Lensing-induced Cluster Signatures in the Cosmic Microwave Background
Lensing-induced Cluster Signatures in the Cosmic Microwave Background
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DOI：
10.1086/309098
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发表时间：
1999-07
期刊：
影响因子：
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通讯作者：
U. Seljak;M. Zaldarriaga
中科院分区：
文献类型：
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作者：
U. Seljak;M. Zaldarriaga
我们证明星系团会在宇宙微波背景（CMB）顶部引起阶梯状摆动。摆动的方向与 CMB 的大尺度梯度平行，从而可以将影响与其他小尺度波动隔离开来。该效应对偏转角而不是其导数（剪切或放大）敏感，因此比其他方法具有更高的灵敏度来追踪星团的外部部分。该效应的典型幅度为 10 μK(σv/1400 km s-1 )2，其中 σv 是星团的速度色散，并且几个 μK 信号会延伸到几分之一度。我们推导了几个简单参数化集群模型的温度分布表达式，并识别了参数之间的一些简并性。最后，我们讨论如何使用定制设计的滤波器将该信号与 CMB 上的其他印记分开。下一代小型宇宙微波背景望远镜可以探测到这种效应，并可以提供有关超出维里半径的星团密度分布的信息。
We show that clusters of galaxies induce steplike wiggles on top of the cosmic microwave background (CMB). The direction of the wiggle is parallel to the large-scale gradient of the CMB, allowing one to isolate the effect from other small-scale fluctuations. The effect is sensitive to the deflection angle rather than its derivative (shear or magnification) and thus traces outer parts of the cluster with higher sensitivity than some other methods. A typical amplitude of the effect is 10 μK(σv/1400 km s-1 )2, where σv is the velocity dispersion of the cluster, and several μK signals extend out to a fraction of a degree. We derive the expressions for the temperature profile for several simple parameterized cluster models and identify some degeneracies between parameters. Finally, we discuss how to separate this signal from other imprints on the CMB using custom-designed filters. Detection of this effect is within reach of the next generation of small-scale CMB telescopes and could provide information about the cluster density profile beyond the virial radius.