论文标题
带有MASCLET的宇宙磁场：用于星系簇的应用
Cosmic magnetic fields with MASCLET: an application to galaxy clusters
论文作者
论文摘要
我们描述并测试了自适应网状精炼（AMR）宇宙学守则的新版本。该代码的新版本包括其先前版本的所有成分，以及在理想的磁通动力学（MHD）近似下对磁场演变的描述。为了保留MHD的无差异状况，Dedner等人的原始散射清洁算法。 （2002）已实施。我们提供了一组知名的1D和2D测试，例如几个冲击管问题，快速转子和Orszag-Tang涡流。在所有测试中，代码的性能非常出色，在2D测试中，估计的中值相对误差为$ \ nabla \ cdot {\ bf b} $，用于快速转子测试的小于$ 5 \ times 10^{ - 5} $，$ 5 \ $ 5 \ times times 10^{ - 3} $用于ORSZAG-TANG-TANG-TANG-TANG VORTEX。作为代码的天体物理应用，我们提供了一个宇宙学盒子的模拟，其中40个共同的MPC侧长度，其中对强度0.1 ng的原始均匀均匀磁场进行了播种。该模拟显示了如何沿气体丝引导的磁场，并在星系簇中浓缩并放大。与纯压缩预期的值的比较表明，由于集群中央区域的湍流引起的磁场的额外扩增。 $ \ sim1μ$ g的订单的值在$ z \ sim 0 $的集群中获得，中位相对错误的中位相对错误为$ \ nabla \ cdot \ cdot {\ bf b} $低于0.4 \％\％。讨论了对磁场动力学及其在未来设施中可能的观测值的正确描述的含义。
We describe and test a new version of the adaptive mesh refinement (AMR) cosmological code MASCLET. The new version of the code includes all the ingredients of its previous version plus a description of the evolution of the magnetic field under the approximation of the ideal magneto-hydrodynamics (MHD). To preserve the divergence-free condition of MHD, the original divergence cleaning algorithm of Dedner et al. (2002) is implemented. We present a set of well-known 1D and 2D tests, such as several shock-tube problems, the fast rotor and the Orszag-Tang vortex. The performance of the code in all the tests is excellent with estimated median relative errors of $\nabla \cdot {\bf B}$ in the 2D tests smaller than $5 \times 10^{-5}$ for the fast rotor test, and $5 \times 10^{-3}$ for the Orszag-Tang vortex. As an astrophysical application of the code, we present a simulation of a cosmological box of 40 comoving Mpc side length in which a primordial uniform comoving magnetic field of strength 0.1 nG is seeded. The simulation shows how the magnetic field is channelled along the filaments of gas and is concentrated and amplified within galaxy clusters. Comparison with the values expected from pure compression reveals an additional amplification of the magnetic field caused by turbulence in the central region of the cluster. Values of the order of $\sim 1 μ$G are obtained in clusters at $z\sim 0$ with median relative errors of $\nabla \cdot {\bf B}$ below 0.4\%. The implications of a proper description of the dynamics of the magnetic field and their possible observational counterparts in future facilities are discussed.
