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(σ_v/1400 km s~(-1)), where σ_v 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.
展开▼
机译：我们显示，星系团在宇宙微波背景（CMB）的顶部诱发阶梯状摆动。摆动的方向与CMB的大比例梯度平行，从而可以将效果与其他小范围的波动隔离开。该效果对偏转角敏感，而不是其导数（剪切或放大），因此与其他方法相比，以更高的灵敏度跟踪群集的外部。效应的典型幅度为10μK（σ_v/ 1400 km s〜（-1）），其中σ_v是簇的速度色散，几个μK信号延伸出一度的分数。我们导出了几个简单的参数化聚类模型的温度曲线表达式，并确定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过滤器将此信号与CMB上的其他标记分开。这种影响的检测是下一代小型CMB望远镜所能达到的，并且可以提供有关超出病毒半径的簇密度分布的信息。
展开▼
