Observational constraints on the structure and generation of magnetic fields in spiral galaxies

星系尺度上宇宙磁场的强度和结构构成了现代天体物理学的基本问题之一，因此近年来它们成为许多新的观测和理论研究的主题。为了进一步限制可能的产生机制，我们建议使用几个波长的偏振同步辐射继续研究盘状星系样本中的三维磁场分布。这些观测也将使我们能够讨论宇宙射线在星系中的传播。星系盘的旋转被认为有助于组织场的大规模结构，而气体动力学被认为是理解可能机制的必要条件。因此，通过绘制这些星系晕中观测到的电离气体的速度场来补充磁场研究。这些观察结果的结合将有助于限制可能的理论情景。

The strength and structure of cosmic magnetic fields on galactic scales constitute one of the fundamental problems in modern astrophysics and they are thus in recent years subject of many new observational and theoretical studies. To further constrain possible generation mechanisms we propose to continue our study of the 3D magnetic field distribution in a sample of disk galaxies using the polarized synchrotron emission at several wavelengths. The observations will also allow us to discuss the propagation of cosmic rays in galaxies. The rotation of galactic disks is believed to help organizing the large scale structure of the fields and the gas dynamics is considered essential for the understanding of possible mechanisms. Therefore the magnetic field studies are supplemented by mapping the velocity field of the ionized gas observed in the haloes of these galaxies. The combination of these observations will help constraining possible theoretical scenarios.