NYU Value-Added Galaxy Catalog
This file contains the SWIRE catalog matched to the object_sdss_imaging file.
This file only contains unique matches to object_sdss_imaging objects. In order to access the full catalog, look in the file:
$VAGC_REDUX/spitzer/swire_catalog.fitsThe file object_swire.fits has a column SWIRE_POSITION which yields the zero-indexed position in the full swire_catalog.fits file.
The SWIRE catalog has deep ugriz imaging of their own for all its sources. However, note that there are large shifts in their magnitude system relative to AB described by their documentation. In addition, in my experience even with these shifts their calibration (or at least the magnitudes of extended sources) differs substantially from SDSS and is very likely to be wrong.