Despite their relative sparseness, during the recent years it has become more and more clear that extragalactic radio sources (both AGN and star-forming galaxies) constitute an extremely interesting mix of populations, not only because of their intrinsic value, but also for their fundamental role in shaping our universe the way we see it today. Indeed, radio-active AGN are now thought to be the main players involved in the evolution of massive galaxies and clusters. At the same time, thanks to the possibility of being observed up to very high redshifts, radio galaxies can also provide crucial information on both the star-formation history of our universe and on its large-scale structure properties and their evolution. In the light of present and forthcoming facilities such as LOFAR, MeerKAT and SKA that will probe the radio sky to unprecedented depths and widths, this review aims at providing the current state of the art on our knowledge of extragalactic radio sources in connection with their hosts, large-scale environments and cosmological context.

尽管它们相对稀疏，但近年来，越来越清楚的是，河外射电源（活动星系核和恒星形成星系）构成了一个极其有趣的群体组合，不仅因为它们的内在价值，还因为它们的基本原理在塑造我们今天所看到的宇宙方面发挥着重要作用。事实上，放射性活动星系核现在被认为是参与大质量星系和星团演化的主要参与者。与此同时，由于有可能观测到非常高的红移，射电星系还可以提供有关宇宙恒星形成历史及其大尺度结构特性及其演化的重要信息。鉴于现有和即将推出的 LOFAR、MeerKAT 和 SKA 等设施将探测射电天空到前所未有的深度和宽度，本次审查旨在提供我们对河外射电源与其宿主相关的最新知识、大尺度环境和宇宙学背景。