CMB reconstruction from the WMAP and Planck PR2 data

TL;DR

This paper presents a new, high-quality CMB map reconstructed from combined WMAP and Planck data using an improved component separation method, demonstrating low foreground contamination and consistency with theoretical models.

Contribution

It introduces an enhanced L-GMCA method for CMB reconstruction, producing a fully reproducible, high-fidelity full-sky CMB map from combined datasets.

Findings

The reconstructed CMB map has low foreground contamination.

The power spectrum matches the Planck PR2 theoretical best-fit.

The method is fully reproducible with provided code.

Abstract

In this article, we describe a new estimate of the Cosmic Microwave Background (CMB) intensity map reconstructed by a joint analysis of the full Planck 2015 data (PR2) and WMAP nine-years. It provides more than a mere update of the CMB map introduced in (Bobin et al. 2014b) since it benefits from an improvement of the component separation method L-GMCA (Local-Generalized Morphological Component Analysis) that allows the efficient separation of correlated components (Bobin et al. 2015). Based on the most recent CMB data, we further confirm previous results (Bobin et al. 2014b) showing that the proposed CMB map estimate exhibits appealing characteristics for astrophysical and cosmological applications: i) it is a full sky map that did not require any inpainting or interpolation post-processing, ii) foreground contamination is showed to be very low even on the galactic center, iii) it does not exhibit any detectable trace of thermal SZ contamination. We show that its power spectrum is in good agreement with the Planck PR2 official theoretical best-fit power spectrum. Finally, following the principle of reproducible research, we provide the codes to reproduce the L-GMCA, which makes it the only reproducible CMB map.