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相关论文: Estimates of unresolved point sources contribution…

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We present measurements of a population of matched radio sources at 1.4 and 5 GHz down to a flux limit of 1.5 mJy in 7 sq. degs. of the NOAO Deep Field South. We find a significant fraction of sources with inverted spectral indices that all…

宇宙学与河外天体物理 · 物理学 2015-06-04 Michael D. Schneider , Robert H. Becker , Willem de Vries , Richard L. White

The detection of point sources in Cosmic Microwave Background maps is usually based on a single-frequency approach, whereby maps at each frequency are filtered separately and the spectral information on the sources is derived combining the…

宇宙学与河外天体物理 · 物理学 2012-04-16 L. F. Lanz , D. Herranz , M. López-Caniego , J. González-Nuevo , G. de Zotti , M. Massardi , J. L. Sanz

In (Scodeller et al.) a new and extended point source catalogue obtained from the WMAP 7-year data was presented. It includes most of the sources included in the standard WMAP 7-year point source catalogues as well as a large number of new…

宇宙学与河外天体物理 · 物理学 2012-12-10 Sandro Scodeller , Frode K. Hansen

We present the angular power spectrum derived from the first-year Wilkinson Microwave Anisotropy Probe (WMAP) sky maps. We study a variety of power spectrum estimation methods and data combinations and demonstrate that the results are…

We estimate the contribution of extragalactic radio sources to fluctuations in sky temperature over the range of frequencies (10-300 GHz) used for Cosmic Microwave Background (CMB) anisotropy measurements. CMB anisotropy observations at…

天体物理学 · 物理学 2007-05-23 Aaron Sokasian , Eric Gawiser , George F. Smoot

We have developed a new needlet based method to detect point sources in cosmic microwave background (CMB) maps and have applied it to the WMAP 7 year data. We use both the individual frequency channels as well as internal templates, the…

宇宙学与河外天体物理 · 物理学 2012-07-11 Sandro Scodeller , Frode K. Hansen , Domenico Marinucci

We review estimates of small scale fluctuations due to extragalactic point sources in the Planck Surveyor frequency bands. While our undestanding of the spectral and evolutionary properties of these sources is far from complete,…

天体物理学 · 物理学 2007-05-23 G. De Zotti , L. Toffolatti , G. L. Granato

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…

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…

天体物理学 · 物理学 2008-11-26 M. Tucci , E. Martinez-Gonzalez , L. Toffolatti , J. Gonzalez-Nuevo , G. De Zotti

We use the Wilkinson Microwave Anisotropy Probe 7-year data (WMAP7) to further probe point source detection technique in the sky maps of the cosmic microwave background (CMB) radiation. The method by Tegmark et al. for foreground reduced…

宇宙学与河外天体物理 · 物理学 2013-07-30 H. G. Khachatryan , G. Nurbaeva , D. Pfenniger , G. Meylan

We detect a dip of 20-45% in the surface brightness and number counts of NVSS sources smoothed to a few degrees at the location of the WMAP cold spot. The dip has structure on scales of approximately 1-10 degrees. Together with independent…

天体物理学 · 物理学 2009-06-23 Lawrence Rudnick , Shea Brown , Liliya R. Williams

The point source list of the Wilkinson Microwave Anisotropy Probe (WMAP) is a uniform, all-sky catalogue of bright sources with flux density measurements at high (up to 94 GHz) radio frequencies. We investigated the five-year WMAP list to…

宇宙学与河外天体物理 · 物理学 2011-06-21 K. Gereb , S. Frey

Contribution of resolved and unresolved extragalactic point sources to the low-frequency sky spectrum is a potentially non-negligible part of the astrophysical foregrounds for cosmic dawn 21-cm experiments. The clustering of such point…

宇宙学与河外天体物理 · 物理学 2024-10-01 Shikhar Mittal , Girish Kulkarni , Dominic Anstey , Eloy de Lera Acedo

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…

The 100-m Robert C. Byrd Green Bank Telescope (GBT) and the Owens Valley Radio Observatory (OVRO) 40-m radio telescope have been used to conduct a survey of 3165 known extragalactic radio sources over 143 square degrees of the sky. Target…

宇宙学与河外天体物理 · 物理学 2011-02-11 B. S. Mason , L. C. Weintraub , J. L. Sievers , J. R. Bond , S. T. Myers , T. J. Pearson , A. C. S. Readhead , M. C. Shepherd

The remarkable improvement in the estimates of different cosmological parameters in recent years has been largely spearheaded by accurate measurements of the angular power spectrum of Cosmic Microwave Background (CMB) radiation. This has…

天体物理学 · 物理学 2011-04-11 Tarun Souradeep , Rajib Saha , Pankaj Jain

In this paper we present forecasts of the contamination on different shapes of the primordial non-Gaussianity fnl parameter -- detectable on future Cosmic Microwave Background (CMB) high--resolution anisotropy maps -- produced by unresolved…

宇宙学与河外天体物理 · 物理学 2015-06-12 A. Curto , M. Tucci , J. Gonzalez-Nuevo , L. Toffolatti , E. Martinez-Gonzalez , F. Argueso , A. Lapi , M. Lopez-Caniego

Missions such as WMAP or Planck measure full-sky fluctuations of the cosmic microwave background and foregrounds, among which bright compact source emissions cover a significant fraction of the sky. To accurately estimate the diffuse…

天体物理仪器与方法 · 物理学 2015-06-19 F. C. Sureau , J. -L. Starck , J. Bobin , P. Paykari , A. Rassat

In the context of the study of the ISW, we revisit the angular cross correlation of WMAP CMB data with the NVSS radio survey. We compute 2-point cross functions between the two surveys in real and in Fourier space, paying particular…

宇宙学与河外天体物理 · 物理学 2015-05-14 Carlos Hernandez-Monteagudo