论文标题
基于磁矢量图的NGC 3627的大规模磁场结构
Large-scale magnetic field structure of NGC 3627 based on magnetic vector map
论文作者
论文摘要
我们分析了Stokes $ i $，$ Q $和$ u $ in C-和X频段的数据，并研究了NGC 3627的大规模磁场结构。每个乐队的极化强度和角度使用Stokes $ Q $和$ u $ $地图得出。使用极化角度图计算旋转度量。此外，通过假设用宇宙射线电子进行能量齐射来计算磁场强度。磁场的结构与螺旋臂很好地排列，这与前者中的研究相一致。我们将磁性矢量重建方法应用于NGC 3627，以得出磁性矢量图，该图表明，北部和南部磁盘分别在内向和外向磁向量中占主导地位。此外，我们讨论了NGC 3627中磁场的大规模结构，并观察到该结构本质上是双对称的螺旋，并且磁场模式的数量为$ M _ {\ rm B} = 1 $在Galaxy外部区域。此外，NGC 3627具有两个螺旋臂的模式，在光学图像中清晰可见。螺旋臂与磁场模式的比率为2：1。就NGC 3627而言，可以通过螺旋臂的重力电位引起的参数共振产生大型磁场。
We analyzed the data of Stokes $I$, $Q$, and $U$ in C- and X-bands and investigated the large-scale magnetic field structure of NGC 3627. The polarization intensity and angle in each band were derived using Stokes $Q$ and $U$ maps. The rotation measure was calculated using the polarization-angle maps. Moreover, the magnetic field strength was calculated by assuming energy equipartition with the cosmic ray electrons. The structure of the magnetic field was well aligned with the spiral arms, which were consistent with those in the former studies. We applied the magnetic vector reconstruction method to NGC 3627 to derive a magnetic vector map, which showed that northern and southern disks were dominant with inward and outward magnetic vectors, respectively. Furthermore, we discussed the large-scale structure of the magnetic field in NGC 3627 and observed that the structure is bi-symmetric spiral in nature, and that the number of magnetic field mode is $ m_{\rm B} = 1 $ in outer region of galaxy. In addition, NGC 3627 has a mode of two spiral arms that were clearly visible in an optical image. The ratio of the mode of spiral arms to that of magnetic field is 2:1. In terms of NGC 3627, the large-scale magnetic field may be generated via the parametric resonance induced by the gravitational potential of the spiral arms.
