Algorithms in SDSS Data Release 9

Survey-wide

Important considerations that affect all forms of SDSS data

• Bitmasks
• Survey coordinates

Target selection

Algorithms that define how various spectroscopic programs of the SDSS select objects for spectroscopic follow-up

• BOSS Target selection NEW in DR9!
  • Galaxy Target selection
  • Quasar Target selection
  • Standard Star selection
  • Ancillary Target selection
  • BOSS Tiling and Geometry
• SEGUE Target Selection
  • SEGUE-1
  • SEGUE-2
  • SDSS Stellar Targeting - Legacy
  • Calibration Fibers
  • Programs and Plates in SEGUE
  • Accounting for Observational Biases NEW in DR9!
  • Previous Versions of Target Criteria
• Legacy Target selection
  • Main Galaxy Sample
  • Luminous Red Galaxies (LRG)
  • Quasars
  • Stars
  • ROSAT All-Sky Survey sources
  • Serendipity
  • Special Target selection
  • Legacy tiling (assigning fibers & plate centers)

Spectroscopy

Algorithms that process spectra

• Wavelength Calibration
• Spectrophotometry UPDATED in DR9!
• Redshifts, Classification and Velocity Dispersions
• Stellar parameters (SSPP) (in spectro pages) UPDATED in DR9!

Spectroscopic Catalogs

Algorithms that create the spectroscopic catalog data

• Matching spectroscopy to photometry
  UPDATED in DR9!
• Galaxy Properties from the:
  • MPA-JHU group [GalSpec]
  • Portsmouth group [Spectro-photometric] 
    NEW in DR9!
  • Wisconsin group [Principal Component Analysis] 
    NEW in DR9!
• DR9Q Quasar Catalog from the French Participation Group
  NEW in DR9!
• DR9 Lyman-alpha forest sample
  NEW in DR9!

Images

Algorithms that process SDSS images

• Imaging quality flags
• Astrometric calibration UPDATED in DR9!
• Sky measurement
• Creation of imaging masks
• DR7 Photometry QA description (at DR7 site)

Image catalogs

Algorithms that create the imaging catalog data

• Photometric processing flags IMPORTANT!
  • Recommendations
  • Summary of flags
  • Photometric flags detail
  • Full flag details (link to Lupton's page)
• Resolve (removing repeat observations)
• Magnitudes
  • Nanomaggies
  • Asinh
  • Fiber
  • Model
  • cModel
  • Petrosian
  • PSF
  • Extinction
  • Which Magnitude To Use?
  • Radial Profiles
• Classification & Morphology
  • Star/Galaxy Separation
  • Surface Brightnesses
  • Model Fits
  • Ellipticities
  • Isophotal Quantities
  • Adaptive Moments
• Conversion between SDSS ugriz and UBVR_cI_c
• ugriz colors of Vega and the Sun
• Flux calibration
  • Description
  • Parameters
  • Flags
  • Converting SDSS to AB magnitudes
  • Converting SDSS asinh magnitudes to fluxes
  • QA Figures
• Deblending
• Photometric redshifts
• How to reconstruct the PSF at any position