AtLAST -- Determination of Halo Mass Density Profiles at kpc Scales through Magnification Bias

TL;DR

This paper discusses using magnification bias from lensing to measure galaxy and cluster mass profiles at kpc scales, emphasizing the need for advanced submillimetre surveys with facilities like AtLAST.

Contribution

It highlights the potential of magnification bias as a precise, shape-independent method for probing small-scale mass density profiles, enabled by next-generation submm telescopes.

Findings

Magnification bias can effectively probe mass profiles at kpc scales.

Current limitations hinder the full potential of this technique.

Next-generation telescopes like AtLAST are essential for progress.

Abstract

Magnification bias, the lensing-induced modification of background source number counts, provides a uniquely powerful probe of the mass density profiles of galaxies and clusters down to kpc scales. Unlike shear-based weak lensing, magnification bias does not rely on galaxy shapes and thus avoids dominant small-scale systematics. Existing studies, however, are limited by sky coverage, positional uncertainty, and insufficiently deep, confusion-limited submillimetre (submm) surveys. A next-generation wide-field, high-throughput submm facility like the proposed 50m-telescope AtLAST is required to unlock this technique's full diagnostic power.