Asymmetric Beams and CMB Statistical Anisotropy
Cosmology and Nongalactic Astrophysics
2010-10-05 v2
Abstract
Beam asymmetries result in statistically-anisotropic cosmic microwave background (CMB) maps. Typically, they are studied for their effects on the CMB power spectrum, however they more closely mimic anisotropic effects such as gravitational lensing and primordial power asymmetry. We discuss tools for studying the effects of beam asymmetry on general quadratic estimators of anisotropy, analytically for full-sky observations as well as in the analysis of realistic data. We demonstrate this methodology in application to a recently-detected 9 sigma quadrupolar modulation effect in the WMAP data, showing that beams provide a complete and sufficient explanation for the anomaly.
Keywords
Cite
@article{arxiv.1003.0198,
title = {Asymmetric Beams and CMB Statistical Anisotropy},
author = {Duncan Hanson and Antony Lewis and Anthony Challinor},
journal= {arXiv preprint arXiv:1003.0198},
year = {2010}
}
Comments
updated to match PRD version + typo correction in Eq. B3