Dynamical Ejections of Stars due to an Accelerating Gas Filament
  Observations of the Orion-A integral shaped filament (ISF) have shown
indications of an oscillatory motion of the gas filament. This evidence is
based on both the wave-like morphology of the filament as well as the
kinematics of the gas and stars, where the characteristic velocities of the
stars require a dynamical heating mechanism. As proposed by Stutz and Gould
(2016), such a heating mechanism (the "Slingshot") may be the result of an
oscillating gas filament in a gas-dominated (as opposed to stellar-mass
dominated) system. Here we test this hypothesis with the first
stellar-dynamical simulations in which the stars are subjected to the influence
of an oscillating cylindrical potential. The accelerating, cylindrical
background potential is populated with a narrow distribution of stars. By
coupling the potential to N-body dynamics, we are able to measure the influence
of the potential on the stellar distribution. The simulations provide evidence
that the slingshot mechanism can successfully reproduce several stringent
observational constraints. These include the stellar spread (both in projected
position and in velocity) around the filament, the symmetry in these
distributions, and a bulk motion of the stars with respect to the filament.
Using simple considerations we show that star-star interactions are incapable
of reproducing these spreads on their own when properly accounting for the gas
potential. Thus, properly accounting for the gas potential is essential for
understanding the dynamical evolution of star forming filamentary systems in
the era of Gaia.
