The Moving Lens Effect: Simulations, Forecasts and Foreground Mitigation

TL;DR

This paper explores the moving lens effect caused by massive objects' peculiar motion, proposing a new detection method, forecasting its observability with future surveys, and introducing a foreground mitigation strategy.

Contribution

It introduces a stacking estimator for detecting the moving lens effect, validated with simulations, and forecasts its detectability in upcoming surveys.

Findings

Forecasts high-significance detections with future surveys.

Proposes a new foreground mitigation strategy.

Validates the estimator using simulations.

Abstract

The peculiar motion of massive objects across the line of sight imprints a dipolar temperature anisotropy pattern on the cosmic microwave background known as the moving lens effect. This effect provides a unique probe of the transverse components of the peculiar velocity field, but has not yet been detected due to its small size. We implement and validate a stacking estimator for the moving lens signal using a galaxy catalog as a tracer of massive haloes combined with reconstructed velocities from the galaxy number density field. Using simulations, we forecast detection prospects for the moving lens signal from current and upcoming microwave background and galaxy surveys. We demonstrate a new foreground mitigation strategy likely sufficient for current data sets, and discuss various sources of systematic error and noise. Upcoming galaxy surveys will provide high significance statistical detections of the moving lens effect.