The Grism lens-amplified survey from space (GLASS). VII. The diversity
  of the distribution of star formation in cluster and field galaxies at
  0.3<z<0.7
  Exploiting the slitless spectroscopy taken as part of the Grism
Lens-Amplified Survey from Space (GLASS), we present an extended analysis of
the spatial distribution of star formation in 76 galaxies in 10 clusters at
0.3< z <0.7. We use 85 foreground and background galaxies in the same redshift
range as a field sample. The samples are well matched in stellar mass
(10^8-10^11 M_sun) and star formation rate (0.5-50 M_sun/yr). We visually
classify galaxies in terms of broad-band morphology, Halpha morphology and
likely physical process acting on the galaxy. Most Halpha emitters have a
spiral morphology (41+/-8% in clusters, 51+/-8% in the field), followed by
mergers/interactions (28+/-8%, 31+/-7%, respectively) and early-type galaxies
(remarkably as high as 29+/-8% in clusters and 15+/-6% in the field). A
diversity of Halpha morphologies is detected, suggesting a diversity of
physical processes. 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 subtle. A full understanding of this
complexity requires larger samples and detailed and spatially resolved physical
models.
