Resolving numerical star formation: A cautionary tale
arXiv:1906.12276
Abstract
Resolution studies of test problems set baselines and help define minimum resolution requirements, however, resolution studies must also be performed on scientific simulations to determine the effect of resolution on the specific scientific results. We perform a resolution study on the formation of a protostar by modelling the collapse of gas through 14 orders of magnitude in density. This is done using compressible radiative non-ideal magnetohydrodynamics. Our suite consists of an ideal magnetohydrodynamics (MHD) model and two non-ideal MHD models, and we test three resolutions for each model. The resulting structure of the ideal MHD model is approximately independent of resolution, although higher magnetic field strengths are realised in higher resolution models. The non-ideal MHD models are more dependent on resolution, specifically the magnetic field strength and structure. Stronger magnetic fields are realised in higher resolution models, and the evolution of detailed structures such as magnetic walls are only resolved in our highest resolution simulation. In several of the non-ideal MHD models, there is an off-set between the location of the maximum magnetic field strength and the maximum density, which is often obscured or lost at lower resolutions. Thus, understanding the effects of resolution on numerical star formation is imperative for understanding the formation of a star.
8 pages, 5 figures. Proceedings of the "14th international SPHERIC workshop", Exeter, United Kingdom, 25-27 June 2019
References in corpus (26)
- Modelling Accretion in Protobinary Systems
- SPLASH: An interactive visualisation tool for Smoothed Particle Hydrodynamics simulations
- Smoothed Particle Hydrodynamics and Magnetohydrodynamics
- An energy-conserving formalism for adaptive gravitational force softening in SPH and N-body codes
- Collapse of Magnetized Singular Isothermal Toroids: II. Rotation and Magnetic Braking
- Smoothed Particle Magnetohydrodynamics II. Variational principles and variable smoothing length terms
- Can non-ideal magnetohydrodynamics solve the magnetic braking catastrophe?
- Collapse of a molecular cloud core to stellar densities: stellar core and outflow formation in radiation magnetohydrodynamics simulations
- Effects of Ohmic and ambipolar diffusion on the formation and evolution of the first cores, protostars and circumstellar discs
- Non-convergence of the critical cooling timescale for fragmentation of self-gravitating discs
- Smoothed Particle Magnetohydrodynamics III. Multidimensional tests and the div B = 0 constraint
- Numerical requirements for simulations of self gravitating and non-self gravitating disks
- Smoothed Particle Magnetohydrodynamics I. Algorithms and tests in one dimension
- Forming spectroscopic massive proto-binaries by disk fragmentation
- Magnetically Controlled Spasmodic Accretion During Star Formation. II. Results
- The collapse of a molecular cloud core to stellar densities using radiation non-ideal magnetohydrodynamics
- Ambipolar diffusion in smoothed particle magnetohydrodynamics
- An Explicit Scheme for Incorporating Ambipolar Diffusion in a Magnetohydrodynamics Code
- NICIL: A stand alone library to self-consistently calculate non-ideal magnetohydrodynamic coefficients in molecular cloud cores
- Impact of the Hall effect in star formation and the issue of angular momentum conservation
- Combining radiative transfer and diffuse interstellar medium physics to model star formation
- Hall effect-driven formation of gravitationally unstable discs in magnetized molecular cloud cores
- On the origin of magnetic fields in stars
- Characterizing gravito-turbulence in 3D: turbulent properties and stability against fragmentation
- A comparison between grid and particle methods on the small-scale dynamo in magnetised supersonic turbulence
- Investigating prescriptions for artificial resistivity in smoothed particle magnetohydrodynamics