A cosmological AMR MHD module for Enzo

TL;DR

This paper introduces a new cosmological magnetohydrodynamics (MHD) module for the Enzo simulation code, enabling detailed studies of magnetic fields in structure formation and star formation.

Contribution

It implements an AMR MHD module in Enzo using a TVD solver and constrained transport, with divergence-free magnetic field interpolation, advancing numerical simulation capabilities.

Findings

Successful testing with MHD caustics, pancake, and galaxy cluster formation.

Demonstrated the module's ability to simulate magnetic fields in cosmological contexts.

Potential applications to first star research.

Abstract

Magnetic fields play an important role in almost all astrophysical phenomena including star formation. But due to the difficulty in analytic modeling and observation, magnetic fields are still poorly studied and numerical simulation has become a major tool. We have implemented a cosmological magnetohydrodynamics package for Enzo which is an AMR hydrodynamics code designed to simulate structure formation. We use the TVD solver developed by S. Li as the base solver. In addition, we employ the constrained transport(CT) algorithm as described by D. Balsara. For interpolation magnetic fields to fine grids we used a divergence free quadratic reconstruction, also described by Balsara. We present results from several test problems including MHD caustics, MHD pancake and galaxy cluster formation with magnetic fields. We also discuss possible applications of our AMR MHD code to first star research.