  Studies of star formation in various galaxy cluster mergers have reached
apparently contradictory conclusions regarding whether mergers stimulate star
formation, quench it, or have no effect. Because the mergers studied span a
range of time since pericenter (TSP), it is possible that the apparent effect
on star formation is a function of TSP. We use a sample of 12 bimodal mergers
to assess the star formation as a function of TSP. We measure the equivalent
width of the H-alpha emission line in ${\sim}100$ member galaxies in each
merger, classify galaxies as emitters or non-emitters, and then classify
emitters as star-forming galaxies (SFG) or active galactic nucleus (AGN) based
on the [NII] $\lambda6583$ line. We quantify the distribution of SFG and AGN
relative to non-emitters along the spatial axis defined by the subcluster
separation. The SFG and AGN fractions vary from merger to merger, but show no
trend with TSP. The spatial distribution of SFG is consistent with that of
non-emitters in eight mergers, but show significant avoidance of the system
center in the remaining four mergers, including the three with the lowest TSP.
If there is a connection between star formation activity and TSP, probing it
further will require more precise TSP estimates and more mergers with TSP in
the range of 0-400 Myr.
