J/ApJS/273/19 Elemental abundances from DESI EDR spectra (Zhang+, 2024)
Determining stellar elemental abundances from DESI spectra with the data-driven
Payne.
Zhang M., Xiang M., Ting Y.-S., Wang J., Li H., Zou Hu, Nie J., Mou L.,
Wu T., Wu Y., Liu J.
<Astrophys. J. Suppl. Ser., 273, 19 (2024)>
=2024ApJS..273...19Z 2024ApJS..273...19Z
ADC_Keywords: Spectra, optical; Abundances; Surveys; Milky Way; Space velocities
Keywords: Surveys ; Stellar abundances ; Chemical abundances ; Stellar physics ;
Stellar distance ; Spectroscopy ; Milky Way evolution
Abstract:
Stellar abundances for a large number of stars provide key information
for the study of Galactic formation history. Large spectroscopic
surveys such as the Dark Energy Spectroscopic Instrument (DESI) and
LAMOST take median-to-low-resolution (R≲5000) spectra in the full
optical wavelength range for millions of stars. However, the
line-blending effect in these spectra causes great challenges for
elemental abundance determination. Here we employ DD-Payne, a
data-driven method regularized by differential spectra from stellar
physical models, to the DESI early data release spectra for stellar
abundance determination. Our implementation delivers 15 labels,
including effective temperature Teff, surface gravity logg,
microturbulence velocity vmic, and the abundances for 12 individual
elements, namely C, N, O, Mg, Al, Si, Ca, Ti, Cr, Mn, Fe, and Ni.
Given a spectral signal-to-noise ratio of 100 per pixel, the internal
precisions of the label estimates are about 20K for Teff, 0.05dex for
logg, and 0.05dex for most elemental abundances. These results agree
with the theoretical limits from the Cramer-Rao bound calculation
within a factor of 2. The majority of the accreted halo stars
contributed by the Gaia-Enceladus-Sausage are discernible from the
disk and in situ halo populations in the resultant [Mg/Fe]-[Fe/H] and
[Al/Fe]-[Fe/H] abundance spaces. We also provide distance and orbital
parameters for the sample stars, which spread over a distance out to
∼100kpc. The DESI sample has a significantly higher fraction of
distant (or metal- poor) stars than the other existing spectroscopic
surveys, making it a powerful data set for studying the Galactic
outskirts.
Description:
Here, we apply data-driven Payne (DD-Payne) to the early data release
(EDR) of DESI (DESI Col. 2024AJ....168...58D 2024AJ....168...58D). The DESI spectra cover
the full optical range of 3600-9824Å at a FWHM resolution of about
1.8Å. The DESI collaboration has developed three pipelines for
processing the Milky Way Survey (MWS) data, including the RVS, SP, and
WD pipelines (Cooper+ 2023ApJ...947...37C 2023ApJ...947...37C).
The DESI EDR includes spectra from all the commissioning and Survey
Validation campaigns that were taken between 2020-Dec and 2021-May.
