ArtDeco: A beam deconvolution code for absolute CMB measurements

TL;DR

ArtDeco is a new beam deconvolution method for CMB measurements that accurately reconstructs sky maps from time-ordered data, accounting for beam shapes and noise, applicable to wide sky surveys.

Contribution

The paper introduces ArtDeco, a beam deconvolution code that processes time-ordered data to produce accurate harmonic coefficients and maps for CMB analysis, independent of scanning strategy.

Findings

Successfully tested with simulations mimicking Planck data.

Effective up to multipole l=1700 with exaggerated beam asymmetry.

Performs well even with white noise presence.

Abstract

We present a method for beam deconvolution for cosmic microwave background (CMB) anisotropy measurements. The code takes as input the time-ordered data, along with the corresponding detector pointings and known beam shapes, and produces as output the harmonic a_Tlm, a_Elm, and a_Blm coefficients of the observed sky. From these one can further construct temperature and Q and U polarisation maps. The method is applicable to absolute CMB measurements with wide sky coverage, and is independent of the scanning strategy. We test the code with extensive simulations, mimicking the resolution and data volume of Planck 30GHz and 70GHz channels, but with exaggerated beam asymmetry. We apply it to multipoles up to l=1700 and examine the results in both pixel space and harmonic space. We also test the method also in presence of white noise.