EDP Sciences
Free access
Volume 410, Number 1, October IV 2003
Page(s) 11 - 16
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20030869

A&A 410, 11-16 (2003)
DOI: 10.1051/0004-6361:20030869

Goodness-of-fit statistics and CMB data sets

M. Douspis1, 2, J. G. Bartlett1, 3 and A. Blanchard1

1  Observatoire Midi-Pyrénées, 14 Av. E. Belin, 31400 Toulouse, France Unité associée au CNRS (http://webast.ast.obs-mip.fr)
2  Astrophysics, Denis Wylkinson Building, Keble Road, Oxford OX1 3RH, UK (http://www-astro.physics.ox.ac.uk)
3  APC, Université Paris 7, 11 Pl. Marcelin-Berthelot, Paris Cedex 05, France (http://apc-p7.org/)

(Received 25 September 2001 / Accepted 19 May 2003)

Application of a Goodness-of-fit (GOF) statistic is an essential element in parameter estimation. We discuss the computation of GOF when estimating parameters from anisotropy measurements of the cosmic microwave background (CMB), and we propose two GOF statistics to be used when employing approximate band-power likelihood functions. They are based on an approximate form for the distribution of band-power estimators that requires only minimal experimental information to construct. Monte Carlo simulations of CMB experiments show that the proposed form describes the true distributions quite well. We apply these GOF statistics to current CMB anisotropy data and discuss the results.

Key words: cosmology: cosmic microwave background -- cosmology: observations -- cosmology: theory

Offprint request: M. Douspis, douspis@astro.ox.ac.uk

© ESO 2003