Gas and star kinematics in cloud-cloud collisions

We model the collision of molecular clouds to investigate the role of the initial properties on the remnants. Our clouds collide and evolve in a background medium that is approximately ten times less dense than the clouds, and we show that this relatively dense background is dynamically important for the evolution of the collision remnants. Given the motion of the clouds and the remnants through the background, we develop, implement, and introduce dynamic boundary conditions. We investigate the effects of the initial cloud mass, velocity, internal turbulence, and impact angle. The initial velocity and its components have the largest effect on the remnant. This affects the spatial extent of the remnant, which affects the number of resulting star clusters and the distribution of their masses. The less extended remnants tend to have fewer, but more massive, clusters. Unlike the clusters, the gas distributions are relatively insensitive to the initial conditions, both the distribution of the bulk gas properties and the gas clumps. In general, cloud collisions are relatively insensitive to their initial conditions when modelled hydrodynamically in a dynamically important background medium.

Automated summary

We investigated the role of initial properties on the remnants of molecular cloud collisions. Our study shows that a relatively dense background medium is dynamically important for the evolution of collision remnants. By studying the motions of clouds and remnants through the background, we introduced dynamic boundary conditions and found that the initial velocity has the largest effect on the remnant, affecting its spatial extent and the resulting star clusters. Gas distributions, however, are relatively insensitive to the initial conditions when simulating cloud collisions hydrodynamically in a dynamically important background medium.