EDP Sciences
Free access
Volume 409, Number 2, October II 2003
Page(s) 423 - 437
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20031038

A&A 409, 423-437 (2003)
DOI: 10.1051/0004-6361:20031038

Beam deconvolution in noisy CMB maps

C. Burigana1 and D. Sáez2

1  IASF/CNR, Sezione di Bologna, via P. Gobetti, 101, 40129 Bologna, Italy
    e-mail: burigana@bo.iasf.cnr.it
2  Departamento de Astronomía y Astrofísica, Universidad de Valencia, 46100 Burjassot, Valencia, Spain
    e-mail: diego.saez@uv.es

(Received 14 April 2003 / Accepted 2 July 2003)

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 PLANCK 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 PLANCK LFI activities.

Key words: cosmology: cosmic microwave background -- methods: numerical, data analysis

Offprint request: C. Burigana, burigana@bo.iasf.cnr.it

© ESO 2003