Strong Dusty Bursts of Star Formation in Galaxies Falling into the Cluster RX J0152.7−1357

$yr$^{-1}$, significantly higher than in previous estimates from optical data. Most of the MIR-emitting galaxies also have optical emission lines, but a few do not and hence have completely hidden bursts of star formation or AGN activity. An excess of MIR-emitting galaxies is seen in the cluster in comparison to the field at the same redshift. The MIR cluster members are more associated with previously detected infalling late type galaxies rather than triggered by the ongoing merging of bigger X-ray clumps. Rough estimates also show that ram pressure may not be capable of stripping the gas away from cluster outskirt galaxies but it may disturb the gas enough to trigger the star formation activity. Harassment can also play a role if for example these galaxies belong to poor galaxy groups. Thus, bursts of star formation occur in the cluster environment and could also help consume the galaxy gas content in addition to ram pressure, harassment or galaxy-galaxy strong interactions.

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