Reorienting MHD Colliding Flows: A Shock Physics Mechanism for Generating Filaments Normal to Magnetic Fields

Abstract

We present numerical simulations of reorienting oblique shocks that form in the collision layer between magnetized colliding flows. Reorientation aligns parsec-scale post-shock filaments normal to the background magnetic field. We find that reorientation begins with pressure gradients between the collision region and the ambient medium. This drives a lateral expansion of post-shock gas, which reorients the growing filament from the outside-in (i.e. from the flow-ambient boundary, toward the colliding flows axis). The final structures of our simulations resemble polarization observations of filaments in Taurus and Serpens South, as well as the integral-shaped filament in Orion A. Given the ubiquity of colliding flows in the interstellar medium, shock reorientation may be relevant to the formation of filaments normal to magnetic fields.

In press, MNRAS, 11 pages, 13 figures

References in corpus (7)

• From the warm magnetized atomic medium to molecular clouds
• Formation of Magnetized Prestellar Cores with Ambipolar Diffusion and Turbulence
• Simulating Magnetohydrodynamical Flow with Constrained Transport and Adaptive Mesh Refinement; Algorithms & Tests of the AstroBEAR Code
• CARMA Large Area Star Formation Survey: Observational Analysis of Filaments in the Serpens South Molecular Cloud
• Aspect Ratio Dependence of the Free-Fall Time for Non-Spherical Symmetries
• CARMA Large Area Star Formation Survey: Structure and Kinematics of Dense Gas in Serpens Main
• Molecular cloud formation in high-shear, magnetized colliding flows

Cited by in corpus (11)

• The molecular cloud lifecycle
• Dust survival rates in clumps passing through the Cas A reverse shock I: results for a range of clump densities
• Alignment Between Protostellar Outflows and Filamentary Structure
• Dense gas formation in the Musca filament due to the dissipation of a supersonic converging flow
• Probing the cold magnetized Universe with SPICA-POL (B-BOP)
• Dust survival rates in clumps passing through the Cas A reverse shock -- II. The impact of magnetic fields
• Simulating observable structures due to a perturbed interstellar medium in front of astrospheric bow shocks in 3D MHD
• The properties of clusters, and the orientation of magnetic fields relative to filaments, in magnetohydrodynamic simulations of colliding clouds
• Bimodal Behavior and Convergence Requirement in Macroscopic Properties of the Multiphase Interstellar Medium Formed by Atomic Converging Flows
• On the 3D Curvature and Dynamics of the Musca filament
• On the role of magnetic fields in star formation