J/ApJS/271/26    Stellar loci. VII. FGK stars from GALEX and Gaia    (Lu+, 2024)
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Stellar loci.
VII. Photometric metallicities of 5 million FGK stars based on GALEX GR6+7 AIS
and Gaia EDR3.
    Lu X., Yuan H., Xu S., Zhang R., Xiao K., Huang Y., Beers T.C., Hong J.
   <Astrophys. J. Suppl. Ser., 271, 26 (2024)>
   =2024ApJS..271...26L
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ADC_Keywords: Stars, dwarfs; Stars, giant; Parallaxes, trigonometric;
              Proper motions; Photometry, UBV; Magnitudes, absolute; Colors;
              Surveys; Radial velocities; Abundances, [Fe/H]; Ultraviolet
Keywords: Fundamental parameters of stars ; Galaxy stellar content ;
          Astronomy data analysis ; Metallicity ; Near ultraviolet astronomy

Abstract:
    We combine photometric data from GALEX GR6+7 All-Sky Imaging Survey
    and Gaia Early Data Release 3 with stellar parameters from the SAGA
    and PASTEL catalogs to construct high-quality training samples for
    dwarfs (0.4<BP-RP<1.6) and giants (0.6<BP-RP<1.6). We apply careful
    reddening corrections using empirical temperature- and
    extinction-dependent extinction coefficients. Using the two samples,
    we establish a relationship between stellar loci (near-ultraviolet
    (NUV)-BP versus BP-RP colors), metallicity, and MG. For a given BP-RP
    color, a 1dex change in [Fe/H] corresponds to an approximately 1mag
    change in NUV-BP color for solar-type stars. These relationships are
    employed to estimate metallicities based on NUV-BP, BP-RP, and MG.
    Thanks to the strong metallicity dependence in the GALEX NUV band, our
    models enable a typical photometric-metallicity precision of
    approximately {sigma}[Fe/H]=0.11dex for dwarfs and
    {sigma}[Fe/H]=0.17dex for giants, with an effective metallicity range
    extending down to [Fe/H]=-3.0 for dwarfs and [Fe/H]=-4.0 for giants.
    We also find that the NUV-band-based photometric-metallicity estimate
    is not as strongly affected by carbon enhancement as previous
    photometric techniques. With the GALEX and Gaia data, we have
    estimated metallicities for about 5 million stars across almost the
    entire sky, including approximately 4.5 million dwarfs and 0.5 million
    giants. This work demonstrates the potential of the NUV band for
    estimating photometric metallicities, and sets the groundwork for
    utilizing the NUV data from space telescopes such as the upcoming
    Chinese Space Station Telescope.

Description:
    GALEX, launched on 2003 April 28, simultaneously performs sky surveys
    in two bands through the use of a dichroic beam splitter:
    FUV (1344-1786{AA}) and NUV (1771-2831{AA}). The field of view of
    GALEX is 1.28{deg}/1.24{deg}, with a spatial resolution of 4.2"/5.3"
    for the FUV/NUV, respectively. The GALEX GR6+7 All-Sky Imaging Survey
    (AIS) database (Bianchi+ 2017, II/335) is a valuable catalog derived
    from the mission, containing 214,449,551 source measurements. The
    photometric precision of the NUV band varies from 0.0025 to 0.5mag.

    We obtain spectroscopic data for the training samples by combining
    metallicity information from the Stellar Abundances for the Galactic
    Archeology (SAGA) and the PASTEL catalogs. See Section 2.3.

