Cluster Mergers, Core Oscillations, and Cold Fronts
Cluster Mergers, Core Oscillations, and Cold Fronts
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集群合并、核心振荡和冷锋
DOI：
10.1086/425952
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
M. Henriksen
中科院分区：
文献类型：
--
作者：
E. Tittley;M. Henriksen
我们使用流体力学数值模拟来证明星系团中的一类冷锋可以归因于暗物质分布的振荡。振荡是由低质量子结构的离轴通道引起的。从模拟中，我们得出了三个可观察到的表明振荡的形态学特征：(1)压缩同卵团的存在，(2)压缩区域必须是交替的（相反的和交错的），并且位于穿过簇中心的轴上，(3)每个压缩区域的梯度必须穿过簇中心。在文献中报道的六个簇中有四个具有与振荡存在一致的冷锋形态。振荡的星团分别是A496、A1795、A2142和RX J1720.1+2638。星系团A2256和A3667并不一致，所以冷锋被解释为星系团的残余物。振荡可能能够提供足够的能量来解决冷却流问题，重要的是，在一个延长的持续时间内提供能量。
We use numerical simulations with hydrodynamics to demonstrate that a class of cold fronts in galaxy clusters can be attributed to oscillations of the dark matter distribution. The oscillations are initiated by the off-axis passage of a low-mass substructure. From the simulations, we derive three observable morphological features indicative of oscillations: (1) the existence of compressed isophotes, (2) the regions of compression must be alternate (opposite and staggered) and lie on an axis passing through the center of the cluster, and (3) the gradient of each compression region must pass through the center of the cluster. Four of six clusters reported in the literature have cold front morphologies consistent with the presence of oscillations. The clusters with oscillations are A496, A1795, A2142, and RX J1720.1+2638. Galaxy clusters A2256 and A3667 are not consistent, so the cold fronts are interpreted as group remnants. The oscillations may be able to provide sufficient energy to solve the cooling flow problem and, importantly, provide it over an extended duration.