Magnetohydrodynamics on an unstructured moving grid

摘要: Magnetic fields play an important role in astrophysics on a wide variety of scales, ranging from the Sun and compact objects to galaxies galaxy clusters. Here we discuss novel implementation ideal magnetohydrodynamics (MHD) moving-mesh code arepo which combines many advantages Eulerian Lagrangian methods single computational technique. The employed grid is defined as Voronoi tessellation set mesh-generating points can move along with flow, yielding automatic adaptivity mesh substantial reduction advection errors. Our scheme solves MHD Riemann problem rest frame interfaces using HLLD solver. To satisfy divergence constraint magnetic field multiple dimensions, Dedner cleaning method applied. In standard test problems, show that new produces accurate results kept sufficiently small closely preserve correct physical solution. We also apply two first application namely supersonic turbulence spherical collapse magnetized cloud. verify able handle both problems well, demonstrating applicability this version range astrophysics.