File Summary:
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 FileName    Lrecl   Records   Explanations
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ReadMe          80         .   This file
catalog.dat    327   4971805   The final sample catalog
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See also:
 B/pastel : The PASTEL catalogue (Soubiran+, 2016-)
 V/147    : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
 II/335   : Revised cat. of GALEX UV sources (GUVcat_AIS GR6+7) (Bianchi+ 2017)
 V/156    : LAMOST DR7 catalogs (Luo+, 2019)
 I/350    : Gaia EDR3 (Gaia Collaboration, 2020)
 V/154    : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
 I/352    : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
 III/286  : APOGEE-2 DR17 final allStar catalog (Abdurro'uf+, 2022)
 I/355    : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
 J/AJ/137/4377    : List of SEGUE plate pairs (Yanny+, 2009)
 J/MNRAS/412/843  : SAGA extremely metal-poor stars (Suda+, 2011)
 J/ApJ/833/20     : Carbon-enhanced metal-poor (CEMP) star abund. (Yoon+, 2016)
 J/MNRAS/478/4513 : GALAH Survey DR2 (Buder+, 2018)
 J/A+A/618/A93    : Gaia DR2 open clusters in the MW (Cantat-Gaudin+, 2018)
 J/ApJS/238/16    : LAMOST-DR3 very metal-poor star catalog (Li+, 2018)
 J/MNRAS/506/150  : The GALAH+ Survey DR3 (Buder+, 2021)
 J/ApJS/262/8     : Sp. data of low-metallicity S-PLUS stars (Placco+, 2022)
 J/A+A/666/A121   : Cluster target Giraffe HR15N RV precision (Randich+, 2022)
 J/ApJS/259/60    : SEGUE-2 updated stellar parameter pipeline (Rockosi+, 2022)
 J/A+A/659/A181   : J-PLUS DR1 stellar param, and abundances (Yang+, 2022)

