Ram pressure stripping candidates in the Coma Cluster: Evidence for enhanced star formation
Abstract
The Coma cluster is the nearest massive ($M \gtrsim
10^{15}\,\mathrm{M_\odot}$) galaxy cluster, making it an excellent laboratory
to probe the influence of the cluster environment on galaxy star formation.
Here, we present a sample of 41 galaxies with disturbed morphologies consistent
with ram pressure stripping. These galaxies are identified visually using
high-quality, multi-band imaging from the Canada-France-Hawaii telescope
covering ~9 $\mathrm{deg^2}$ of the Coma cluster. These "stripping candidates"
are clear outliers in common quantitative morphological measures, such as
concentration-asymmetry and Gini-$M_{20}$, confirming their disturbed nature.
Based on the orientations of observed asymmetries, as well as the galaxy
positions in projected phase-space, these candidates are consistent with
galaxies being stripped shortly after infall onto the Coma cluster. Finally,
the stripping candidates show enhanced star formation rates, both relative to
"normal" star-forming Coma galaxies and isolated galaxies in the field. Ram
pressure is likely driving an enhancement in star formation during the
stripping phase, prior to quenching. On the whole, ram pressure stripping
appears to be ubiquitous across all regions of the Coma cluster.