Synchrotron intensity gradients as tracers of magnetic field.
Synchrotron intensity gradients as tracers of magnetic field.
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DOI：
10.3847/1538-4357/aaae02
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发表时间：
2017-01
期刊：
影响因子：
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通讯作者：
A. Lazarian;K. Yuen;Hyeseung Lee;Jungyeon Cho
中科院分区：
文献类型：
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作者：
A. Lazarian;K. Yuen;Hyeseung Lee;Jungyeon Cho
基于对磁流体湍流的现代认识，我们提出了一种利用同步辐射的新途径，即利用同步辐射强度梯度追踪天体物理磁场。我们成功地测试了新的技术，使用合成的数据与三维MHD模拟和提供示范的实际效用的技术，通过比较磁场的方向与普朗克同步加速器强度dats与普朗克同步加速器偏振数据获得的方向。我们证明，同步辐射强度梯度（SIG）可以可靠地跟踪磁场中存在的噪声，并可以提供详细的磁场方向图。我们还表明，SIG是相对强大的跟踪磁场，而同步辐射图像的低空间频率被删除。这使得SIG适用于跟踪磁场使用干涉数据与单碟测量缺席。我们讨论了协同使用的SIG与同步加速器偏振，以找到磁场的实际方向和量化的影响，法拉第旋转以及与其他方式研究天体物理磁场。我们测试我们的方法中存在的噪声和分辨率的影响。我们强调使用SIG技术的研究和那些采用最近推出的速度梯度技术，使用光谱数据跟踪磁场的互补性。
On the basis of the modern understanding of MHD turbulence, we propose a new way of using synchrotron radiation, namely using synchrotron intensity gradients for tracing astrophysical magnetic fields. We successfully test the new technique using synthetic data obtained with the 3D MHD simulations and provide the demonstration of the practical utility of the technique by comparing the directions of magnetic field that are obtained with PLANCK synchrotron intensity dats to the directions obtained with PLANCK synchrotron polarization data. We demonstrate that the synchrotron intensity gradients (SIGs) can reliably trace magnetic field in the presence of noise and can provide detailed maps of magnetic-field directions. We also show that the SIGs are relatively robust for tracing magnetic fields while the low spacial frequencies of the synchrotron image are removed. This makes the SIGs applicable to tracing of magnetic fields using interferometric data with single dish measurement absent. We discuss the synergy of using the SIGs together with synchrotron polarization in order to find the actual direction of the magnetic field and quantify the effects of Faraday rotation as well as with other ways of studying astrophysical magnetic fields. We test our method in the presence of noise and the resolution effects. We stress the complementary nature of the studies using the SIG technique and those employing the recently-introduced velocity gradient techniques that traces the magnetic fields using spectroscopic data.