Full-sky CMB lensing reconstruction in presence of sky-cuts

TL;DR

This paper presents a method for reconstructing the full-sky CMB lensing potential and its power spectrum, effectively handling sky-cuts caused by point sources and Galactic contamination, ensuring unbiased results.

Contribution

The paper introduces a technique that separately addresses point source masking and Galactic plane masking, using Gaussian constrained realizations and apodized masks for unbiased lensing reconstruction.

Findings

Accurate reconstruction of the lensing potential power spectrum despite sky-cuts.

No significant bias introduced by the proposed masking and filling methods.

Effective separation of point source and Galactic contamination effects.

Abstract

We consider the reconstruction of the CMB lensing potential and its power spectrum of the full sphere in presence of sky-cuts due to point sources and Galactic contaminations. Those two effects are treated separately. Small regions contaminated by point sources are filled in using Gaussian constrained realizations. The Galactic plane is simply masked using an apodized mask before lensing reconstruction. This algorithm recovers the power spectrum of the lensing potential with no significant bias.