Wang+, 2018)
 J/ApJS/234/5        : LaCoSSPAr in the Southern Galactic Cap. I. (Yang+, 2018)

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  [102096/746812078] LAMOST DR7 spectral
                             observation identifier
 11- 21 F11.7  deg   RAdeg  Right Ascension, decimal degrees (J2000)
 23- 32 F10.7  deg   DEdeg  [-9/78] Declination, decimal degrees (J2000)
 34- 41 F8.6   ---   zspec  [0/0.4] spectroscopic redshift
 43- 48 F6.2   ---   SNr    [5/224] Signal-to-noise ratio in the r-band
 50- 58 F9.3   mag   rmag   [9.8/31.9]?=-9999 Petrosian magnitude in r band (1)
 60- 65 F6.3   [yr]  logAge [7.8/10.2] log of mean stellar age
 67- 72 F6.3   [Sun] [M/H]  [-1.71/0.22] lof of mean stellar metallicity, Z
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Note (1): Petrosian magnitude in r-band cross-matched with the photometric
    catalog of SDSS.
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History:
    From electronic version of the journal

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(End)                    Prepared by [AAS], Emmanuelle Perret [CDS]  28-Apr-2022
