The 2MASS Survey Extended Source "Reject" Table (XSRT) contains 388 columns of information per source entry (most of which is photometry). Because extended sources are much more complicated than point sources, it takes many more parameters to characterize them. Some parameters are required to describe the spatial extent of a source, and many more are required to characterize the photometry. In addition to a number of standard measures of photometry, the XSRT also reports the magnitude as measured in a number of different fixed-size apertures. The columns are described in the tables below. We have separated the columns according to their basic function and utility.
Photometry algorithms and performance, "Large Aperture Photometry: Profile Fitting, Isophotal & Total Mags," are discussed in Section IV.5e. The information contained in the All-Sky Release Extended Source Catalog (XSC) FAQ and Primer, "How to Use the 2MASS XSC -- FAQ Sheet" (Section II.3b) is directly applicable to the XSRT since the XSC and XSRT were both derived from the same Extended Source Working Database.