Planck 2015 results. XVI. Isotropy and statistics of the CMB

P.A.R Ade; N. Aghanim; Y. Akrami; P.K. Aluri; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; A.J. Banday; R.B. Barreiro; N. Bartolo; Per Rex Christensen; Anne Mette Frejsel; Pavel Nasselski; Igor Dmitrievich Novikov; Hans Ulrik Nørgaard-Nielsen

doi:10.1051/0004-6361/201526681

Planck 2015 results. XVI. Isotropy and statistics of the CMB

P.A.R Ade, N. Aghanim, Y. Akrami, P.K. Aluri, M. Arnaud, M. Ashdown, J. Aumont, C. Baccigalupi, A.J. Banday, R.B. Barreiro, N. Bartolo, Per Rex Christensen, Anne Mette Frejsel, Pavel Nasselski, Igor Dmitrievich Novikov, Hans Ulrik Nørgaard-Nielsen

Theoretical high energy, astroparticle and gravitational physics

195 Citations (Scopus)

Abstract

We test the statistical isotropy and Gaussianity of the cosmic microwave background (CMB) anisotropies using observations made by the Planck satellite. Our results are based mainly on the full Planck mission for temperature, but also include some polarization measurements. In particular, we consider the CMB anisotropy maps derived from the multi-frequency Planck data by several component-separation methods. For the temperature anisotropies, we find excellent agreement between results based on these sky maps over both a very large fraction of the sky and a broad range of angular scales, establishing that potential foreground residuals do not affect our studies. Tests of skewness, kurtosis, multi-normality, N-point functions, and Minkowski functionals indicate consistency with Gaussianity, while a power deficit at large angular scales is manifested in several ways, for example low map variance. The results of a peak statistics analysis are consistent with the expectations of a Gaussian random field. The "Cold Spot" is detected with several methods, including map kurtosis, peak statistics, and mean temperature profile. We thoroughly probe the large-scale dipolar power asymmetry, detecting it with several independent tests, and address the subject of a posteriori correction. Tests of directionality suggest the presence of angular clustering from large to small scales, but at a significance that is dependent on the details of the approach. We perform the first examination of polarization data, finding the morphology of stacked peaks to be consistent with the expectations of statistically isotropic simulations. Where they overlap, these results are consistent with the Planck 2013 analysis based on the nominal mission data and provide our most thorough view of the statistics of the CMB fluctuations to date.

Original language	English
Article number	A16
Journal	Astronomy & Astrophysics
Volume	594
ISSN	0004-6361
DOIs	https://doi.org/10.1051/0004-6361/201526681
Publication status	Published - 1 Oct 2016

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Ade, P. A. R., Aghanim, N., Akrami, Y., Aluri, P. K., Arnaud, M., Ashdown, M., Aumont, J., Baccigalupi, C., Banday, A. J., Barreiro, R. B., Bartolo, N., Christensen, P. R., Frejsel, A. M., Nasselski, P., Novikov, I. D., & Nørgaard-Nielsen, H. U. (2016). Planck 2015 results. XVI. Isotropy and statistics of the CMB. Astronomy & Astrophysics, 594, [A16]. https://doi.org/10.1051/0004-6361/201526681

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title = "Planck 2015 results. XVI. Isotropy and statistics of the CMB",

abstract = "We test the statistical isotropy and Gaussianity of the cosmic microwave background (CMB) anisotropies using observations made by the Planck satellite. Our results are based mainly on the full Planck mission for temperature, but also include some polarization measurements. In particular, we consider the CMB anisotropy maps derived from the multi-frequency Planck data by several component-separation methods. For the temperature anisotropies, we find excellent agreement between results based on these sky maps over both a very large fraction of the sky and a broad range of angular scales, establishing that potential foreground residuals do not affect our studies. Tests of skewness, kurtosis, multi-normality, N-point functions, and Minkowski functionals indicate consistency with Gaussianity, while a power deficit at large angular scales is manifested in several ways, for example low map variance. The results of a peak statistics analysis are consistent with the expectations of a Gaussian random field. The {"}Cold Spot{"} is detected with several methods, including map kurtosis, peak statistics, and mean temperature profile. We thoroughly probe the large-scale dipolar power asymmetry, detecting it with several independent tests, and address the subject of a posteriori correction. Tests of directionality suggest the presence of angular clustering from large to small scales, but at a significance that is dependent on the details of the approach. We perform the first examination of polarization data, finding the morphology of stacked peaks to be consistent with the expectations of statistically isotropic simulations. Where they overlap, these results are consistent with the Planck 2013 analysis based on the nominal mission data and provide our most thorough view of the statistics of the CMB fluctuations to date.",

author = "P.A.R Ade and N. Aghanim and Y. Akrami and P.K. Aluri and M. Arnaud and M. Ashdown and J. Aumont and C. Baccigalupi and A.J. Banday and R.B. Barreiro and N. Bartolo and Christensen, {Per Rex} and Frejsel, {Anne Mette} and Pavel Nasselski and Novikov, {Igor Dmitrievich} and N{\o}rgaard-Nielsen, {Hans Ulrik}",

