The impact of non-ideal magnetohydrodynamics on binary star formation

Abstract

We investigate the effect of non-ideal magnetohydrodynamics (MHD) on the formation of binary stars using a suite of three-dimensional smoothed particle magnetohydrodynamics simulations of the gravitational collapse of one solar mass, rotating, perturbed molecular cloud cores. Alongside the role of Ohmic resistivity, ambipolar diffusion and the Hall effect, we also examine the effects of magnetic field strength, orientation and amplitude of the density perturbation. When modelling sub-critical cores, ideal MHD models do not collapse whereas non-ideal MHD models collapse to form single protostars. In super-critical ideal MHD models, increasing the magnetic field strength or decreasing the initial density perturbation amplitude decreases the initial binary separation. Strong magnetic fields initially perpendicular to the rotation axis suppress the formation of binaries and yield discs with magnetic fields ~10 times stronger than if the magnetic field was initially aligned with the rotation axis. When non-ideal MHD is included, the resulting discs are larger and more massive, and the binary forms on a wider orbit. Small differences in the super-critical cores caused by non-ideal MHD effects are amplified by the binary interaction near periastron. Overall, the non-ideal effects have only a small impact on binary formation and early evolution, with the initial conditions playing the dominant role.

Accepted to MNRAS. 18 pages, 20 figures, 1 appendix

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Cited by in corpus (15)

• On the diversity and statistical properties of protostellar discs
• Decoupling of Magnetic Fields in Collapsing Protostellar Envelopes and Disk Formation and Fragmentation
• Impact of Protostellar Outflows on Turbulence and Star Formation Efficiency in Magnetized Dense Cores
• Formation and Evolution of Disks around Young Stellar Objects
• Disc formation and fragmentation using radiative non-ideal magnetohydrodynamics
• Binary Star Formation and the Outflows from their Discs
• Magnetic fields in circumstellar disks: The potential of Zeeman observations
• Star-disk alignment in the protoplanetary disks: SPH simulation of the collapse of turbulent molecular cloud cores
• Do we need non-ideal magnetohydrodynamics to model protostellar discs?
• Dust charge distribution in the interstellar medium
• Impact of the Hall effect in star formation : improving the angular momentum conservation
• Conditions for justifying single-fluid approximation for charged and neutral dust fluids and a smoothed particle magnetohydrodynamics method for dust-gas mixture
• Twin Jets and Close Binary Formation
• Ambipolar diffusion and the molecular abundances in prestellar cores
• Investigating prescriptions for artificial resistivity in smoothed particle magnetohydrodynamics