Searching for non-Gaussianity in the Planck data

TL;DR

This paper investigates the non-Gaussian features in Planck CMB data using kurtosis and skewness analysis, finding that foreground cleaning and masking significantly influence the detection of Gaussianity deviations.

Contribution

It extends previous non-Gaussianity analysis methods to Planck data, demonstrating the impact of masking on statistical results.

Findings

Significant non-Gaussian deviations with less severe masks.

Consistency with Gaussianity when using the union mask U73.

Foreground cleaning affects non-Gaussianity detection.

Abstract

The statistical properties of the temperature anisotropies and polarization of the of cosmic microwave background (CMB) radiation offer a powerful probe of the physics of the early universe. In recent works a statistical procedure based upon the calculation of the kurtosis and skewness of the data in patches of CMB sky-sphere has been proposed and used to investigate the large-angle deviation from Gaussianity in WMAP maps. Here we briefly address the question as to how this analysis of Gaussianity is modified if the foreground-cleaned Planck maps are considered. We show that although the foreground-cleaned Planck maps present significant deviation from Gaussianity of different degrees when a less severe mask is used, they become consistent with Gaussianity, as detected by our indicators, when masked with the union mask U73.