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Title: POWER ASYMMETRY IN WMAP AND PLANCK TEMPERATURE SKY MAPS AS MEASURED BY A LOCAL VARIANCE ESTIMATOR

We revisit the question of hemispherical power asymmetry in the WMAP and Planck temperature sky maps by measuring the local variance over the sky and on disks of various sizes. For the 2013 Planck sky map we find that none of the 1000 available isotropic Planck ''Full Focal Plane'' simulations have a larger variance asymmetry than that estimated from the data, suggesting the presence of an anisotropic signature formally significant at least at the 3.3σ level. For the WMAP 9 year data we find that 5 out of 1000 simulations have a larger asymmetry. The preferred direction for the asymmetry from the Planck data is (l, b) = (212°, –13°), in good agreement with previous reports of the same hemispherical power asymmetry.
Authors:
; ; ;  [1] ;  [2] ;  [3] ;  [4]
  1. Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway)
  2. Asia Pacific Center for Theoretical Physics, Pohang, Gyeongbuk 790-784 (Korea, Republic of)
  3. Université de Toulouse, UPS-OMP, IRAP, F-31028 Toulouse cedex 4 (France)
  4. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA (United States)
Publication Date:
OSTI Identifier:
22365922
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 784; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANISOTROPY; ASYMMETRY; BACKGROUND RADIATION; COMPUTERIZED SIMULATION; COSMOLOGY