Cosmological Simulations using GCMHD+

TL;DR

This paper introduces GCMHD+, a new MHD simulation code for cosmological studies, demonstrating its accuracy and application in simulating galaxy cluster magnetic field amplification during formation.

Contribution

GCMHD+ is a novel MHD implementation for the GCD+ code, validated against ATHENA, and applied to simulate magnetic field evolution in galaxy cluster formation.

Findings

GCMHD+ shows good agreement with ATHENA in test problems.

A primordial magnetic field of 10^-11 G is amplified by a factor of 10^3.

Simulation results align with other magnetic cluster studies.

Abstract

Radio observations of galaxy clusters show that the intra cluster medium is permeated by \mu G magnetic fields. The origin and evolution of these cosmological magnetic fields is currently not well understood and so their impact on the dynamics of structure formation is not known. Numerical simulations are required to gain a greater understanding and produce predictions for the next generation of radio telescopes. We present the galactic chemodynamics smoothed particle magnetohydrodynamic (SPMHD) code (GCMHD+), which is an MHD implementation for the cosmological smoothed particle hydrodynamic code GCD+. The results of 1, 2 and 3 dimensional tests are presented and the performance of the code is shown relative to the ATHENA grid code. GCMHD+ shows good agreement with the reference solutions produced by ATHENA. The code is then used to simulate the formation of a galaxy cluster with a simple primordial magnetic field embedded in the gas. A homogeneous seed field of 10^-11 G is amplified by a factor of 10^3 during the formation of the cluster. The results show good agreement with the profiles found in other magnetic cluster simulations of similar resolution.