Non-circular rotating beams and CMB experiments

Arnau, J. V.; Aliaga, A. M.; Sáez, D.

doi:10.1051/0004-6361:20011681

Cited by 8 publications

(16 citation statements)

References 8 publications

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“…Since we are concerned with small squared regularly pixelized maps, the power spectrum estimator described in Arnau, Aliaga & Sáez (2002) applies. Although this estimator is used as the basic one in this paper, some results are compared with those of the code anafast included in the healpix package.…”

Section: On the Angular Power Spectrum Of The Rees–sciama Effectmentioning

confidence: 99%

On the Rees-Sciama effect: maps and statistics

Puchades

Fullana

Arnau

et al. 2006

Monthly Notices of the Royal Astronomical Society

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Small maps of the Rees-Sciama (RS) effect are simulated by using an appropriate N-body code and a certain ray-tracing procedure. A method designed for the statistical analysis of cosmic microwave background (CMB) maps is applied to study the resulting simulations. These techniques, recently proposed --by our team-- to consider lens deformations of the CMB, are adapted to deal with the RS effect. This effect and the deviations from Gaussianity associated to it seem to be too small to be detected in the near future. This conclusion follows from our estimation of both the RS angular power spectrum and the RS reduced n-direction correlation functions for n<7.Comment: 11 pages, 13 figures, to appear in MNRA

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Section: On the Angular Power Spectrum Of The Rees–sciama Effectmentioning

confidence: 99%

On the Rees-Sciama effect: maps and statistics

Puchades

Fullana

Arnau

et al. 2006

Monthly Notices of the Royal Astronomical Society

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“…is assumed, as in Burigana et al (1998) and Arnau et al (2002). It is also assumed that quantities σ θ and σ φ obey the relations σ θ σ φ = σ 2 and σ θ /σ φ = 1.3, where σ = 4.54 (θ FWHM 10.68 ).…”

Section: Case A: Noiseless Small Patchesmentioning

confidence: 99%

“…If not taken into account in the data analysis, the main beam distortion introduces a systematic effect in the data Mandolesi et al 2000ab) that affects the reconstructed map quality and, in particular, the recovery of the angular power spectrum of the CMB anisotropy Send offprint requests to: C. Burigana, e-mail: burigana@bo.iasf.cnr.it 1 http://astro.estec.esa.nl/Planck/ Arnau et al 2002;Fosalba et al 2002).…”

Section: Introductionmentioning

confidence: 99%

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Beam deconvolution in noisy CMB maps

Burigana¹,

Sáez²

2003

A&A

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Abstract. The subject of this paper is beam deconvolution in small angular scale CMB experiments. The beam effect is reversed using the Jacobi iterative method, which was designed to solved systems of algebraic linear equations. The beam is a non circular one which moves according to the observational strategy. A certain realistic level of Gaussian instrumental noise is assumed. The method applies to small scale CMB experiments in general (cases A and B), but we have put particular attention on P mission at 100 GHz (cases C and D). In cases B and D, where noise is present, deconvolution allows to correct the main beam distortion effect and recover the initial angular power spectrum up to the end of the fifth acoustic peak. An encouraging result whose importance is analyzed in detail. More work about deconvolution in the presence of other systematics is in progress. This paper is related to the P LFI activities.

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“…Since the PSFs corresponding to the images obtained at the various frequencies can be quite dissimilar, simultaneous deblurring can be useful to improve the extraction of CMB information from the data. Unfortunately, since the PSF of PLANCK's instruments is expected to be non-circular and, because of the observational strategy, to rotate during the observations (Arnau et al 2002;Burigana & Saez 2003), the computational advantages provided by the methodology of Vio et al (2004) cannot be exploited.…”

Section: Introductionmentioning

confidence: 99%

Multiple-image deblurring with spatially-variant point spread functions

Vio

Nagy²,

Wamsteker

2005

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Abstract. We generalize a reliable and efficient algorithm, to deal with the case of spatially-variant PSFs. The algorithm was developed in the context of a least-square (LS) approach, to estimate the image corresponding to a given object when a set of observed images are available with different and spatially-invariant PSFs. Noise is assumed additive and Gaussian. The proposed algorithm allows the use of the classical LS single-image deblurring techniques for the simultaneous deblurring of the observed images, with obvious advantages both for computational cost and ease of implementation. Its performance and limitations, also in the case of Poissonian noise, are analyzed through numerical simulations. In an appendix we also present a novel, computationally efficient deblurring algorithm that is based on a Singular Value Decomposition (SVD) approximation of the variant PSF, and which is usable with any standard space-invariant direct deblurring algorithm. The corresponding Matlab code is made available.

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Non-circular rotating beams and CMB experiments

Cited by 8 publications

References 8 publications

On the Rees-Sciama effect: maps and statistics

On the Rees-Sciama effect: maps and statistics

Beam deconvolution in noisy CMB maps

Multiple-image deblurring with spatially-variant point spread functions

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