Simulations of extragalactic magnetic fields and of their observables
Simulations of extragalactic magnetic fields and of their observables
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DOI：
10.1088/1361-6382/aa8e60
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发表时间：
2017-11
影响因子：
3.5
通讯作者：
F. Vazza;F. Vazza;F. Vazza;M. Brüggen;C. Gheller;S. Hackstein;D. Wittor;P. Hinz
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文献类型：
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作者：
F. Vazza;F. Vazza;F. Vazza;M. Brüggen;C. Gheller;S. Hackstein;D. Wittor;P. Hinz
河外磁场的起源仍然知之甚少。基于一套专用的宇宙磁流体动力学模拟和ENZO代码，我们对不同的模型进行了调查，这些模型可能导致了今天星系和星系团中的磁场。这些模型的结果在星团外围、细丝、薄片和空隙中有所不同，我们使用这些模拟来寻找磁发生的观测特征。通过这些模拟，我们预测了在宇宙网同步辐射的射电观测中，在法拉第旋转中，在超高能量宇宙射线的传播中，在宇宙距离的快速射电暴的极化信号中，以及在遥远的blazars光谱中，银河系外磁场的信号。一般来说，在原始情景中，当今的磁场源于弱（≤nG）均匀种子场的放大，导致磁场比天体物理情景更均匀，相对更容易观测，在原始情景中，当今的磁场是由恒星和活动星系触发的反馈过程的产物。在不久的将来，宇宙磁场起源的最佳证据很可能来自同步加速器发射和法拉第旋转在大型结构外围观察到的结合。
The origin of extragalactic magnetic fields is still poorly understood. Based on a dedicated suite of cosmological magneto-hydrodynamical simulations with the ENZO code we have performed a survey of different models that may have caused present-day magnetic fields in galaxies and galaxy clusters. The outcomes of these models differ in cluster outskirts, filaments, sheets and voids and we use these simulations to find observational signatures of magnetogenesis. With these simulations, we predict the signal of extragalactic magnetic fields in radio observations of synchrotron emission from the cosmic web, in Faraday rotation, in the propagation of ultra high energy cosmic rays, in the polarized signal from fast radio bursts at cosmological distance and in spectra of distant blazars. In general, primordial scenarios in which present-day magnetic fields originate from the amplification of weak (⩽nG) uniform seed fields result in more homogeneous and relatively easier to observe magnetic fields than astrophysical scenarios, in which present-day fields are the product of feedback processes triggered by stars and active galaxies. In the near future the best evidence for the origin of cosmic magnetic fields will most likely come from a combination of synchrotron emission and Faraday rotation observed at the periphery of large-scale structures.