Exactly Azimuthal Pixelizations of the Sky

TL;DR

This paper explores azimuthal pixelizations of the sky that enable efficient spherical transforms, focusing on their impact on CMB power spectrum extraction and advocating for an 'igloo' pixelization for its simplicity and accuracy.

Contribution

It introduces and analyzes azimuthal pixelizations, especially the 'igloo' type, demonstrating their advantages for fast, exact sky simulations and precise correction of pixel smoothing effects.

Findings

Azimuthal pixelizations facilitate fast spherical transforms.

'Igloo' pixelization offers simplicity and accuracy.

Enhanced correction methods improve multipole moment estimation.

Abstract

We investigate various pixelizations of the sky which allow for fast spherical transforms, for implementation in full sky CMB experiments such as Planck and MAP. We study the effect of varying pixel shape and area on the extraction of the CMB power spectrum. We argue for the benefits of having a truly azimuthal, or `igloo' pixelization. Such pixelizations are simple and allow for fast, exact simulations of pixelized skies. They also allow for precise correction to be made which accounts for the effects of pixel smoothing on extracted multipole moments.