Cosmic shear with one component and its application to future radio surveys

TL;DR

The paper introduces a simplified one-component Kinematic Lensing method for cosmic shear measurement, which reduces noise and observational effort, and discusses its potential advantages for future radio and spectroscopic surveys.

Contribution

It proposes a new, less resource-intensive one-component KL technique for cosmic shear analysis and evaluates its performance for future radio and spectroscopic surveys.

Findings

One-component KL reduces shape noise compared to traditional methods.

Current radio surveys are not yet competitive with WL using this method.

Deeper spectroscopic surveys could enable the one-component KL to outperform WL.

Abstract

We present a new approach to measuring cosmic shear: the one-component Kinematic Lensing (KL) method. This technique provides a simplified implementation of KL that reduces shape noise in weak lensing (WL) by combining kinematic information with imaging data, while requiring less observational effort than the full two-component KL. We perform simulated likelihood analyses to assess the performance of the one-component KL and demonstrate its applicability to future radio surveys. Our forecasts indicate that, for radio surveys, the one-component KL is not yet competitive with traditional WL due to the shallow redshift distribution of HI-selected galaxies. However, when applying this method to deeper spectroscopic surveys with stronger emission lines, the one-component KL approach could surpass WL in constraining power, offering a promising and efficient pathway for future shear analyses.