论文标题
在中央分子区域上的三个维度分解磁场
Decomposing Magnetic Fields in Three Dimensions over the Central Molecular Zone
论文作者
论文摘要
在传统技术中，测量星际介质中的磁场并沿视路获得分布非常具有挑战性。速度梯度技术（VGT）利用磁流失动力（MHD）湍流的各向异性提供了一种有吸引力的解决方案。针对中央分子区域（CMZ），我们通过将VGT应用于$ \ rm ^{12} CO $和$ \ rm ^{13} CO $（J = 1-0）数据数据库来测试此方法。我们首先使用Scousepy算法将CO线排放分解为单独的速度组件，然后我们通过VGT构建了伪Stokes参数，以三维尺寸绘制平面磁场。我们提出分解的磁场图并研究其意义。虽然显示的磁场磁场方向表明与353 GHz的Planck调查的极化粉尘发射一致，但单个速度组件可能显示出不同的磁场。我们根据分解磁场提出了CMZ中磁场构型的方案。特别是，我们观察到SGR B2附近的致密团块中的几乎垂直磁场方向，以及SGR A*周围的流出区域的变化。与CMZ中膨胀环相关的两个高速结构显示出不同的旋转磁场结构。这些结果证明了VGT分解速度或密度依赖性磁性结构的潜在功率。
Measuring magnetic fields in the interstellar medium and obtaining their distribution along line-of-sight is very challenging with the traditional techniques. The Velocity Gradient Technique (VGT), which utilizes anisotropy of magnetohydrodynamic (MHD) turbulence, provides an attractive solution. Targeting the central molecular zone (CMZ), we test this approach by applying the VGT to $\rm ^{12}CO$ and $\rm ^{13}CO$ (J = 1-0) data cubes. We first used the SCOUSEPY algorithm to decompose the CO line emissions into separate velocity components, and then we constructed pseudo-Stokes parameters via the VGT to map the plane-of-the-sky magnetic fields in three-dimension. We present the decomposed magnetic field maps and investigate their significance. While the line-of-sight integrated magnetic field orientation is shown to be consistent with the polarized dust emission from the Planck survey at 353 GHz, individual velocity components may exhibit different magnetic fields. We present a scheme of magnetic field configuration in the CMZ based on the decomposed magnetic fields. In particular, we observe a nearly vertical magnetic field orientation in the dense clump near the Sgr B2 and a change in the outflow regions around the Sgr A*. Two high-velocity structures associated with an expanding ring in the CMZ show distinct swirling magnetic field structures. These results demonstrate the potential power of the VGT to decompose velocity or density-dependent magnetic structures.
