GMC Collisions as Triggers of Star Formation. VII. The Effect of Magnetic Field Strength on Star Formation

TL;DR

This study uses magnetohydrodynamic simulations to explore how varying magnetic field strengths influence star formation within giant molecular clouds, revealing that magnetic criticality significantly impacts star formation rates and efficiencies.

Contribution

It provides new insights into the role of magnetic field strength and cloud collisions in star formation, extending previous models with detailed MHD simulations and sub-grid physics.

Findings

Magnetic criticality affects gas evolution and star formation.

GMC collisions increase star formation in supercritical conditions.

Magnetic criticality can inhibit star formation in certain environments.

Abstract

We investigate the formation of stars within giant molecular clouds (GMCs) evolving in environments of different global magnetic field strength and large-scale dynamics. Building upon a series of magnetohydrodynamic (MHD) simulations of non-colliding and colliding GMCs, we employ density- and magnetically-regulated star formation sub-grid models in clouds which range from moderately magnetically supercritical to near critical. We examine gas and star cluster morphologies, magnetic field strengths and relative orientations, pre-stellar core densities, temperatures, mass-to-flux ratios and velocities, star formation rates and efficiencies over time, spatial clustering of stars, and kinematics of the stars and natal gas. The large scale magnetic criticality of the region greatly affects the overall gas evolution and star formation properties. GMC collisions enhance star formation rates and efficiencies in magnetically supercritical conditions, but may actually inhibit them in the magnetically critical case. This may have implications for star formation in different Galactic environments such as the Galactic Center and the main Galactic disk.