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Related papers: Wiener Filtering of the COBE DMR Data

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Fourier analysis and power spectrum estimation of the cosmic microwave background anisotropy on an incompletely sampled sky developed by Gorski (1994) has been applied to the high-latitude portion of the 4-year COBE DMR 31.5, 53 and 90 GHz…

Astrophysics · Physics 2009-10-28 K. M. Gorski , A. J. Banday , C. L. Bennett , G. Hinshaw , A. Kogut , G. F. Smoot , E. L. Wright

Two recent papers have claimed detection of non-Gaussian features in the COBE DMR sky maps of the cosmic microwave background. We confirm these results, but argue that Gaussianity is still not convincingly ruled out. Since a score of…

Astrophysics · Physics 2009-10-31 Benjamin C. Bromley , Max Tegmark

We use the two-point correlation function of the extrema points (peaks and valleys) in the COBE Differential Microwave Radiometers (DMR) 2-year sky maps as a test for non-Gaussian temperature distribution in the cosmic microwave background…

Astrophysics · Physics 2011-05-10 A. Kogut , A. J. Banday , C. L. Bennett , G. Hinshaw , P. M. Lubin , G. F. Smoot

We describe an algorithm for the extraction of the angular power spectrum of an intensity field, such as the cosmic microwave background (CMB), from interferometer data. This new method, based on the gridding of interferometer visibilities…

Large patterns could exist on the microwave sky as a result of various non-standard possibilities for the large-scale Universe -- rotation or shear, non-trivial topology, and single topological defects are specific examples. All-sky (or…

Astrophysics · Physics 2009-10-31 Emory F. Bunn , Douglas Scott

We have simulated full-sky maps of the Cosmic Microwave Background (CMB) anisotropy expected from Cold Dark Matter (CDM) models at 0.5 and 1.0 degree angular resolution. Statistical properties of the maps are presented as a function of sky…

Astrophysics · Physics 2007-05-23 G. Hinshaw , C. L. Bennett , A. Kogut

We use the COBE Differential Microwave Radiometers (DMR) 4-year sky maps to model Galactic microwave emission at high latitudes (|b| > 20 deg). Cross-correlation of the DMR maps with Galactic template maps detects fluctuations in the…

Astrophysics · Physics 2009-10-28 A. Kogut , G. Hinshaw , A. J. Banday , C. L. Bennett , K. Gorski , G. F. Smoot , E. L. Wright

Removal of systematic effects is crucial in present and future CMB experiments mapping large fraction of the sky. Accurate CMB measurements ask for multi-feed array instruments observing the sky with a redundant scanning strategy covering…

Astrophysics · Physics 2009-11-07 D. Maino , C. Burigana , K. M. Gorski , N. Mandolesi , M. Bersanelli

The presence of astrophysical emissions in microwave observations forces us to perform component separation to extract the Cosmic Microwave Background (CMB) signal. However, even in the most optimistic cases, there are still strongly…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-26 C. Gimeno-Amo , E. Martínez-González , R. B. Barreiro

In paper I (Yu et al. [1]), we show through N-body simulation that a local monotonic Gaussian transformation can significantly reduce non-Gaussianity in a noise-free lensing convergence field. This makes the Gaussianization a promising…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-17 Yu Yu , Pengjie Zhang , Weipeng Lin , Weiguang Cui , James N. Fry

A new technique for reliably identifying point sources in millimeter/sub-millimeter wavelength maps is presented. This method accounts for the frequency dependence of noise in the Fourier domain as well as non-uniformities in the coverage…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 T. A. Perera , G. W. Wilson , K. S. Scott , J. E. Austermann , J. R. Schaar , A. Mancera

Fields in cosmology, such as the matter distribution, are observed by experiments up to experimental noise. The first step in cosmological data analysis is usually to de-noise the observed field using an analytic or simulation driven prior.…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-29 Adam Rouhiainen , Moritz Münchmeyer

In experimental microwave maps, point-sources can strongly affect the estimation of the power-spectrum and/or the test of Gaussianity of the Cosmic Microwave Background (CMB) component. As a consequence, their removal from the sky maps…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Elsa Patricia R. G. Ramos , Roberto Vio , Paola Andreani

Upcoming ground-based cosmic microwave background experiments will provide CMB maps with high sensitivity and resolution that can be used for high fidelity lensing reconstruction. However, the sky coverage will be incomplete and the noise…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-11 Mark Mirmelstein , Julien Carron , Antony Lewis

Large data-sets defined on the sphere arise in many fields. In particular, recent and forthcoming observations of the anisotropies of the cosmic microwave background (CMB) made on the celestial sphere contain approximately three and fifty…

Instrumentation and Methods for Astrophysics · Physics 2011-08-22 J. D. McEwen , Y. Wiaux , D. M. Eyers

We extend the internal template foreground removal method by accounting for spatially varying spectral parameters such as the spectral indices of synchrotron and dust emission and the dust temperature. As the previous algorithm had to…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-04 Kiyotomo Ichiki , Hiroaki Kanai , Nobuhiko Katayama , Eiichiro Komatsu

We develop a new Bayesian method for estimating white noise levels in CMB sky maps, and apply this algorithm to the 5-year WMAP data. We assume that the amplitude of the noise RMS is scaled by a constant value, alpha, relative to a…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-24 N. E. Groeneboom , H. K. Eriksen , K. Gorski , G. Huey , J. Jewell , B. Wandelt

Reliable extraction of cosmological information from observed cosmic microwave background (CMB) maps may require removal of strongly foreground contaminated regions from the analysis. In this article, we employ an artificial neural network…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-13 Srikanta Pal , Pallav Chanda , Rajib Saha

We introduce and study the distribution of an estimator for the normalized bispectrum of the Cosmic Microwave Background (CMB) anisotropy. We use it to construct a goodness of fit statistic to test the coadded 53 and 90 GHz COBE-DMR 4 year…

Astrophysics · Physics 2009-10-30 Pedro G. Ferreira , Joao Magueijo , Krzysztof M. Górski