Galaxy Zoo: The interplay of quenching mechanisms in the group
  environment
  Does the environment of a galaxy directly influence the quenching history of
a galaxy? Here we investigate the detailed morphological structures and star
formation histories of a sample of SDSS group galaxies with both
classifications from Galaxy Zoo 2 and NUV detections in GALEX. We use the
optical and NUV colours to infer the quenching time and rate describing a
simple exponentially declining SFH for each galaxy, along with a control sample
of field galaxies. We find that the time since quenching and the rate of
quenching do not correlate with the relative velocity of a satellite but are
correlated with the group potential. This quenching occurs within an average
quenching timescale of $\sim2.5~\rm{Gyr}$ from star forming to complete
quiescence, during an average infall time (from $\sim 10R_{200}$ to
$0.01R_{200}$) of $\sim 2.6~\rm{Gyr}$. Our results suggest that the environment
does play a direct role in galaxy quenching through quenching mechanisms which
are correlated with the group potential, such as harassment, interactions or
starvation. Environmental quenching mechanisms which are correlated with
satellite velocity, such as ram pressure stripping, are not the main cause of
quenching in the group environment. We find that no single mechanism dominates
over another, except in the most extreme environments or masses. Instead an
interplay of mergers, mass & morphological quenching and environment driven
quenching mechanisms dependent on the group potential drive galaxy evolution in
groups.
