A test for transverse motions of clusters of galaxies
A test for transverse motions of clusters of galaxies
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DOI：
10.1038/302315a0
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发表时间：
1983-03
期刊：
影响因子：
64.8
通讯作者：
M. Birkinshaw;S. Gull
中科院分区：
文献类型：
--
作者：
M. Birkinshaw;S. Gull
虽然静止的透镜不会改变各向同性辐射场的亮度，但移动的透镜会产生特征性的双侧亮度图案，该图案可用于推断透镜的横向速度。这种效应的大小与横向速度和透镜的强度成正比。我们认为，这种效应提供了一种方法来测量星系团的横向速度，在这种情况下，透镜是引力和辐射场是各向同性的微波背景。这种效应的预测幅度是在目前的观测灵敏度极限，但至少是大的原始背景波动的预期水平。
Although a static lens can produce no change in the brightness of an isotropic radiation field, a moving lens produces a characteristic two-sided brightness pattern that may be used to deduce the transverse velocity of the lens. The magnitude of the effect is proportional to both the transverse velocity and the strength of the lens. We suggest here that this effect provides a method for measuring the transverse velocities of clusters of galaxies; in this case the lens is gravitational and the radiation field is the isotropic microwave background. The predicted magnitude of this effect is at the present sensitivity limits of observation but is at least as large as the expected level of primordial background fluctuations.