Formation of Massive Molecular Cloud Cores by Cloud-cloud Collision

TL;DR

This study uses 3D magnetohydrodynamics simulations to show that cloud-cloud collisions can create massive, filamentary molecular cloud cores with strong magnetic fields, potentially triggering massive star formation.

Contribution

It demonstrates that cloud-cloud collisions can produce massive, magnetized, filamentary cores with high Jeans mass, advancing understanding of massive star formation mechanisms.

Findings

Massive cores form behind shock waves in collisions.

Magnetic fields are amplified and aligned perpendicular to filaments.

Formed cores are filamentary and magnetized.

Abstract

Recent observations of molecular clouds around rich massive star clusters including NGC3603, Westerlund 2, and M20 revealed that the formation of massive stars could be triggered by a cloud-cloud collision. By using three-dimensional, isothermal, magnetohydrodynamics simulations with the effect of self-gravity, we demonstrate that massive, gravitationally unstable, molecular cloud cores are formed behind the strong shock waves induced by the cloud-cloud collision. We find that the massive molecular cloud cores have large effective Jeans mass owing to the enhancement of the magnetic field strength by shock compression and turbulence in the compressed layer. Our results predict that massive molecular cloud cores formed by the cloud-cloud collision are filamentary and threaded by magnetic fields perpendicular to the filament.