Cosmological evolution of large-scale magnetic fields in galaxies and the intergalactic medium

磁场结构只对附近的盘状星系进行了很好的研究，而由于目前射电望远镜的灵敏度有限，它们的演化还没有被探索过。未来射电望远镜可以观测到的低通量密度源的主要群体是恒星形成盘星系的群体，例如使用SKA，可以探测到约z~3的磁场结构。因此，可以通过远距离盘星系的总同步辐射和偏振射电辐射的演化来研究磁场结构的演化。干涉盘星系朝向极化背景类星体的法拉第旋转测量甚至更强大，并将允许追踪磁场的演化到更高的红移，z~5与SKA。在这个项目中，我们的目标是(一)开发银河系和银河系间磁场的演化模型，(二)开发利用未来与SKA及其探路者进行的射电测量数据来研究磁场演化的工具，以及(三)用现有的深层射电测量来测试这些工具。更好地了解年轻星系的磁性历史，可能有助于解决星系形成和演化的基本宇宙学问题。

The magnetic field structure has been well studied only for nearby disk galaxies while their evolution is unexplored because of the limited sensitivity of present-day radio telescopes. The dominant population of sources at low flux densities observable with future radio telescopes is the population of star-forming disk galaxies which, e.g. with the SKA, would be detected up to about z ~ 3. Hence, the evolution of magnetic field structures can be studied by means of the evolution of total synchrotron and polarized radio emission from distant disk galaxies. Faraday rotation measurements of intervening disk galaxies towards polarized background quasars are even more powerful and will allow the evolution of magnetic fields to be traced to even higher redshifts, z ~ 5 with the SKA. In this project we aim (i) to develop evolutionary models for galactic and intergalactic magnetic fields, (ii) to develop tools for investigating the evolution of magnetic fields using the data from future radio surveys with the SKA and its pathfinders, and (iii) to test these tools with existing deep radio surveys. A better understanding of the history of magnetism in young galaxies may help to solve fundamental cosmological questions on the formation and evolution of galaxies.