Available Optical Spectral Data
The major spectroscopic results are contained in a few different file structures (on SAS) and database tables (in CAS), listed below. In the case of the SAS files, the large FITS files are all line-by-line matched, so that the Nth entry in any file refers to the same object. The “plates” file, listed first below, is especially useful as a full list of the plates released. Note that the links into SAS below bring you into the full directory tree; it is best not to wander there before first reading both Understanding SDSS Spectroscopic Data and the data model.
Methods for accessing these data are summarized on the data access page. Also see the spectro pipeline page for a more complete list of spectro pipeline output files and their download locations.
Spectral FITS files are also available through the SkyServer Explore tool.
SAS location | CAS table | Description |
---|---|---|
plates-dr16.fits(3.7 Mb) (in SPECTRO_REDUX; see datamodel) |
plateX | List of all DR16 plates (available as Yanny file too) |
specObj-dr16.fits (2.9 Gb) (in SPECTRO_REDUX;(see datamodel) |
specObj (only primaries) |
Redshifts and classifications of all SDSS spectra (also available in BOSS-only and SDSS-only versions) |
ssppOut-dr12.fits (1.8 Gb) (in SSPP_REDUX; see datamodel) |
sppParams | Stellar parameters from SSPP |
ssppOut-dr12.lineindex.fits (2.3 Gb) (in SSPP_REDUX; see datamodel) |
sppLines | Stellar line indices from SSPP |
photoPlate-dr16.fits (7.9 Gb) (in SPECTRO_REDUX; see datamodel) |
join on photoObj | Photometric flux-based matches |
photoPosPlate-dr16.fits (7.5 Gb) (in SPECTRO_REDUX; see datamodel) |
join on photoObj | Photometric position-based matches |
photoMatchPlate-dr16.fits (370 Mb) (in SPECTRO_REDUX; see datamodel) |
details of match results | |
galSpecInfo-dr8.fits (364 Mb) (in SPECTRO_REDUX; see datamodel) |
galSpecInfo | Information for each galaxy processed by Garching group (deprecated in DR10) |
galSpecIndx-dr8.fits (1.9 Gb) (in SPECTRO_REDUX; see datamodel) |
galSpecIndx | Index measurements for each galaxy (deprecated in DR10) |
galSpecLine-dr8.fits (1.7 Gb) (in SPECTRO_REDUX; see datamodel) |
galSpecLine | Line measurements for each galaxy (deprecated in DR10) |
galSpecExtra-dr8.fits (339 Mb) (in SPECTRO_REDUX; see datamodel) |
galSpecExtra | Extra physical parameters for each galaxy (deprecated in DR10) |
SAS location | CAS table | Description |
---|---|---|
spPlate-PLATE-MJD.fits (in SPECTRO_REDUX/[RUN2D]/[PLATE]; see datamodel) |
Coadded spectra grouped by plate | |
spec-PLATE-MJD-FIBER.fits (in BOSS_SPECTRO_REDUX/[RUN2D]/spectra/[PLATE]; see datamodel) |
Individual spectra, one file per PLATE-MJD-FIBER | |
spec-image-PLATE-MJD-FIBER.png (in SPECTRO_REDUX/images/[RUN2D]/[PLATE]) |
specObjAll | PNG images of each spectrum |