Dynamics of the Parker-Jeans instability of gaseous disks including the effect of cosmic rays

TL;DR

This study investigates how cosmic rays influence the Parker-Jeans instability in magnetized gaseous disks through 3D MHD simulations, revealing their role in filament formation and the impact of diffusion and rotation.

Contribution

It introduces the first detailed 3D MHD simulation analysis of cosmic ray effects on Parker-Jeans instability in gaseous disks, including diffusion and rotation effects.

Findings

Cosmic rays significantly affect filament and clump formation.

Diffusion coefficient determines filament orientation relative to magnetic fields.

Rotation influences the instability dynamics.

Abstract

The effect of cosmic rays on the Parker-Jeans instability in magnetized self-gravitating gaseous disks is studied by three-dimensional magnetohydrodynamic (MHD) simulations with cosmic rays taken as a massless fluid with notable pressure. Cosmic ray diffusion along the magnetic field is taken into account in the simulation. The initial configuration of the disk is a magnetized cold gas slab sandwiched between hot corona (on top and bottom). We show that cosmic rays play an important role in the formation of filaments or clumps in some parameter regimes. In a certain range of the thickness of the gas slab, the cosmic ray diffusion coefficient plays a decisive role in determining whether the filaments lie along or perpendicular to the magnetic field. We also consider the effect of rotation on the system.