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T1 - Planck 2015 results. XVI. Isotropy and statistics of the CMB

AU - Ade, P.A.R

AU - Aghanim, N.

AU - Akrami, Y.

AU - Aluri, P.K.

AU - Arnaud, M.

AU - Ashdown, M.

AU - Aumont, J.

AU - Baccigalupi, C.

AU - Banday, A.J.

AU - Barreiro, R.B.

AU - Bartolo, N.

AU - Christensen, Per Rex

AU - Frejsel, Anne Mette

AU - Nasselski, Pavel

AU - Novikov, Igor Dmitrievich

AU - Nørgaard-Nielsen, Hans Ulrik

PY - 2016/10/1

Y1 - 2016/10/1

N2 - We test the statistical isotropy and Gaussianity of the cosmic microwave background (CMB) anisotropies using observations made by the Planck satellite. Our results are based mainly on the full Planck mission for temperature, but also include some polarization measurements. In particular, we consider the CMB anisotropy maps derived from the multi-frequency Planck data by several component-separation methods. For the temperature anisotropies, we find excellent agreement between results based on these sky maps over both a very large fraction of the sky and a broad range of angular scales, establishing that potential foreground residuals do not affect our studies. Tests of skewness, kurtosis, multi-normality, N-point functions, and Minkowski functionals indicate consistency with Gaussianity, while a power deficit at large angular scales is manifested in several ways, for example low map variance. The results of a peak statistics analysis are consistent with the expectations of a Gaussian random field. The "Cold Spot" is detected with several methods, including map kurtosis, peak statistics, and mean temperature profile. We thoroughly probe the large-scale dipolar power asymmetry, detecting it with several independent tests, and address the subject of a posteriori correction. Tests of directionality suggest the presence of angular clustering from large to small scales, but at a significance that is dependent on the details of the approach. We perform the first examination of polarization data, finding the morphology of stacked peaks to be consistent with the expectations of statistically isotropic simulations. Where they overlap, these results are consistent with the Planck 2013 analysis based on the nominal mission data and provide our most thorough view of the statistics of the CMB fluctuations to date.

AB - We test the statistical isotropy and Gaussianity of the cosmic microwave background (CMB) anisotropies using observations made by the Planck satellite. Our results are based mainly on the full Planck mission for temperature, but also include some polarization measurements. In particular, we consider the CMB anisotropy maps derived from the multi-frequency Planck data by several component-separation methods. For the temperature anisotropies, we find excellent agreement between results based on these sky maps over both a very large fraction of the sky and a broad range of angular scales, establishing that potential foreground residuals do not affect our studies. Tests of skewness, kurtosis, multi-normality, N-point functions, and Minkowski functionals indicate consistency with Gaussianity, while a power deficit at large angular scales is manifested in several ways, for example low map variance. The results of a peak statistics analysis are consistent with the expectations of a Gaussian random field. The "Cold Spot" is detected with several methods, including map kurtosis, peak statistics, and mean temperature profile. We thoroughly probe the large-scale dipolar power asymmetry, detecting it with several independent tests, and address the subject of a posteriori correction. Tests of directionality suggest the presence of angular clustering from large to small scales, but at a significance that is dependent on the details of the approach. We perform the first examination of polarization data, finding the morphology of stacked peaks to be consistent with the expectations of statistically isotropic simulations. Where they overlap, these results are consistent with the Planck 2013 analysis based on the nominal mission data and provide our most thorough view of the statistics of the CMB fluctuations to date.

U2 - 10.1051/0004-6361/201526681

DO - 10.1051/0004-6361/201526681

M3 - Journal article

SN - 0004-6361

VL - 594

JO - Astronomy and Astrophysics Supplement Series

JF - Astronomy and Astrophysics Supplement Series

M1 - A16

ER -

Planck 2015 results. XVI. Isotropy and statistics of the CMB

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