NICIL: A stand alone library to self-consistently calculate non-ideal magnetohydrodynamic coefficients in molecular cloud cores

Abstract

In this paper, we introduce Nicil: Non-Ideal magnetohydrodynamics Coefficients and Ionisation Library. Nicil is a stand-alone Fortran90 module that calculates the ionisation values and the coefficients of the non-ideal magnetohydrodynamics terms of Ohmic resistivity, the Hall effect, and ambipolar diffusion. The module is fully parameterised such that the user can decide which processes to include and decide upon the values of the free parameters, making this a versatile and customisable code. The module includes both cosmic ray and thermal ionisation; the former includes two ion species and three species of dust grains (positively charged, negatively charged and neutral), and the latter includes five elements which can be doubly ionised. We demonstrate tests of the module, and then describe how to implement it into an existing numerical code.

13 pgs; accepted to PASA; source code for NICIL: https://bitbucket.org/jameswurster/nicil ; Corrected typos in eqn 47 and in initial conditions of section 4

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Cited by in corpus (16)

• The role of magnetic fields in the formation of protostellar discs
• The impact of the Hall effect during cloud core collapse:implications for circumstellar disk evolution
• The impact of non-ideal magnetohydrodynamics on binary star formation
• Non-ideal magnetohydrodynamics vs turbulence I: Which is the dominant process in protostellar disc formation?
• The impact of non-ideal magnetohydrodynamic processes on discs, outflows, counter-rotation and magnetic walls during the early stages of star formation
• Non-ideal magnetohydrodynamics vs turbulence II: Which is the dominant process in stellar core formation?
• Do we need non-ideal magnetohydrodynamics to model protostellar discs?
• On the origin of magnetic fields in stars II: The effect of numerical resolution
• The widths of magnetised filaments in molecular clouds
• The challenges of modelling microphysics: ambipolar diffusion, chemistry, and cosmic rays in MHD shocks
• Ambipolar diffusion and the molecular abundances in prestellar cores
• The initial magnetic criticality of prestellar cores
• How Does a Protostar Form by Magnetized Gravitational Collapse?
• Resolving numerical star formation: A cautionary tale
• Some Aspects of Rotation and Magnetic Field Morphology in the Infrared Dark Cloud G34.43+00.24
• Non-ideal MHD and protostellar feedback effects on disc formation and evolution in numerical simulations of star cluster formation