Phase analysis of the cosmic microwave background from an incomplete sky coverage

TL;DR

This paper introduces a new method for analyzing the phases of the cosmic microwave background on incomplete sky maps, enabling detection of non-Gaussian features and anisotropies without full-sky data.

Contribution

A novel phase analysis technique using Fourier phases of equal-latitude pixel rings for incomplete sky coverage in CMB studies.

Findings

Allows analysis of non-Gaussian features in partial sky data

Enables localization of anisotropies and departures from isotropy

Provides a tool for probing regions contaminated by Galactic emissions

Abstract

Phases of the spherical harmonic analysis of full-sky cosmic microwave background (CMB) temperature data contain useful information complementary to the ubiquitous angular power spectrum. In this letter we present a new method of phase analysis on incomplete sky maps. It is based on Fourier phases of equal-latitude pixel rings of the map, which are related to the mean angle of the trigonometric moments from the full-sky phases. They have an advantage for probing regions of interest without tapping polluted Galactic plane area, and can localize non-Gaussian features and departure from statistical isotropy in the CMB.