Lensing-induced cluster signatures in the cosmic microwave background

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 mu K(sigma(v)/1400 km s(-1))(2), where sigma(v) is the velocity dispersion of the cluster, and several mu K 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.