In this work, we use the data from the MWS program. In total, there
are 625588 spectra for 601782 objects with unique target IDs.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
catalog.dat 783 520228 Catalog of atmospheric parameters and elemental
abundances for stars in the early data release
of the DESI spectroscopic survey
(from erratum published in 2024, ApJS, 274, 21)
--------------------------------------------------------------------------------
Description of file:
DESIEDRDDPAYNE.fits is the original FITS file as downloaded at:
http://nadc.china-vo.org/res/r101471/
See also:
VII/233 : 2MASS All-Sky Extended Source Catalog (XSC) (IPAC/UMass, 2003-2006)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
III/286 : APOGEE-2 DR17 final allStar catalog (Abdurro'uf+, 2022)
VII/292 : DESI Legacy Imaging Surveys DR8 photometric redshifts (Duncan, 2022)
J/A+A/497/497 : Physical param. from JHK flux (Gonzalez-Hernandez+, 2009)
J/ApJ/808/16 : Cannon: a new approach to determine abundances (Ness+, 2015)
J/ApJ/836/5 : Abundances of LAMOST giants from APOGEE DR12 (Ho+, 2017)
J/ApJS/245/34 : Abund. for 6 million stars from LAMOST DR5 (Xiang+, 2019)
J/MNRAS/493/5195 : Milky Way halo stars ages and kinematics (Das+, 2020)
J/ApJ/891/23 : Stellar abundances from LAMOST MRS (SPCAnet) (Wang+, 2020)
J/ApJS/246/9 : Stellar parameters of LAMOST stars using SLAM (Zhang+, 2020)
J/other/NatAs/5.640 : Chronologically dating early assembly (Montalban+, 2021)
J/A+A/649/A3 : Gaia EDR3 photometric passbands (Riello+, 2021)
J/ApJS/253/22 : Ks abs. magnitudes from LAMOST for OB stars (Xiang+, 2021)
J/MNRAS/513/1557 : Accreted halo stars abundances (Carrillo+, 2022)
J/ApJ/931/147 : Very metal-poor stars with LAMOST & Subaru. II. (Li+, 2022)
J/A+A/666/A121 : Cluster target Giraffe HR15N RV precision (Randich+, 2022)
J/other/Nat/603.599 : 247014 subgiant stars data (Xiang+, 2022)
J/A+A/662/A66 : Hot stars from LAMOST DR6 (Xiang+, 2022)
J/ApJS/267/18 : Abundance measurements in M15 RGB stars (Sandford+, 2023)
http://www.legacysurvey.org/ : DESI Legacy Imaging Surveys homepage
http://data.desi.lbl.gov/doc/ : DESI data homepage
Byte-by-byte Description of file: catalog.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.7 deg RAdeg Target right ascension (J2000)
(TARGET_RA)
13- 23 F11.7 deg DEdeg [-31.6/85] Target declination (J2000)
(TARGET_DEC)
25- 43 I19 --- ID DESI target identifier (TARGET_ID)
45- 51 A7 --- Survey Name of the DESI survey (SURVEY)
53- 58 A6 --- Prog Name of the program (PROGRAM)
60 A1 --- Prim [FT] Primary, false or true (PRIMARY)
62- 66 I5 --- Hpix [683/45007] Healpix ID (HEALPIX)
68- 74 F7.3 --- snrB [-6.3/473.2] Median spectral
signal-to-noise ratio in B-band (SNRB)
76- 82 F7.3 --- snrG [-0.3/608] Median spectral
