The long-term effect of radio sources on the intracluster medium
The long-term effect of radio sources on the intracluster medium
复制标题
无线电源对簇内介质的长期影响
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
P. Alexander
中科院分区：
文献类型：
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作者：
J. F. Basson;P. Alexander
我们对β剖面冷却流团簇中的FR II射电源进行了三维流体动力学模拟。团簇气体的冷却效应被纳入ZEUS-MP代码的修改版本中。这些模拟不仅跟踪射电源的活跃阶段，而且跟踪射电源的喷流关闭后长达2 Gyr的长期行为。我们发现，正如预期的那样，射电源有一个显着的冷却流的影响，而它是活跃的，但是，我们也发现，对集群的射电源的影响是长期的。一个浮力驱动的对流被建立作为残余的无线电源通过集群的集群拖动从集群核心的材料上升。虽然中央Mpc的集群恢复到有一个冷却流，这种不对称的对流是能够消除冷气体聚集在集群核心，确实有一个净流出持续的时间尺度约一个数量级长于源是活跃的时间或更长。对流也可以提供一种机制，以提高在大的集群半径的集群气体的金属性。
We have performed three-dimensional hydrodynamical simulations of FR II radio sources in β-profile cooling-flow clusters. The effects of cooling of the cluster gas were incorporated into a modified version of the ZEUS-MP code. The simulations followed not only the active phase of the radio source, but also the long-term behaviour for up to 2 Gyr after the jets of the radio source were switched off. We find as expected that the radio source has a significant effect on the cooling flow while it is active; however, we also find that the effects of the radio source on the cluster are long-lived. A buoyancy-driven convective flow is established as the remnants of the radio source rise through the cluster dragging material from the cluster core. Although the central Mpc of the cluster reverts to having a cooling flow, this asymmetric convective flow is able to remove the cool gas accumulating at the cluster core and indeed there is a net outflow persisting for time-scales of approximately an order of magnitude longer than the time for which the source is active or longer. The convective flow may also provide a mechanism to enhance the metallicity of the cluster gas at large cluster radii.