Getting all spectra and corresponding imaging data

Back to Spectra

For your convenience, there is a variant of the spectroscopic data set which has all spectra and corresponding object lists entries and atlas images. It consists of the following set of file for each plate of 640 fibers:

• spDiag-$mjd-$plate.par: the spectro1d summary
• spSpec-$mjd-$plate-$fiber.fit: the catalog of spectral lines per spectrum
• spPlate-$plate-$mjd.fits: the image of reduced spectra (1 spectrum per row)
• plPlugMapM-$plate-$mjd-$mapping.par: the mapping of targets to fibers
• spObj-$plate-$mjd-$rerun.fit: joined tsObj and spDiag and plPlugMap data for all fibers, hdu 1 = best, hdu 2 = target
• spAtlas-$plate-$mjd-$fiber.fit: best and target atlas images for all 5 colors for all fibers

The data model for a spObj-*.fit file is nearly the same as that for a tsObj file, except that a tsObj file contains all imaging information for all objects (bright and faint) in a particular 0.033 sq. deg. imaging field, while a spObj file contains all imaging information for all fibers on a particular spectroscopic plate, with an area of 7 sq. deg. spanning many imaging fields.

You can access these files, as well as catalogs of just the redshifts, in bulk at the following locations:

• The full set of plates

  • one subdirectory per plate: http://das.sdss.org/DR1/data/spectro/ss_20
    An example of what is in these directories: plate 666
  • one tar.gz file of ~85MB per plate: http://das.sdss.org/DR1/data/spectro/ss_tar_20
    We recommend to use these. Most easily retrieved using wget or rsync, with the following command:

    rsync -vtrLPR rsync://dr1@rsync.sdss.org/DR1/spectro/ss_tar_20/ ./

    The password is dr1. Also see our rsync help page.

• Just the redshifts

  There are 4 catalogs by spectroscopic classification:
  • Classified as galaxies: gals-dr1.fit.gz, 276M
  • Classified as quasars: qsos-dr1.fit.gz, 37M
    Note that the vetted DR1 quasar catalog presented by Schneider et al. 2003 is now available. The information contained in that catalog supersedes the information contained in all other DR1 data sources. We strongly recommend using that catalog instead of the list given here.
  • Classified as stars: stars-dr1.fit.gz, 44M
  • No classification possible, and sky fibers: unks-dr1.fit.gz, 15M
  There are 3 catalogs with those spectra targeted as part of one of the tiled samples:
  • Spectroscopic galaxies targeted as main galaxies: main_gals-dr1.fit.gz, 229M
  • Spectroscopic galaxies targeted as Luminous Red Galaxies (LRGs): main_lrgs-dr1.fit.gz, 27M
  • Spectroscopic quasars targeted as main survey quasars: main_qsos-dr1.fit.gz, 23M

• What about objects not observed due to fiber collisions?

  You will want the tiling information.