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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…

宇宙学与河外天体物理 · 物理学 2015-05-19 Elsa Patricia R. G. Ramos , Roberto Vio , Paola Andreani

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 stack WMAP 7-year temperature data around extragalactic point sources, showing that the profiles are consistent with WMAP's beam models, in disagreement with the findings of Sawangwit & Shanks (2010). These results require that the…

宇宙学与河外天体物理 · 物理学 2015-06-03 Kasey W. Schultz , Kevin M. Huffenberger

We apply a Cross-correlation (CC) method developed previously for detecting gamma-ray point sources to the WMAP first year data by using the Point-Spread Function of WMAP and obtain a full sky CC coefficient map. Analyzing this map, we find…

天体物理学 · 物理学 2009-11-11 Jian Yin Nie , Shuang Nan Zhang

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

Point-source contamination in high-precision Cosmic Microwave Background (CMB) maps severely affects the precision of cosmological parameter estimates. Among the methods that have been proposed for source detection, wavelet techniques based…

天体物理学 · 物理学 2009-11-07 R. Vio , L. Tenorio , W. Wamsteker

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 present the results of an extragalactic point source search using the five-year WMAP 41, 61 and 94 GHz (Q-, V- and W-band) temperature maps. This work is an extension of our point source search in the WMAP maps applying a CMB-free…

天体物理学 · 物理学 2011-02-11 Xi Chen , Edward L. Wright

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

We present an alternative estimate of the unresolved point source contribution to the WMAP temperature power spectrum based on current knowledge of sources from radio surveys in the 1.4-90 GHz range. We implement a stochastic extrapolation…

宇宙学与河外天体物理 · 物理学 2015-05-18 Loris P. L. Colombo , Elena Pierpaoli

The faint radio point sources that are unresolved in cosmic microwave background (CMB) anisotropy maps are likely to be a biased tracer of the large-scale structure dark matter distribution. While the shot-noise contribution to the angular…

天体物理学 · 物理学 2008-11-26 Paolo Serra , Asantha Cooray , Alexandre Amblard , Luca Pagano , Alessandro Melchiorri

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

We discuss point sources foregrounds for the MAP experiment. We consider several possible strategies for removing them and we assess how the statistics of the CMB signal are affected by the residual sources. Assuming a power law…

天体物理学 · 物理学 2009-11-07 Elena Pierpaoli

The WMAP 7-year temperature maps have been re-analized to extract a CMB map and CMB power spectrum with reduced contamination by astrophysical foregrounds and noise. The method used is based on linear combinations of WMAP data and…

宇宙学与河外天体物理 · 物理学 2015-05-28 Soumen Basak , Jacques Delabrouille

We analyze whether there is any residual foreground contamination in the cleaned WMAP 7 years data for the differential assemblies, Q, V and W. We calculate the correlation between the foreground map, from which long wavelength correlations…

宇宙学与河外天体物理 · 物理学 2015-06-11 Pravabati Chingangbam , Changbom Park

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…

天体物理学 · 物理学 2009-11-13 Xi Chen , Edward L. Wright

Using a set of multifrequency cross spectra computed from the 3 year WMAP sky maps, we fit for the unresolved point-source contribution. For a white-noise power spectrum, we find a Q-band amplitude of A=0.011 +/- 0.001 muK^2 sr (antenna…

天体物理学 · 物理学 2011-02-11 K. M. Huffenberger , H. K. Eriksen , F. K. Hansen

For high-precision cosmic microwave background (CMB) experiments, contamination from extragalactic point sources is a major concern. It is therefore useful to be able to detect and discard point source contaminated pixels using the map…

天体物理学 · 物理学 2009-10-30 Max Tegmark , Angelica de Oliveira-Costa

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…

A new method for removing point radio sources and other non-Gaussian noise is proposed as a means of improving the accuracy of estimates of the angular power spectrum of the cosmic microwave background (CMB). The main idea of the method is…

天体物理学 · 物理学 2009-11-13 Anisa T. Bajkova
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