dick Data products: Value-added catalogs - SDSS DR7
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Value-Added Catalogs

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Jump to catalogs associated with:
Galaxies Quasars Groups and Clusters Stripe 82
Stars Solar System Other Alphabetical List


  • Line index measures for Galaxies: The Oh, K., Sarzi, M., Schawinski, K, and Yi, S. K. 2011 ApJS 195, 13 Spectral line strength measurement database by the OSSY group contains the values of spectral line measurements (stellar absorption line strengths, nebular emission line fluxes, quality-assessment parameters, velocity dispersions, line widths, sky-line contamination flag etc.). The archived value added tables may be downloaded from here by clicking and saving: A: Absorption line meaurements B: Emission line measurements and velocity dispersions and C: Fitting quality assessments The contents of the data tables are described in the paper. The best fitting continuum files are also available upon request to the authors. User manuals and updates are available from the OSSY group website [gem.yonsei.ac.kr].
  • Photometric Redshift 2 catalog, with probability distributions: contains links to a text version of the photoz2 table of the CAS, with additional columns representing the probability distribution function (PDF) for each object with a photometric redshift. The PDF for each object consists of values between 0 and 1 in 100 redshift bins which run from 0.03 to 1.47 where dz = 1.44/99. The PDF information is only available as a value-added catalog, whereas the photometric redshift catalog is available in the CAS for SQL searches (joined to the main galaxy database). The catalog was developed by Huan Lin of Fermilab, Carlos Cunha of the University of Michigan and collaborators at the University of Chicago: Cunha et al. (2009). The README file contains column descriptions.
  • NYU Value-Added Galaxy Catalog: a cross-matched collection of galaxy catalogs, including the SDSS, maintained for the study of galaxy formation and evolution. It includes carefully constructed large-scale structure samples useful for calculating power spectra, etc, and includes, e.g., the "LSS Sample12" described in various Blanton et al. and Tegmark et al. SDSS papers.
  • CMU-PITT SDSS Value Added Catalog (VAC): a database that allows users to conduct scientific analyses on the SDSS spectroscopic galaxy data. It allows for easy use of spectral information (i.e. emission line-widths), and for anybody to upload Science Derivatives for SDSS galaxies. (DR3 catalog)
  • MPA/JHU value-added galaxy catalog: contains results from a custom galaxy spectral fitting code (line fluxes, continuum indices, line widths, EWs etc.) mostly written by Christy Tremonti and described in Tremonti et al (2004). The following derived data are also available:
  • The 2SLAQ LRG Catalog: As described in Cannon et al. 2006 (MNRAS, 372, 425 (2006)), this is a spectroscopic survey of nearly 15,000 intermediate-redshift luminous red galaxies (LRGs) brighter than i=19.8, selected from SDSS photometry and observed with the 2dF spectrograph on the AAT to probe higher redshift and lower luminosity galaxies than the SDSS LRG sample, over an area of 180 deg2.


Groups and Clusters

Stripe 82


Solar System


  • The Princeton spectra are the newer of two parallel codes to determine spectroscopic classification and redshift; they are also known as SpecBS. The determination of redshifts and classifications direct chi-squared fitting of templates to spectra. These reductions are included in DR7, with documentation available at the Princeton Spectra site.
  • The SDSS Orion data release contains imaging near the Galactic plane outside of the nominal survey boundaries, and the runs are not part of the standard SDSS data releases. This public release of about 470 square degrees includes the star-forming region NGC 2068/NGC 2071/HH24 and a large part of Barnard's loop. See Finkbeiner et al. 2004 AJ 128, 2577

Last modified: Thurs Oct 2 14:04 ET 2008