Modeling Turbulence in Galactic Centers
  Turbulence is a prevalent phenomenon in the interstellar medium, and in
particular, the environment at the centers of galaxies. For example, detailed
observations of the Milky Way's Central Molecular Zone (CMZ) revealed that it
has a complex and turbulent structure. Turbulence on galactic scales is often
modeled using star formation and feedback. However, these effects do not appear
to be sufficient for explaining the high-velocity dispersion observed in the
CMZ, indicating that additional gas-stirring processes are likely to be
operating. Here we introduce a proof-of-concept method to drive turbulence in
gas that orbits under the influence of a galactic potential. Instead of relying
on a particular physical mechanism, we have adopted a Fourier forcing module
and have applied it using a Smoothed Particle Hydrodynamics code. To test our
method, we performed simulations of a simplistic model of the CMZ. Our
turbulence injection method is capable of balancing the self-gravity of the
gas, which allows us to run the simulations for long timescales and thereby
follow the evolution of the CMZ. Our results show that turbulence induces a
flocculent spiral pattern in our model, analogous to that found in
galactic-scale simulations. Furthermore, we find that our turbulence injection
method induces inward migration of gas, a result consistent with previous
numerical simulations. We submit that this injection method is a promising new
tool to simulate turbulence in galactic centers.
