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We present a method to simulate the polarization properties of extragalactic radio sources at microwave frequencies. Polarization measurements of nearly 2x10^6 sources at 1.4 GHz are provided by the NVSS survey. Using this catalogue and the…

Astrophysics · Physics 2008-11-26 M. Tucci , E. Martinez-Gonzalez , L. Toffolatti , J. Gonzalez-Nuevo , G. De Zotti

We present polarization measurements of extragalactic radio sources observed during the Cosmic Microwave Background polarization survey of the Q/U Imaging Experiment (QUIET), operating at 43 GHz (Q-band) and 95 GHz (W-band). We examine…

Although interesting in themselves, extragalactic sources emitting in the microwave range (mainly radio-loud active galactic nuclei and dusty galaxies) are also considered a contaminant from the point of view of Cosmic Microwave Background…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 P. Diego-Palazuelos , P. Vielva , D. Herranz

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

Recent detailed simulations have shown that an insufficiently accurate characterization of the contamination of unresolved polarized extragalactic sources can seriously bias measurements of the primordial cosmic microwave background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-10 T. Trombetti , C. Burigana , G. De Zotti , V. Galluzzi , M. Massardi

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

Given a set of images, whose pixel values can be considered as the components of a vector, it is interesting to estimate the modulus of such a vector in some localised areas corresponding to a compact signal. For instance, the…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-02 F. Argueso , J. L. Sanz , D. Herranz , M. Lopez-Caniego , J. Gonzalez-Nuevo

The detection of polarized sources in the WMAP 5-year data is a very difficult task. The maps are dominated by instrumental noise and only a handful of sources show up as clear peaks in the Q and U maps. Optimal linear filters applied at…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 M. Lopez-Caniego , M. Massardi , J. Gonzalez-Nuevo , L. Lanz , D. Herranz , G. De Zotti , J. L. Sanz , F. Argueso

We propose a machine-learning-based technique to determine the number density of radio sources as a function of their flux density, for use in next-generation radio surveys. The method uses a convolutional neural network trained on…

Instrumentation and Methods for Astrophysics · Physics 2024-01-17 Elisa Todarello , Andre Scaffidi , Marco Regis , Marco Taoso

We study the polarisation properties of extragalactic sources at 95 and 150 GHz in the SPTpol 500 deg$^2$ survey. We estimate the polarised power by stacking maps at known source positions, and correct for noise bias by subtracting the mean…

We investigate the statistical properties of the polarized emission of extragalactic radio sources and estimate their contribution to the power spectrum of polarization fluctuations in the microwave region. The basic ingredients of our…

Astrophysics · Physics 2009-11-07 D. Mesa , C. Baccigalupi , G. De Zotti , L. Gregorini , K. -H. Mack , M. Vigotti , U. Klein

Computing polarised intensities from noisy data in Stokes U and Q suffers from a positive bias that should be suppressed. To develop a correction method that, when applied to maps, should provide a distribution of polarised intensity that…

Instrumentation and Methods for Astrophysics · Physics 2017-04-05 Peter Müller , Rainer Beck , Marita Krause

We propose a machine learning approach to the blind detection of extragalactic point sources on maps of the temperature anisotropies of the cosmic microwave background. Using realistic simulations of the microwave sky as seen by Planck, we…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-01 P. Diego-Palazuelos , R. B. Barreiro , P. Vielva , D. Balbás , M. López-Caniego , D. Herranz , B. Casaponsa

The estimation of the polarization $P$ of extragalactic compact sources in Cosmic Microwave Background images is a very important task in order to clean these images for cosmological purposes -- as, for example, to constrain the…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-07 D. Herranz , F. Argüeso , L. Toffolatti , A. Manjón-García , M. López-Caniego

The characterization of the dust polarization foreground to the Cosmic Microwave Background (CMB) is a necessary step towards the detection of the B-mode signal associated with primordial gravitational waves. We present a method to simulate…

We estimate the average fractional polarisation at 143, 217 and 353 GHz of a sample of 4697 extragalactic dusty sources by applying stacking technique. The sample is selected from the second version of the Planck Catalogue of Compact…

Astrophysics of Galaxies · Physics 2023-04-05 L. Bonavera , J. Gonzalez-Nuevo , B. De Marco , F. Argüeso , L. Toffolatti

In our previous study, we introduced a machine-learning technique, namely CMBFSCNN, for the removal of foreground contamination in cosmic microwave background (CMB) polarization data. This method was successfully employed on actual…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-19 Ye-Peng Yan , Si-Yu Li , Guo-Jian Wang , Zirui Zhang , Jun-Qing Xia

The detection of Cosmic Microwave Background primordial $B$-mode polarization would constitute a ``smoking gun" signal of primordial gravitational waves. However, this measurement requires accurate removal of polarized Galactic foregrounds…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Luca Gomez Bachar , Cora Dvorkin , Alberto Daniel Supanitsky

The search for primordial gravitational waves is a central goal of cosmic microwave background (CMB) surveys. Isolating the characteristic $B$-mode polarization signal sourced by primordial gravitational waves is challenging for several…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-23 Eric Guzman , Joel Meyers

Recovering the polarized cosmic microwave background (CMB) is essential for shedding light on the exponential expansion of the very early Universe, known as cosmic inflation. Achieving this goal requires not only improved instrumental…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-18 J. M. Casas , L. Bonavera , J. González-Nuevo , G. Puglisi , C. Baccigalupi , S. R. Cabo , M. M. Cueli , D. Crespo , C. González-Gutiérrez , F. J. de Cos
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