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Observations of Cosmic Microwave Background (CMB) B-mode polarization provide a way to probe primordial gravitational waves and test inflationary predictions. Extragalactic point sources become a major source of contamination after…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-16 Yi-Ming Wang , Wen-Zheng Chen , Yang Liu , Si-Yu Li , Hong Li

We devise a fast and optimal estimator for the amplitude of the bispectrum of clustered Infrared (IR) point-sources. We show how this estimator can account for the cases of partial sky coverage and inhomogeneous noise. Expected detection…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-24 F. Lacasa , N. Aghanim

Point Source (PS) detection is an important issue for future Cosmic Microwave Background (CMB) experiments since they are one of the main contaminants to the recovery of CMB signal at small scales. Improving its multifrequency detection…

Instrumentation and Methods for Astrophysics · Physics 2022-02-09 J. M. Casas , J. González-Nuevo , L. Bonavera , D. Herranz , S. L. Suárez Gómez , M. M. Cueli , D. Crespo , J. D. Santos , M. L. Sánchez , F. Sánchez-Lasheras , F. J. de Cos

Detection of templates (e.g., sources) embedded in low-number count Poisson noise is a common problem in astrophysics. Examples include source detection in X-ray images, gamma-rays, UV, neutrinos, and search for clusters of galaxies and…

Instrumentation and Methods for Astrophysics · Physics 2018-04-11 Eran O. Ofek , Barak Zackay

We apply spherical needlets to the Wilkinson Microwave Anisotropy Probe 5-year cosmic microwave background (CMB) dataset, to search for imprints of non-isotropic features in the CMB sky. We use the needlets localization properties to…

We present the starblade algorithm, a method to separate superimposed point sources from auto-correlated, diffuse flux using a Bayesian model. Point sources are assumed to be independent from each other and to follow a power-law brightness…

Instrumentation and Methods for Astrophysics · Physics 2018-08-07 Jakob Knollmüller , Philipp Frank , Torsten A. Enßlin

In this paper we introduce a new linear filtering technique, the so-called matrix filters, that maximizes the signal-to-interference ratio of compact sources of unknown intensity embedded in a set of images by taking into account the…

Astrophysics · Physics 2009-11-13 D. Herranz , J. L. Sanz

We investigate the use of wavelet transforms in detecting and characterising non-Gaussian structure in maps of the cosmic microwave background (CMB). We apply the method to simulated maps of the Kaiser-Stebbins effect due to cosmic strings…

Astrophysics · Physics 2009-10-31 MP Hobson , AW Jones , AN Lasenby

Observations of the Cosmic Microwave Background (CMB) provide increasingly accurate information about the structure of the Universe at the recombination epoch. Most of this information is encoded in the angular power spectrum of the CMB.…

Astrophysics · Physics 2011-08-01 G. Faÿ , F. Guilloux , M. Betoule , J. -F. Cardoso , J. Delabrouille , M. Le Jeune

One of the largest uncertainties in the Point Source (PS) studies, at Fermi-LAT energies, is the uncertainty in the diffuse background. In general there are two approaches for PS analysis: background-dependent methods, that include modeling…

Instrumentation and Methods for Astrophysics · Physics 2017-07-03 Giacomo Principe , Dmitry Malyshev

Point sources (PS) are one of the main contaminants to the recovery of the cosmic microwave background (CMB) signal at small scales, and their detection is important for the next generation of CMB experiments. We develop a method (PoSeIDoN)…

Astrophysics of Galaxies · Physics 2021-04-14 L. Bonavera , S. L. Suarez Gomez , J. González-Nuevo , M. M. Cueli , J. D. Santos , M. L. Sanchez , R. Muñiz , F. J. de Cos

We present two new source extraction methods, based on Bayesian model selection and using the Bayesian Information Criterion (BIC). The first is a source detection filter, able to simultaneously detect point sources and estimate the image…

Astrophysics · Physics 2011-02-11 Richard S. Savage , Seb Oliver

Small angular scale (high l) studies of cosmic microwave background anisotropies require accurate knowledge of the statistical properties of extragalactic sources at cm-mm wavelengths. We have used a 30 GHz dual-beam receiver (OCRA-p) on…

Clusters of galaxies produce negative features at wavelengths $\lambda > 1.25$ mm in CMB maps, by means of the thermal SZ effect, while point radio sources produce positive peaks. This fact implies that a distribution of unresolved SZ…

Astrophysics · Physics 2009-11-07 J. A. Rubino-Martin , R. A. Sunyaev

Wavelets are scaleable, oscillatory functions that deviate from zero only within a limited spatial regime and have average value zero. In addition to their use as source characterizers, wavelet functions are rapidly gaining currency within…

Astrophysics · Physics 2009-11-07 Peter E. Freeman , Vinay Kashyap , Robert Rosner , Donald Q. Lamb

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

As Cosmic Microwave Background (CMB) measurements are becoming more ambitious, the issue of foreground contamination is becoming more pressing. This is especially true at the level of sensitivity, angular resolution and for the sky coverage…

Astrophysics · Physics 2009-10-31 François R. Bouchet , Richard Gispert

The cosmic microwave background radiation is supposed to be Gaussian and this hypothesis is in good agreement with the recent very accurate measurements. Nonetheless a tiny amount of non-Gaussianity is predicted by the standard inflation…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-06 Davide Pietrobon

The analysis of the submm anisotropies that will be mapped by the forthcoming MAP and PLANCK satellites requires careful foreground subtraction before measuring CMB fluctuations. Among these, the foreground due to IR/submm thermal radiation…

Astrophysics · Physics 2007-05-23 B. Guiderdoni

The cosmic microwave background (CMB) is a relic radiation of the Big Bang and as such it contains a wealth of cosmological information. Statistical analyses of the CMB, in conjunction with other cosmological observables, represent some of…