Byte-by-byte Description of file: catalog.dat
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   Bytes Format Units      Label         Explanations
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  1-  19 I19    ---        GaiaEDR3      Gaia EDR3 identifier (source_id)
 21-  35 F15.11 deg        RAdeg         Gaia EDR3 right ascension
                                          (ICRS) at Ep=2016.0 (ra)
 37-  51 F15.11 deg        DEdeg         Gaia EDR3 declination
                                          (ICRS) at Ep=2016.0 (dec)
 53-  60 F8.5   mas        plx           [1e-5/79] Gaia EDR3 parallax (parallax)
 62-  68 F7.5   mas      e_plx           [0.007/1.1] plx uncertainty
                                          (parallax_error)
 70-  77 F8.5   mas        plx-cor       [0.02/79]? Parallax corrected by
                                          Lindegren+ 2021A&A...649A...4L
                                          (parallax_corrected)
 79-  86 F8.3   mas.yr-1   pmRA          [-457/379] Gaia EDR3 proper motion in
                                          RA (pmra)
 88-  93 F6.4   mas.yr-1 e_pmRA          [0.004/1] pmRA uncertainty (pmra_error)
 95- 102 F8.3   mas.yr-1   pmDE          [-442/377] Gaia EDR3 proper motion in
                                          DEC (pmdec)
104- 109 F6.4   mas.yr-1 e_pmDE          [0.005/1] pmDE uncertainty
                                          (pmdec_error)
111- 116 F6.3   ---        ruwe          [0.59/74] Renormalized unit weight
                                          error from Gaia EDR3 (ruwe)
118- 122 F5.3   ---        E(Bp-Rp)      [1.17/1.33] BP/RP excess factor from
                                          Gaia EDR3 (phot_bp_rp_excess_factor)
124- 131 F8.5   mag        Bpmag         [6.5/16.7] Integrated Bp band mean
                                          magnitude from Gaia EDR3
                                          (phot_bp_mean_mag)
133- 140 F8.5   mag        Rpmag         [5/15.7] Integrated Rp band mean
                                          magnitude from Gaia EDR3
                                          (phot_rp_mean_mag)
142- 149 F8.5   mag        Gmag          [6/16] Gaia EDR3 G-band mean magnitude
                                          (phot_g_mean_mag)
151- 165 F15.11 deg        GLON          Gaia EDR3 Galactic longitude (l)
167- 181 F15.11 deg        GLAT          Gaia EDR3 Galactic latitude (b)
183- 188 F6.3   ---        feh-Gaia      [-3.8/1]? Photometric metallicity from
                                          Xu+ 2022ApJS..258...44X (feh_gaia)
190- 195 F6.3   ---      e_feh-Gaia      [0.03/15]? feh-Gaia formal error
                                          (feh_gaia_error)
197- 204 F8.6   ---        EBV           [0.0006/0.5] Value of E(B-V)_SFD_ (ebv)
206- 208 F3.1   ---        Type          [0/1]? Source type (1=giant) (type) (1)
210- 216 F7.4   mag        NUVmag        [15/22.1] GALEX NUV calibrated
                                          magnitude in AB system (NUVmag)
218- 223 F6.4   mag      e_NUVmag        [0.003/0.2] Uncertainty on NUVmag
                                          (e_NUVmag)
225- 232 F8.6   mag        BP-RP0        [0.49/1.51] Intrinsic BP-RP color
                                          after color correction (BP_RP0)
234- 242 F9.6   mag        NUV-BP0       [-0.31/10.8] Intrinsic NUV-BP color
                                          after color correction (NUV_BP0)
244- 249 F6.3   ---        feh-GALEXold  [-5/1] Photometric metallicity derived
                                          from the previous model without
                                          consideration of M_G_ (feh_GALEX_old)
251- 256 F6.3   ---        feh-GALEX     [-4.5/1] Photometric metallicity
                                          derived from the new model with
                                          consideration of M_G_ (feh_GALEX)
258- 266 F9.6   mag        GMag          [-7.9/14]? Absolute G-band magnitude
                                          (M_G) (2)
     268 I1     ---        Flag          [0/1]? Quality flag (0=reliable)
                                          (flag) (3)
270- 278 F9.3   pc         rpgeo         [12.7/24854] Median of the
                                          photogeometric distance posterior
                                          (r_med_photogeo) from
                                          Bailer-Jones+ 2021, I/352 (rpgeo)
280- 288 F9.3   pc       b_rpgeo         [12.7/18555] 16th percentile of the
                                          photogeometric distance posterior
                                          (r_lo_photogeo) from
                                          Bailer-Jones+ 2021, I/352 
290- 298 F9.3   pc       B_rpgeo         [12.7/33862] 84th percentile of the
                                          photogeometric distance posterior
                                          (r_up_photogeo) from
                                          Bailer-Jones+ 2021, I/352 
300- 307 F8.2   km.s-1     RV            [-755/801]? Radial velocity (rv)
309- 316 F8.2   km.s-1   e_RV            [0/9999]? RV uncertainty (e_rv)
318- 327 A10    ---      r_RV            Flag on RV (flag_rv) (4)
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Note (1): Flag to classify stars (Xu+ 2022ApJS..258...44X) as follows:
    0.0 = dwarfs
    1.0 = giant (513,777 sources)
Note (2): Absolute magnitude of the G band, calculated by

    M_G_=G-10-5*log(1/plx-cor)-R_G_*E(B-V)
Note (3): Quality flag as follows:
    1 = stars outside the limits where we consider the feh-GALEX values
         to be reliable (3727 occurrences)
    0 = the stars are within the limits, and considered reliable
Note (4): Flag to indicate the source of radial velocity, which takes the
    values GALAH (DR3+), APOGEE (DR17), Gaia (DR3), LAMOST_MRS (DR9),
    LAMOST_LRS (DR9), SEGUE (DR16).
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History:
    FITS file downloaded from: http://nadc.china-vo.org/res/r101366/

References:
    Yuan et al.    Paper I.     2015ApJ...799..134Y
    Yuan et al.    Paper II.    2015ApJ...799..135Y
    Yuan et al.    Paper III.   2015ApJ...803...13Y
    Zhang et al.   Paper IV.    2021RAA....21..319Z
    Xu et al.      Paper V.     2022ApJS..258...44X
    Xu et al.      Paper VI.    2022ApJS..263...29X
    Lu et al.      Paper VII.   2024ApJS..271...26L   This catalog

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(End)                                       Emmanuelle Perret [CDS]  29-Apr-2024