signal-to-noise ratio in G-band (SNRG)
84- 90 F7.3 --- snrR [0.2/771] Median spectral
signal-to-noise ratio in R-band (SNRR)
92- 101 F10.4 km/s RV [-1500/1500] Radial velocity from DESI
EDR catalog (RV)
103- 111 F9.4 km/s e_RV [0.0001/2341] RV uncertainty (RV_ERR)
113- 119 F7.2 K Teff [2642/8863]? Effective temperature
(TEFF)
121- 127 F7.2 K e_Teff [2.7/1220]? Teff uncertainty (TEFF_ERR)
129- 136 F8.3 [cm/s2] logg [-1.5/7.2]? Log of surface gravity
(LOGG)
138- 142 F5.3 [cm/s2] e_logg [0.01/3.1]? logg uncertainty (LOGG_ERR)
144- 151 F8.3 [-] [Fe/H] [-5.2/1.7]? Iron abundance (FEH)
153- 157 F5.3 [-] e_[Fe/H] [0.007/1.4]? [Fe/H] Uncertainty
(FEH_ERR)
159- 166 F8.3 [-] [C/Fe] [-1.4/2.1]? Log of C/Fe abundance
(C_FE)
168- 172 F5.3 [-] e_[C/Fe] [0.004/1.8]? [C/Fe] Uncertainty
(CFEERR)
174- 181 F8.3 [-] [N/Fe] [-1.9/2.2]? Log of N/Fe abundance
(N_FE)
183- 187 F5.3 [-] e_[N/Fe] [0.009/3]? [N/Fe] Uncertainty
(NFEERR)
189- 196 F8.3 [-] [Mg/Fe] [-0.8/1.4]? Log of Mg/Fe abundance
(MG_FE)
198- 202 F5.3 [-] e_[Mg/Fe] [0.005/3]? [Mg/Fe] Uncertainty
(MGFEERR)
204- 211 F8.3 [-] [O/Fe] [-0.8/1.6]? Log of O/Fe abundance
(O_FE)
213- 217 F5.3 [-] e_[O/Fe] [0.006/2]? [O/Fe] Uncertainty
(OFEERR)
219- 226 F8.3 [-] [Al/Fe] [-1.3/1.5]? Log of Al/Fe abundance
(AL_FE)
228- 232 F5.3 [-] e_[Al/Fe] [0.01/2.5]? [Al/Fe] Uncertainty
(ALFEERR)
234- 241 F8.3 [-] [Si/Fe] [-0.9/1.4]? Log of Si/Fe abundance
(SI_FE)
243- 247 F5.3 [-] e_[Si/Fe] [0.007/2.1]? [Si/Fe] Uncertainty
(SIFEERR)
249- 256 F8.3 [-] [Ca/Fe] [-0.9/1.4]? Log of Ca/Fe abundance
(CA_FE)
258- 262 F5.3 [-] e_[Ca/Fe] [0.006/2]? [Ca/Fe] Uncertainty
(CAFEERR)
264- 271 F8.3 [-] [Ti/Fe] [-1.2/1.5]? Log of Ti/Fe abundance
(TI_FE)
273- 277 F5.3 [-] e_[Ti/Fe] [0.006/1.5]? [Ti/Fe] Uncertainty
(TIFEERR)
279- 286 F8.3 [-] [Cr/Fe] [-1.9/1]? Log of Cr/Fe abundance
(CR_FE)
288- 292 F5.3 [-] e_[Cr/Fe] [0.009/3.6]? [Cr/Fe] Uncertainty
(CRFEERR)
294- 301 F8.3 [-] [Mn/Fe] [-1.4/0.9]? Log of Mn/Fe abundance
(MN_FE)
303- 307 F5.3 [-] e_[Mn/Fe] [0.008/3.2]? [Mn/Fe] Uncertainty
(MNFEERR)
309- 316 F8.3 [-] [Ni/Fe] [-0.9/1.1]? Log of Ni/Fe abundance
(NI_FE)
318- 322 F5.3 [-] e_[Ni/Fe] [0.008/3.1]? [Ni/Fe] Uncertainty
(NIFEERR)
324- 331 F8.3 km/s Vmic [-0.63/3.13]? Microturbulent velocity
(VMIC)
333- 337 F5.3 km/s e_Vmic [0.009/3.4]? Vmic uncertainty
(VMIC_ERR)
339- 347 F9.6 --- CorTeff-logg [-1/0.87] The correlation coefficients
between Teff and logg (CORTEFFLOGG)
349- 357 F9.6 --- CorTeff-feh [-1/0.81] The correlation coefficients
between Teff and [Fe/H] (CORTEFFFEH)
359- 367 F9.6 --- Corlogg-feh [-1/0.72] The correlation coefficients
between logg and [Fe/H] (CORLOGGFEH)
369- 379 E11.4 --- q_Chi2 [-3.2/3.9e+6]? A quality flag
describing the χ2 of the
spectral fit (CHISQ_FLAG)
381- 390 E10.4 --- Chi2 [0.009/773000]? The χ2 of the
