Special columns

If catpair is invoked with the option spcol=true then three special columns giving details of the pairing for each object will be included in the output catalogue. These columns are:

SEPN

the separation between the paired primary and secondary objects,

PMULT

the number of matches in the primary,

SMULT

the number of matches in the seconary.

Usually fields in columns PMULT and SMULT will have a value of one for paired objects. However, in cases where there were multiple matches for the pair the values will be larger. See Section , below for a discussion of the handling of multiple matches.