Asymmetric beams and CMB statistical anisotropy

Journal Article · Sat May 15 04:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.103003· OSTI ID:21415184

Hanson, Duncan ^[1]; Lewis, Antony ^[1]; Challinor, Anthony ^[1]

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1. Institute of Astronomy and Kavli Institute for Cosmology Cambridge, University of Cambridge, Madingley Road, Cambridge CB3 OHA (United Kingdom)

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.

• OSTI ID: 21415184
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 10 Vol. 81; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANISOTROPY
ASYMMETRY
BEAMS
ELECTROMAGNETIC RADIATION
MICROWAVE RADIATION
MODULATION
RADIATIONS
RELICT RADIATION
SPECTRA