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Related papers: Detection of a non-Gaussian Spot in WMAP

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We constrain the primordial non-Gaussianity parameter of the local model f_{NL} using the skewness power spectrum associated with the two-to-one cumulant correlator of cosmic microwave background temperature anisotropies. This…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-22 Joseph Smidt , Alexandre Amblard , Paolo Serra , Asantha Cooray

The structure of the cold spot, of a non-Gaussian anomaly in the cosmic microwave background (CMB) sky first detected by Vielva et al. is studied using the data by Planck satellite. The obtained map of the degree of stochasticity (K-map) of…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-24 V. G. Gurzadyan , A. L. Kashin , H. Khachatryan , E. Poghosian , S. Sargsyan , G. Yegorian

We investigate the performance of spherical wavelets in discriminating between standard inflationary models (Gaussian) and non-Gaussian models. For the later we consider small perturbations of the Gaussian model in which an artificially…

Astrophysics · Physics 2009-11-07 E. Martinez-Gonzalez , J. E. Gallegos , F. Argueso , L. Cayon , J. L. Sanz

We present non-Gaussianity testing on recently-released derived maps from the first-year WMAP data by Tegmark, de Oliveria-Costa and Hamilton. Our test is based on a phase mapping technique which has the advantage of testing non-Gaussianity…

Astrophysics · Physics 2009-11-07 Lung-Yih Chiang , Pavel D. Naselsky , Oleg V. Verkhodanov , Michael J. Way

We present a new method based on the N-point probability distribution (pdf) to study non-Gaussianity in cosmic microwave background (CMB) maps. Likelihood and Bayesian estimation are applied to a local non-linear perturbed model up to third…

Astrophysics · Physics 2015-05-13 P. Vielva , J. L. Sanz

[Abridged] In recent works we have proposed two new large-angle non-Gaussianity indicators based on skewness and kurtosis of patches of CMB sky-sphere, and used them to find out significant deviation from Gaussianity in frequency bands and…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-15 A. Bernui , M. J. Reboucas

Observational cosmology is entering an era in which high precision will be required in both measurement and data analysis. Accuracy, however, can only be achieved with a thorough understanding of potential sources of contamination from…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-19 Assaf Ben-David , Sebastian von Hausegger , Andrew D. Jackson

The statistical properties of the temperature anisotropies and polarization of the of cosmic microwave background (CMB) radiation offer a powerful probe of the physics of the early universe. In recent works a statistical procedure based…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 M. J. Reboucas , A. Bernui

We present limits to the amplitude of non-Gaussian primordial fluctuations in the WMAP 1-year cosmic microwave background sky maps. A non-linear coupling parameter, f_NL, characterizes the amplitude of a quadratic term in the primordial…

A detection or nondetection of primordial non-Gaussianity in the CMB data is essential not only to test alternative models of the physics of the early universe but also to discriminate among classes of inflationary models. Given this far…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-15 A. Bernui , M. J. Reboucas

We report the results of an extragalactic point source search using the 61 and 94 GHz (V- and W-band) temperature maps from the Wilkinson Microwave Anisotropy Probe (WMAP). Applying a method that cancels the ``noise'' due to the CMB…

Astrophysics · Physics 2009-11-13 Xi Chen , Edward L. Wright

We present the results of an extragalactic point source search using the five-year WMAP 41, 61 and 94 GHz (Q-, V- and W-band) temperature maps. This work is an extension of our point source search in the WMAP maps applying a CMB-free…

Astrophysics · Physics 2011-02-11 Xi Chen , Edward L. Wright

We present a Gaussianity analysis of the WMAP 5-year Cosmic Microwave Background (CMB) temperature anisotropy data maps. We use several third order estimators based on the spherical Mexican hat wavelet. We impose constraints on the local…

The non-Gaussian cold spot found in the WMAP data has created controversy about its origin. Here we calculate the Bayesian posterior probability ratios for three different models that could explain the cold spot. A recent work claimed that…

Astrophysics · Physics 2009-11-13 M. Cruz , E. Martinez-Gonzalez , P. Vielva , J. M. Diego , M. Hobson , N. Turok

The detection of non-Gaussianity in the CMB data would rule out a number of inflationary models. A null detection of non-Gaussianity, instead, would exclude alternative models for the early universe. Thus, a detection or non-detection of…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-15 A. Bernui , M. J. Rebouças , A. F. F. Teixeira

The cosmic microwave background (CMB) has non-Gaussian features in the temperature fluctuations. An anomalous cold spot surrounded with a hot ring, called the Cold Spot is one of such features. If a large underdence region (supervoid)…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-14 Yuichi Higuchi , Kaiki Taro Inoue

We have used the MHW2 filter to obtain estimates of the flux densities at the WMAP frequencies of a complete sample of 2491 sources, mostly brighter than 500 mJy at 5 GHz, distributed over the whole sky excluding a strip around the Galactic…

ABRIDGED: We introduce and analyze a method for testing statistical isotropy and Gaussianity and apply it to the WMAP CMB foreground reduced, temperature maps, and cross-channel difference maps. We divide the sky into regions of varying…

Astrophysics · Physics 2009-06-23 Bartosz Lew

By cross-correlating templates constructed from the 2 Micron All Sky Survey (2MASS) Extended Source (XSC) catalogue with WMAP's first year data, we search for the thermal Sunyaev-Zel'dovich signature induced by hot gas in the local…

Astrophysics · Physics 2009-11-10 C. Hernandez-Monteagudo , R. Genova-Santos , F. Atrio-Barandela

A remarkable similarity between the large-scale non-Gaussian pattern of cosmic microwave background (CMB) temperatures obtained by Wilkinson Microwave Anisotropy Probe (WMAP) mission and the distribution feature of observation numbers is…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-01 Ti-Pei Li , Hao Liu , Li-Ming Song , Shao-Lin Xiong , Jian-Yin Nie