Splash Bridge Models of Inclined, Gas-Rich, Direct Galaxy Collisions
  Splash bridges are formed from the direct inelastic collision of gas-rich
galaxies. Recent multi-wavelength observations of the Taffy galaxies, UGC
12914/15, have revealed complicated gas structures in the bridge. We have
upgraded the sticky particle simulation code of Yeager et al., 2019, by adding:
the ability to adjust the relative inclination of the gas discs, the ability to
track cloud-cloud collisions over time, and additional cooling processes.
Inclination effects lead to various morphological features, including
filamentary streams of gas stripped from the smaller galactic disc. The offset
of disc centres at impact determines whether or not these streams flow in a
single direction or multiple directions, even transverse to the motion of the
two galaxies. We also find that, across many types of direct collision,
independent of the inclination or offset, the distributions of weighted Mach
numbers and shock velocities in colliding clouds relax to a very similar form.
There is good evidence of prolonged turbulence in the gas of each splash bridge
for all inclinations and offsets tested, as a result of continuing cloud
collisions, which in turn are the result of shearing and differentially
accelerated trajectories. The number distribution of high velocity shocks in
cloud collisions, produced in our low inclination models, are in agreement with
those observed in the Taffy Galaxies with ALMA, Appleton et al., 2019.
