GLASS. VII. H{alpha} maps

In clusters, 30%+/-8% of the galaxies present a regular morphology, mostly consistent with star formation diffused uniformly across the stellar population (mostly in the disk component, when present). The second most common morphology (28%+/-8%) is asymmetric/jellyfish, consistent with ram-pressure stripping or other non-gravitational processes in 18%+/-8% of the cases. Ram-pressure stripping appears significantly less prominent in the field (2%+/-2%), where the most common morphology/mechanism appears to be consistent with minor gas-rich mergers or clump accretion.

This work demonstrates that while environment-specific mechanisms affect galaxy evolution at this redshift, they are diverse and their effects are subtle. A full understanding of this complexity requires larger samples and detailed and spatially resolved physical models.