spectral fit (CHISQ)
392- 402 E11.4 [pc] logDist [-8.1/12.7]? Log of distance (LOGDIS)
404- 414 E11.4 [pc] e_logDist [0.0002/15]? logDist uncertainty
(LOGDIS_ERR)
416- 425 E10.3 mag EBV [-0.3/0.83]? Interstellar reddening
(EBV)
427- 436 E10.3 mag e_EBV [0/3]? EBV uncertainty (EBV_ERR)
438- 448 E11.4 kpc X 3D X position in the Galactic
Cartesian coordinates (X)
450- 460 E11.4 kpc Y 3D Y position in the Galactic
Cartesian coordinates (Y)
462- 472 E11.4 kpc Z 3D Z position in the Galactic
Cartesian coordinates (Z)
474- 485 E12.6 kpc R ?=-9999 Radial position in the Galactic
cylindrical coordinates (R)
487- 498 E12.6 kpc PHI [-3.04/3.1]? Azimuthal position in the
Galactic cylindrical coordinates (PHI)
500- 511 E12.6 km/s VX [-2.2e+6/1.5e+6]?=-9999 3D velocity, X
component, in the Galactic Cartesian
coordinates (VX)
513- 524 E12.6 km/s VY [-2.2e+6/1.3e+6]?=-9999 3D velocity, Y
component, in the Galactic Cartesian
coordinates (VY)
526- 537 E12.6 km/s VZ [-2.2e+06/2e+06]?=-9999 3D velocity, Z
component, in the Galactic Cartesian
coordinates (VZ)
539- 550 E12.6 km/s VR [-2.2e+06/2.1e+06]?=-9999 Radial
velocity in the Galactic cylindrical
coordinates (VR)
552- 563 E12.6 km/s VT [-2.2e+06/2.1e+06]?=-9999 Azimuthal
velocity in the Galactic cylindrical
coordinates (VT)
565- 576 E12.6 kpc.km/s JR [-2.2e+06/26489]?=-9999 Actions in R
direction (JR)
578- 589 E12.6 kpc.km/s JPHI ?=-9999 Actions in PHI direction (JPHI)
591- 602 E12.6 kpc.km/s JZ ?=-9999 Actions in Z direction (JZ)
604- 615 E12.6 kpc.km/s LX ?=-9999 Angular momentum in the X
direction (LX)
617- 628 E12.6 kpc.km/s LY ?=-9999 Angular momentum in the Y
direction (LY)
630- 641 E12.6 kpc.km/s LZ [-2.2e+06/2.2e+06]?=-9999 Angular
momentum in the Z direction (LZ)
643- 654 E12.6 kpc RadGuid [-2.2e+06/2.2e+06]?=-9999 Guiding
center radius (R_GUIDING)
656- 667 E12.6 kpc Rapo [-2.2e+06/2.2e+06]?=-9999 Apocenter
radius (R_APO)
669- 680 E12.6 kpc Rperi [-2.2e+06/2e+06]?=-9999 Pericenter
radius (R_PERI)
682- 692 E11.4 --- Ecc [0.001/1]? Eccentricity (ECC)
694- 705 E12.6 kpc Zmax [-2.2e+06/2.2e+06]?=-9999 Maximum height
of orbits (ZMAX)
707- 718 E12.6 --- Energy [-2.2e+07/2.1e+07]?=-9999 Total energy
(ENERGY)
720- 731 E12.6 --- omegaPHI [-2.1/9999.99]? Frequency in the PHI
direction (OMEGA_PHI)
733- 744 E12.6 --- omegaR [0.017/9999.99]? Frequency in the R
direction (OMEGA_R)
746- 757 E12.6 --- omegaZ [0.01/9999.99]? Frequency in the Z
direction (OMEGA_Z)
759- 770 E12.6 --- ER [-2.2e+6/2.2e+6]?=-9999 Radial energy
772- 783 E12.6 --- EZ [-2.2e+6/2.2e+6]?=-9999 Vertical energy
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History:
Downloaded from: http://nadc.china-vo.org/res/r101471/
(DOI: 10.12149/101456)
(End) Emmanuelle Perret [CDS] 31-Dec-2024