Power asymmetry in WMAP and Planck temperature sky maps as measured by a local variance estimator

Abstract

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 $3.3\sigma$ 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 $(l,b)=(212^{\circ },-13^{\circ })$, in good agreement with previous reports of the same hemispherical power asymmetry.

7 pages, 3 figures; text added in response to referee's comments; matches version published in ApJL

References in corpus (13)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Temperature Analysis
• Hemispherical power asymmetry in the three-year Wilkinson Microwave Anisotropy Probe sky maps
• The Uncorrelated Universe: Statistical Anisotropy and the Vanishing Angular Correlation Function in WMAP Years 1-3
• The non-Gaussian Cold Spot in the 3-year WMAP data
• The Axis of Evil revisited
• Bianchi Type VII_h Models and the WMAP 3-year Data
• Testing Global Isotropy of Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Data: Temperature Analysis
• Needlet Detection of Features in WMAP CMB Sky and the Impact on Anisotropies and Hemispherical Asymmetries
• Markov chain Monte Carlo analysis of Bianchi VII_h models
• Crossing Statistic: Reconstructing the Expansion History of the Universe
• Can a primordial magnetic field originate large-scale anomalies in WMAP data?
• Real space tests of the statistical isotropy and Gaussianity of the WMAP CMB data

Cited by in corpus (38)

• Probing cosmic isotropy with a new X-ray galaxy cluster sample through the $L_{\text{X}}-T$ scaling relation
• Homogeneity and isotropy in the 2MASS Photometric Redshift catalogue
• Probing the anisotropic expansion from supernovae and GRBs in a model-independent way
• On the significance of power asymmetries in Planck CMB data at all scales
• Anisotropy of the Universe via the Pantheon supernovae sample revisited
• Anisotropy in the all-sky distribution of galaxy morphological types
• Testing Isotropy in the Local Universe
• Testing Isotropic Universe Using the Gamma-Ray Burst Data of Fermi / GBM
• Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies
• Inflationary power asymmetry from primordial domain walls
• CMB Hemispherical Asymmetry: Long Mode Modulation and non-Gaussianity
• Polypolar spherical harmonic decomposition of galaxy correlators in redshift space: Toward testing cosmic rotational symmetry
• Local variance asymmetries in Planck temperature anisotropy maps
• Hemispherical Power Asymmetry from a Space-Dependent Component of the Adiabatic Power Spectrum
• CMB Anisotropies from a Gradient Mode
• Expected dipole asymmetry in CMB polarization
• North-South non-Gaussian asymmetry in PLANCK CMB maps
• A separate universe view of the asymmetric sky
• Generating the cosmic microwave background power asymmetry with $g_{NL}$
• Asymmetry in the reconstructed deceleration parameter
• CMB hemispherical asymmetry from non-linear isocurvature perturbations
• The Kullback-Leibler Divergence as an Estimator of the Statistical Properties of CMB Maps
• Generating $\fnl$ at $\ell\lsim 60$
• CMB low multipole alignments in the $\mathbf{\Lambda }$CDM and Dipolar models
• Linking the BICEP2 result and the hemispherical power asymmetry through spatial variation of $r$
• Negative Running of the Spectral Index, Hemispherical Asymmetry and the Consistency of Planck with Large $r$
• Scale-dependent hemispherical asymmetry from general initial state during inflation
• Hemispherical asymmetry from an isotropy violating stochastic gravitational wave background
• SNe Ia Tests of Quintessence Tracker Cosmology in an Anisotropic Background
• Fingerprints of Anomalous Primordial Universe on the Abundance of Large Scale Structures
• Asymmetry of the CMB map: local and global anomalies
• The Initial State of a Primordial Anisotropic Stage of Inflation
• Finslerian dipolar modulation of the CMB power spectra at scales $2<l<600$
• A forecast for the detection of the power asymmetry from galaxy surveys
• Long gradient mode and large-scale structure observables
• Testing cosmological models with large-scale power modulation using microwave background polarization observations
• CMB Polarization by the Asymmetric Template of Scalar Perturbations
• A Test for the Zero Mean Hypothesis in Cosmology