WISE photometry for 400 million SDSS sources

Understand

We present photometry of images from the Wide-Field Infrared Survey Explorer (WISE; Wright et al.

• 2010) of over 400 million sources detected by the Sloan Digital Sky Survey (SDSS; York et al.
• 2000).
• We use a "forced photometry" technique, using measured SDSS source positions, star-galaxy separation and galaxy profiles to define the sources whose fluxes are to be measured in the WISE images.