A speedy pixon image reconstruction algorithm     

Vincent Eke 《Monthly notices of the Royal Astronomical Society》2001,324(1):108-118

A speedy pixon algorithm for image reconstruction is described. Two applications of the method to simulated astronomical data sets are also reported. In one case, galaxy clusters are extracted from multiwavelength microwave sky maps using the spectral dependence of the Sunyaev–Zel'dovich effect to distinguish them from the microwave background fluctuations and the instrumental noise. The second example involves the recovery of a sharply peaked emission profile, such as might be produced by a galaxy cluster observed in X-rays. These simulations show the ability of the technique both to detect sources in low signal-to-noise ratio data and to deconvolve a telescope beam in order to recover the internal structure of a source.  相似文献   

Cosmic microwave background power spectrum estimation with the destriping technique     

T. Poutanen  D. Maino  H. Kurki-Suonio  E. Keihänen  E. Hivon 《Monthly notices of the Royal Astronomical Society》2004,353(1):43-58

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Parameter constraints for flat cosmologies from cosmic microwave background and 2dFGRS power spectra     

Will J. Percival  Will Sutherland  John A. Peacock  Carlton M. Baugh  Joss Bland-Hawthorn  Terry Bridges  Russell Cannon  Shaun Cole  Matthew Colless  Chris Collins  Warrick Couch  Gavin Dalton  Roberto De Propris  Simon P. Driver  George Efstathiou  Richard S. Ellis  Carlos S. Frenk  Karl Glazebrook  Carole Jackson  Ofer Lahav  Ian Lewis  Stuart Lumsden  Steve Maddox  Stephen Moody  Peder Norberg  Bruce A. Peterson  Keith Taylor 《Monthly notices of the Royal Astronomical Society》2002,337(3):1068-1080

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Deep 1.4-GHz observations of diffuse polarized emission     

E. Carretti  S. Poppi  W. Reich  P. Reich  E. Fürst  G. Bernardi  S. Cortiglioni  C. Sbarra 《Monthly notices of the Royal Astronomical Society》2006,367(1):132-138

Polarized diffuse emission observations at 1.4 GHz in a high Galactic latitude area of the Northern celestial hemisphere are presented. The  3.2 × 3.2 deg²  field, centred at  RA = 10^h58^m, Dec. =+42°18' (B1950)  , has Galactic coordinates   l ∼ 172°, b ∼+63°  and is located in the region selected as northern target of the Balloon-borne Radiometers for Sky Polarization Observations experiment. Observations have been performed with the Effelsberg 100-m telescope. We find that the angular power spectra of the E and B modes have slopes of  β _E =−1.79 ± 0.13  and  β _B =−1.74 ± 0.12  , respectively. Because of the very high Galactic latitude and the smooth emission, a weak Faraday rotation action is expected, which allows both a fair extrapolation to cosmic microwave background polarization (CMBP) frequencies and an estimate of the contamination by the Galactic synchrotron emission. We extrapolate the E -mode spectrum up to 32 GHz and confirm the possibility to safely detect the CMBP E -mode signal in the Ka band found in another low-emission region. Extrapolated up to 90 GHz, the Galactic synchrotron B mode looks to compete with the cosmic signal only for models with a tensor-to-scalar perturbation power ratio   T / S < 0.001  , which is even lower than the T / S value of 0.01 found to be accessible in the only other high Galactic latitude area investigated to date. This suggests that values as low as   T / S = 0.01  might be accessed at high Galactic latitudes. Such low-emission values can allow a significant redshift of the best frequency to detect the CMBP B mode, also reducing the contamination by Galactic dust, and opening interesting perspectives to investigate inflation models.  相似文献   

On the large-angle anomalies of the microwave sky   总被引：1，自引：0，他引：1  

Craig J. Copi  Dragan Huterer  Dominik J. Schwarz  Glenn D. Starkman 《Monthly notices of the Royal Astronomical Society》2006,367(1):79-102

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The properties of extragalactic radio sources selected at 20 GHz     

Elaine M. Sadler  Roberto Ricci  Ronald D. Ekers  J. A. Ekers  Paul J. Hancock  Carole A. Jackson  Michael J. Kesteven  Tara Murphy  Chris Phillips  Robert F. Reinfrank  Lister Staveley-Smith  Ravi Subrahmanyan  Mark A. Walker  Warwick E. Wilson  Gianfranco De Zotti 《Monthly notices of the Royal Astronomical Society》2006,371(2):898-914

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The Cosmic Foreground Explorer (COFE): A balloon-borne microwave polarimeter to characterize polarized foregrounds     

Rodrigo Leonardi  Brian Williams  Marco Bersanelli  Ivan Ferreira  Philip M. Lubin  Peter R. Meinhold  Hugh O&#x;Neill  Nathan C. Stebor  Fabrizio Villa  Thyrso Villela  Carlos A. Wuensche 《New Astronomy Reviews》2006,50(11-12):977

The COsmic Foreground Explorer (COFE) is a balloon-borne microwave polarimeter designed to measure the low-frequency and low-ℓ characteristics of dominant diffuse polarized foregrounds. Short duration balloon flights from the Northern and Southern Hemispheres will allow the telescope to cover up to 80% of the sky with an expected sensitivity per pixel better than 100 μK/deg² from 10 GHz to 20 GHz. This is an important effort toward characterizing the polarized foregrounds for future CMB experiments, in particular the ones that aim to detect primordial gravity wave signatures in the CMB polarization angular power spectrum.  相似文献   

Bumpy power spectra and ΔT/T     

Louise M. Griffiths  Joseph Silk  Saleem Zaroubi 《Monthly notices of the Royal Astronomical Society》2001,324(3):712-716

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Inhomogeneous primordial baryon distributions on subgalactic scales: high-z galaxy formation with warm dark matter     

Jesper Sommer-Larsen  Pavel Naselsky  Igor Novikov  Martin Götz 《Monthly notices of the Royal Astronomical Society》2004,352(1):299-310

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华北地区早期背景地震活动特征与M≥7级大震危险区预测   总被引：1，自引：0，他引：1  

刁守中  郭爱香  王红卫 《高原地震》1994,(2)

本文对华北地区第三、第四活动期早期背景地震研究表明，本区早期背景地震空间分布大体勾画出相应活动期内７级以上大震活动主体区域的基本轮廓，而早期背景地震集中区指示了未来７、８级大震的可能部位。  相似文献