Spectroscopic data

SDSS-III will release full spectra and spectroscopic parameters from all the plates observed by the SDSS spectrograph in DR8. These pages describe the nature of the DR8 spectroscopic data and how to use it. In particular:

Basics describes the general nature of the spectroscopic data (plates, MJDs, etc).
Pipeline describes the steps in the spectroscopic data processing and the associated files.
Data Access describes how to get the data from SAS or CAS.
Target flags describes the target classifications and how to track them in the data
Spectra describes using and analyzing the spectra
Catalogs describes the basic catalog parameters like redshifts and classifications.
Galaxies describes some extra parameters calculated for galaxy spectra in the data set.
Stars (SSPP) describes the SEGUE-2 Stellar Parameters Pipeline.
SEGUE SQL cookbook describes getting stellar parameters out of the SQL database, with examples.
Caveats describes some important caveats in using this data

The table below gives a breakdown of the numbers of plates of various sorts included in the DR8 release. The spectroscopy was executed through several programs: SDSS Legacy, SDSS special programs, SEGUE-1, and SEGUE-2. The page on spectroscopic basics explains how we track the nature of the plates (its survey and program).

Survey	Program	N_plate	N_ok	N_primary
all	all	2880	2764	2654
sdss	all	2227	2126	2043
sdss	legacy	1926	1869	1794
segue1	all	442	427	407
segue2	all	211	211	204

Please pay attention to the notes included here about how to check data quality and the various caveats on the data.