Mapping of the Structure of the Galactic Magnetic Field with Velocity Gradients: Test Using Star Light Polarization
Mapping of the Structure of the Galactic Magnetic Field with Velocity Gradients: Test Using Star Light Polarization
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DOI：
10.3847/1538-4357/ab0552
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发表时间：
2018-05
期刊：
影响因子：
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通讯作者：
Diego F. González-Casanova;A. Lazarian
中科院分区：
文献类型：
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作者：
Diego F. González-Casanova;A. Lazarian
我们将速度通道梯度(VCHGs)和折合速度质心梯度(RVCGs)应用于HI数据(实验室调查)，得到了磁场的天空平面分量(POS)作为相对速度的函数。假设银河系自转曲线，我们将相对速度转换为距离，构建了天球每一点的POS磁场的第一张地图，作为距离的函数。为了测试我们的3D分布的准确性，我们使用了一组距离恒星偏振星表已知距离的恒星。我们将VChGs和RVCGs得到的偏振方向与星光的偏振方向进行了比较。得到的磁场与测量的极化方向之间有很好的对应关系，验证了这种探测银河系POS三维磁场结构的新方法的准确性。
We apply Velocity Channel Gradients (VChGs) and Reduced Velocity Centroids Gradients (RVCGs) to H i data (the LAB survey), obtaining the plane-of-sky component (POS) of the magnetic field as a function of the relative velocity. Assuming a galactic rotation curve, we transformed the relative velocities to distances, constructing the first map of the POS magnetic field at every point of the celestial sphere as a function of the distance. To test the accuracy of our 3D distribution, we used a set of stars with known distances from the stellar polarization catalog. We compared the polarization directions that we obtain with the VChGs and RVCGs against the starlight polarization directions. We find a good correspondence between the derived magnetic field and measured polarization directions, which testifies to the accuracy of this new way of probing the 3D galactic POS magnetic field structure.