Hardcastle Martin J
Astronomy and Mathematics, University of Hertfordshire, School of Physics, College Lane, Hatfield AL10 9AB, UK.
Philos Trans A Math Phys Eng Sci. 2005 Dec 15;363(1837):2711-27. doi: 10.1098/rsta.2005.1667.
The brightest and most numerous discrete radio sources in the sky, radio galaxies and quasars, are powered by twin jets of plasma which emerge at relativistic speeds from very small regions at the centre of large elliptical galaxies, powered by mass infall on to supermassive black holes. The jets can carry material out to very large distances (millions of light years) where it forms balloon-like lobes. Until recently it has been impossible to make definite statements about the energy or the nature of the matter supplied by the jets, or the dynamics of the lobes as they expand into the external medium. This has meant that crucial questions about the generation of radio sources and their effect on their environment have gone unanswered. The situation has been revolutionized by the launch at the start of this decade of a new generation of X-ray observatories, Chandra and XMM-Newton. In this article, I explain why observations with these instruments have made such a difference, what we have learned as a result and why the community remains divided on some important features of the interpretation of the data.
天空中最亮且数量最多的离散射电源，即射电星系和类星体，是由等离子体双喷流提供能量的。这些喷流以相对论速度从大型椭圆星系中心的极小区域喷出，其能量来源于物质落入超大质量黑洞。喷流能够将物质携带到非常遥远的距离（数百万光年），在那里形成气球状的叶瓣。直到最近，人们还无法对喷流所提供的能量、物质的性质，或者叶瓣在向外部介质中扩展时的动力学做出明确的表述。这意味着关于射电源的产生及其对周围环境的影响等关键问题一直没有得到解答。而在这十年初新一代X射线天文台钱德拉X射线天文台和XMM-牛顿卫星的发射彻底改变了这种情况。在本文中，我将解释为什么使用这些仪器进行的观测会带来如此大的改变，我们由此学到了什么，以及为什么学界在数据解释的一些重要特征上仍然存在分歧。
