Needatool: A Needlet Analysis Tool for Cosmological Data Processing

TL;DR

NeedATool is a software that utilizes needlets, a type of wavelet, to enhance the analysis of cosmological data on the sphere, especially for cosmic microwave background studies, combining advantages of real and harmonic space methods.

Contribution

This paper introduces NeedATool, a new software tool based on needlets, improving the analysis of spherical cosmological data by leveraging their localization properties.

Findings

NeedATool effectively analyzes CMB data with partial sky coverage.

Needlets enable better noise handling and beam treatment.

The tool combines advantages of real and harmonic space analyses.

Abstract

We introduce NeedATool (Needlet Analysis Tool), a software for data analysis based on needlets, a wavelet rendition which is powerful for the analysis of fields defined on a sphere. Needlets have been applied successfully to the treatment of astrophysical and cosmological observations, and in particular to the analysis of cosmic microwave background (CMB) data. Usually, such analyses are performed in real space as well as in its dual domain, the harmonic one. Both spaces have advantages and disadvantages: for example, in pixel space it is easier to deal with partial sky coverage and experimental noise; in harmonic domain, beam treatment and comparison with theoretical predictions are more effective. During the last decade, however, wavelets have emerged as a useful tool for CMB data analysis, since they allow to combine most of the advantages of the two spaces, one of the main reasons being their sharp localisation. In this paper, we outline the analytical properties of needlets and discuss the main features of the numerical code, which should be a valuable addition to the CMB analyst's toolbox.