How do magnetic fields and turbulence affect molecular clouds?

In the context of astronomy, molecular clouds are dense, opaque regions of the interstellar medium where stars are born. Both turbulence and internal magnetic fields play critical roles in the physical state of these clouds by providing essential support against the clouds' own gravity.1

Turbulence

Turbulence manifests as chaotic, large-scale motions within the gas that can create irregular, convoluted shapes. These motions are maintained by the continuous injection of energy from processes such as supernova explosions and strong stellar winds from hot stars. While turbulence contributes to the cloud's pressure support, it also facilitates a cascade of kinetic energy from large scales down to smaller sizes, where it is eventually converted into heat.12

Magnetic Fields

The magnetic field within a molecular cloud is strongly coupled to the gas, as it acts upon embedded electrons that collide with other particles. This coupling forces the gas and the field to move together, with the field exerting a pressure that influences gas motions and interacts with turbulent flows. Additionally, these fields are responsible for the alignment of elongated dust grains, a phenomenon observed through the polarization of starlight.34