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Related papers: Local properties of WMAP Cold Spot

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It is possible to classify pixels of a smoothed cosmic microwave background (CMB) fluctuation map according to their local curvature in ``hill'', ``lake'' and ``saddle'' regions. In the Gaussian case, fractional areas occupied by pixels of…

Astrophysics · Physics 2011-05-10 O. Doré , S. Colombi , F. R. Bouchet

We continue the analysis of non-Gaussianities in the CMB by means of the scaling index method (SIM, Raeth, Schuecker & Banday 2007) by applying this method on the 5-year WMAP data. We compare each of the results with 1000 Monte Carlo…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-14 G. Rossmanith , C. Raeth , A. J. Banday , G. Morfill

Using the 5 year WMAP data, we re-investigate claims of non-Gaussianities and asymmetries detected in local curvature statistics of the 1 year WMAP data. In Hansen et al 2004, it was found that the northern ecliptic hemisphere was…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Øystein Rudjord , Nicolaas E. Groeneboom , Frode K. Hansen , Paolo Cabella

We present measurements of the clustering of hot and cold patches in the microwave background sky as measured from the Wilkinson Microwave Anisotropy Probe (WMAP) five-year data. These measurements are compared with theoretical predictions…

Cosmology and Nongalactic Astrophysics · Physics 2009-06-12 Graziano Rossi , Ravi K. Sheth , Changbom Park , Carlos Hernandez-Monteagudo

We introduce the numbers of hot and cold spots, $n_h$ and $n_c$, of excursion sets of the CMB temperature anisotropy maps as statistical observables that can discriminate different non-Gaussian models. We numerically compute them from…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Pravabati Chingangbam , Changbom Park , K. P. Yogendran , Rien van de Weygaert

The extraction of cosmological parameters from microwave background observations relies on specific assumptions about the statistical properties of the data, in particular that the p-point distributions of temperature fluctuations are…

Astrophysics · Physics 2007-05-23 Patrick Dineen , Peter Coles

We study the statistical properties of the 1st year WMAP data on different scales using the spherical mexican hat wavelet transform. Consistent with the results of Vielva et al. (2003) we find a deviation from Gaussianity in the form of…

Astrophysics · Physics 2008-11-26 Pia Mukherjee , Yun Wang

Some analyses of recent cosmic microwave background (CMB) data have provided hints that there are deviations from Gaussianity in the WMAP CMB temperature fluctuations. Given the far reaching consequences of such a non-Gaussianity for our…

Astrophysics · Physics 2009-03-31 A. Bernui , M. J. Reboucas

In the present work, we study the largest structures of the CMB temperature measured by Planck in terms of the most prominent peaks on the sky, which, in particular, are located in the southern galactic hemisphere. Besides these large-scale…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-17 A. Marcos-Caballero , E. Martínez-González , P. Vielva

The non-Gaussian Cold Spot (CS) surrounded by its hot ring is one of the most striking features of the CMB. It has been speculated that either new physics or ISW effect induced by the presence of a cosmic void at high redshift can account…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-19 Diego Garcia Lambas , Frode K. Hansen , Facundo Toscano , Heliana E. Luparello , Ezequiel F. Boero

[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

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 present a search for non-Gaussianity in the WMAP first-year data using the two-point correlation function of maxima and minima in the temperature map. We find evidence for non-Gaussianity on large scales, whose origin appears to be…

Astrophysics · Physics 2009-11-13 R. Tojeiro , P. G. Castro , A. F. Heavens , S. Gupta

The recent study of BOOMERanG 150 GHz Cosmic Microwave Background (CMB) radiation maps have detected ellipticity of the temperature anisotropy spots independent on the temperature threshold. The effect has been found for spots up to several…

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

We present results from a test for the Gaussianity of the whole sky sub-degree scale CMB temperature anisotropy measured by the Wilkinson Microwave Anisotropy Probe (WMAP). We calculate the genus from the foreground-subtracted and…

Astrophysics · Physics 2010-04-06 Chan-Gyung Park

Recent results of the ESA Planck satellite have confirmed the existence of some anomalies in the statistical distribution of the cosmic microwave background (CMB) anisotropies. One of the most intriguing anomalies is the Cold Spot, firstly…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 R. Fernández-Cobos , P. Vielva , E. Martínez-González , M. Tucci , M. Cruz

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

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

We present skeleton studies of non-Gaussianity in the CMB temperature anisotropy observed in the WMAP5 data. The local skeleton is traced on the 2D sphere by cubic spline interpolation which leads to more accurate estimation of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Zhen Hou , A. J. Banday , Krzysztof M. Gorski , Franz Elsner , Benjamin D. Wandelt