WISE Forced Photometry

This catalog contains “forced photometry” matching between SDSS sources and sources from the Wide-Field Infrared Survey Explorer (WISE; Wright et al. 2010). The WISE forced photometry assumes that all objects detected and measured by SDSS appear in the WISE images with the same morphologies, and then asks how bright those objects should be to best match the WISE data. This is useful because it allows us to extract information from the WISE images using knowledge of the existence and shapes of objects from the higher-resolution SDSS imaging. There is no need for catalog matching, and all sources get a flux measurement, even if the flux is below a formal detection limit (although low-significance flux measurements will understandably still be noisy). This allows, for example, making statistical measures of the WISE flux of classes of SDSS objects (so-called, stacking analyses). The catalog is described in detail in Lang, Hogg, & Schlegel 2016.