DOI : will be inserted by hand later ) X-ray emission from expanding cocoons
DOI : will be inserted by hand later ) X-ray emission from expanding cocoons
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2008
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对河外放射源的 X 射线观测显示出射电等离子体与 X 射线发射环境气体之间相互作用的有力证据。在本文中，我们通过数值模拟对这种相互作用进行了详细研究。我们研究了轴对称超音速射流在等温 King 大气中的传播，并分析了所得 X 射线特性的演变及其对射流物理参数的依赖性。我们证明存在两种截然不同的、观察上不同的相互作用机制，具有强冲击和弱冲击。在第一种情况下，预计 X 射线发射会增强，而在第二种情况下，我们预计 X 射线发射不足与茧一致。通过分析模型和数值模拟结果的比较，我们讨论了这两种状态之间的转变对射流参数的依赖性，并发现平均控制量是射流动功率。然后我们讨论如何使用观察到的射流来约束射流属性。
X-ray observations of extragalactic radiosources show strong evidences of interaction between the radio emitting plasma and the X-ray emitting ambient gas. In this paper we perform a detailed study of this interaction by numerical simulations. We study the propagation of an axisymmetric supersonic jet in an isothermal King atmosphere and we analyze the evolution of the resulting X-ray properties and their dependence on the jet physical parameters. We show the existence of two distinct and observationally different regimes of interaction, with strong and weak shocks. In the first case shells of enhanced X-ray emission are to be expected, while in the second case we expect deficit of X-ray emission coincident with the cocoon. By a comparison between analytical models and the results of our numerical simulations, we discuss the dependence of the transition between these two regimes on the jet parameters and we find that the mean controlling quantity results to be the jet kinetic power. We then discuss how the observed jets can be used to constrain the jet properties.