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Milky Way Survey Catalog of Stellar Parameters

Milky Way Survey

Orange and green circles indicate fields with large numbers of stellar targets in sv1 and sv3, respectively, which were selected specifically for the validation of the MWS main survey and prioritized stellar targets. Black circles correspond to sv2. Gray circles show survey validation fields not associated with the stellar survey validation program. Purple points and tracks show the extent of the Sagittarius, GD 1, and Orphan streams as reported by the galstreams compilation. Gray lines indicate the approximate Galactic latitude limit of the survey, \(|b| \pm\)20\(\degree\).

Overview

This VAC release includes the results from the RVSpecfit and FERRE spectroscopic pipelines, run on the coadded spectra of objects that were either:

  • targeted by the Milky Way Survey (MWS),
  • are spectrophotometric standards,
  • classified as stars by Redrock or have low Redrock redshifts, or
  • were secondary targets.

The pipelines are described in the MWS overview paper by Cooper et al. (2023).

The RVSpecfit pipeline fits DESI spectra by interpolated PHOENIX stellar templates to obtain radial velocities and stellar parameters. The FERRE pipeline models the continuum normalised spectra to obtain stellar parameters and stellar abundances. For additional information, see Koposov et al. (in preparation).

This release includes:

  • Output of the RVSpecfit pipeline fits to likely stars in the DESI Early Data Release from coadded spectra in different healpixels on the sky (RVTAB files in rv_output/)

  • Output of the FERRE pipeline on the same set of stars (SPTAB files in sp_output/)

  • Best-fit spectral models by RVSpecfit and FERRE (RVMOD files in rv_output/ and SPMOD files in sp_output/)

  • Combined catalogs from RVSpecfit and FERRE grouped by different survey/program (rvpix-[SURVEY]-[PROGRAM].fits and sppix-[SURVEY]-[PROGRAM].fits files)

  • Combined catalog for all stars across survey/programs and with primary object indicated (mwsall-pix-fuji.fits)

The combined catalogs typically store measurements from either RVSpecfit or FERRE, but also include FITS extensions from the DESI pipeline, such as FIBERMAP and SCORES, which contain information about targeting and spectral quality. The combined catalogs also contain a separate extension with the crossmatch with Gaia DR3.

Data Access

Data URL: https://data.desi.lbl.gov/public/edr/vac/edr/mws/fuji/v1.0/

NERSC access: 

/global/cfs/cdirs/desi/public/edr/vac/edr/mws/fuji/v1.0/

Documentation

Data model

The full directory structure and data model for all products in this VAC are described here.

File contents summary (examples)

  • mwsall-pix-fuji.fits
    Combined catalog from all surveys and RVSpecfit/FERRE pipelines

  • rv_output/rvpix-sv2-dark.fits
    Combined RVspecfit measurement table for survey/program sv2/dark

  • rv_output/220309/healpix/cmx/other/21/2152/rvtab_coadd-cmx-other-2152.fits
    RVSpecfit measurements for stars in HEALPixel 2152 observed under program/survey cmx/other

  • rv_output/220309/healpix/cmx/other/21/2152/rvmod_coadd-cmx-other-2152.fits
    RVSpecfit model spectra for stars in HEALPixel 2152 observed under program/survey cmx/other

  • sp_output/sppix-sv2-backup.fits
    Combined FERRE measurement table for survey/program sv2/backup

  • sp_output/220309/healpix/sv1/backup/76/7664/sptab_coadd-sv1-backup-7664.fits
    FERRE measurements for stars in HEALPixel 7664

  • sp_output/220309/healpix/sv1/backup/76/7665/spmod_coadd-sv1-backup-7665.fits
    FERRE best-fit spectral models for stars in HEALPixel 7664

Software package versions

  • RVSpecfit: 0.2.0.220204+dev710b46
  • PIFERRE: 0.4
  • FERRE: 5.0.0

Contact

Contact Sergey Koposov or Carlos Allende with any questions.