Band Merging: After source lists are generated for the 12 and 25 micron bands, the sources are matched or merged between bands. Given a source at 12 micron, the best matched 25 micron source is chosen, and vice versa. The process is made symmetrical using a network reduction logic similar to that used by the 2MASS project.
Acceptable matches: An acceptable match 12 to 25 micron source combination which is less than a given probability cutoff (default 0.1%) and a given pixel separation cutoff (default 5 pixels), all matches beyond these limits are ignored. In cases where a source has more than one acceptable match, the first and second choices are listed in the output table. There may be more than two acceptable matches although this expected to be rare. The total number of acceptable matches is given by the "AN_(band#)" column in the output IPAC table (".merge"). (Band#1 is 12 micron, band#2 is 25 micron.)
Ambiguities: In the case of multiple acceptable matches, there may a certain level of ambiguity in decided which sources should be paired. A set of ambiguity flags is given in the output table. Here are definitions for the ambiguity flags .
Running wiremerge: Wiremerge is executed automatically near the very end of the WIRE data reduction pipeline. It can also be run independent of the pipeline. Here is the syntax. Wiremerge takes the individual band source lists as input and produces a "merged" list of source pairs in IPAC table format. Here are examples of the input source lists for the 12 micron and 25 micron bands.
Output table: The bandmerged source list is written to an IPAC table file with the extension ".merge". Here is an example of an output table file. Here is a description of all the header cards and table columns.