SIMULATING MAGNETIC FIELDS IN THE ANTENNAE GALAXIES
SIMULATING MAGNETIC FIELDS IN THE ANTENNAE GALAXIES
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DOI：
10.1088/0004-637x/716/2/1438
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发表时间：
2009-11
期刊：
影响因子：
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通讯作者：
H. Kotarba;S. Karl;T. Naab;P. Johansson;K. Dolag;H. Lesch;F. Stasyszyn
中科院分区：
文献类型：
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作者：
H. Kotarba;S. Karl;T. Naab;P. Johansson;K. Dolag;H. Lesch;F. Stasyszyn
我们提出了自洽的高分辨率模拟的NGC 4038/4039（“银河系”），包括星星形成，超新星反馈，和磁场进行的N体/光滑粒子流体动力学（SPH）代码，其中磁流体动力学与SPH方法。我们将原始盘的初始磁场从10−9 G变化到10−4 G。在与超导系统中心区域最佳匹配时，磁场已被压缩和剪切流放大到10 μG的平衡场值，与初始种子场无关。这些模拟证明了星系合并是磁场宇宙演化的有效驱动力的原理。我们提出了一个详细的分析中心重叠区的磁场结构。模拟的无线电和极化图与观测结果在形态和数量上都有很好的一致性。特别是，在我们的模拟中，具有最高同步辐射强度的两个核心以及核心之间和南部潮汐臂根部的规则磁场脊自然发展。这表明模拟能够真实地跟踪高度非线性环境中磁场的演变。我们还讨论了放大效应的相关性，为当今的磁场在层次结构的形成。
We present self-consistent high-resolution simulations of NGC 4038/4039 (the “Antennae galaxies”) including star formation, supernova feedback, and magnetic fields performed with the N-body/smoothed particle hydrodynamic (SPH) code , in which magnetohydrodynamics are followed with the SPH method. We vary the initial magnetic field in the progenitor disks from 10−9 to 10−4 G. At the time of the best match with the central region of the Antennae system, the magnetic field has been amplified by compression and shear flows to an equilibrium field value of ≈10 μG, independent of the initial seed field. These simulations are a proof of the principle that galaxy mergers are efficient drivers for the cosmic evolution of magnetic fields. We present a detailed analysis of the magnetic field structure in the central overlap region. Simulated radio and polarization maps are in good morphological and quantitative agreement with the observations. In particular, the two cores with the highest synchrotron intensity and ridges of regular magnetic fields between the cores and at the root of the southern tidal arm develop naturally in our simulations. This indicates that the simulations are capable of realistically following the evolution of the magnetic fields in a highly nonlinear environment. We also discuss the relevance of the amplification effect for present-day magnetic fields in the context of hierarchical structure formation.