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，而由于当今射电望远镜的灵敏度有限，它们的演化尚未被探索。未来的射电望远镜观测到的低通量密度源的主要种群是恒星形成的盘状星系，例如用SKA，可以探测到z ~ 3左右。因此，磁场结构的演变可以通过从遥远的盘状星系的总同步加速器和极化射电发射的演变来研究。法拉第旋转测量中间的盘状星系对极化背景类星体的作用更加强大，将允许用SKA追踪到更高的红移，z ~ 5的磁场演化。在这个项目中，我们的目标是(i)开发星系和星系间磁场的演化模型，（ii）开发利用SKA及其探路者未来射电调查数据研究磁场演化的工具，以及（iii）用现有的深度射电调查测试这些工具。更好地了解年轻星系的磁性历史可能有助于解决关于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.