EDP Sciences
Free access
Issue
A&A
Volume 413, Number 2, January II 2004
Page(s) 465 - 476
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20034172


A&A 413, 465-476 (2004)
DOI: 10.1051/0004-6361:20034172

Analysis of two-point statistics of cosmic shear

II. Optimizing the survey geometry
M. Kilbinger1 and P. Schneider1, 2

1  Institut f. Astrophysik u. Extr. Forschung, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
2  Max-Planck-Institut f. Astrophysik, Postfach 1317, 85741 Garching, Germany

(Received 8 August 2003 / Accepted 30 September 2003)

Abstract
We present simulations of a cosmic shear survey and show how the survey geometry influences the accuracy of determination of cosmological parameters. We numerically calculate the full covariance matrices $\mbox{Cov}$ of two-point statistics of cosmic shear, based on the expressions derived in the first paper of this series. The individual terms are compared for two survey geometries with large and small cosmic variance. We use analyses based on maximum likelihood of $\mbox{Cov}$ and the Fisher information matrix in order to derive expected constraints on cosmological parameters. As an illustrative example, we simulate various survey geometries consisting of 300 individual fields of $13^\prime
\times 13^\prime$ size, placed (semi-)randomly into patches which are assumed to be widely separated on the sky and therefore uncorrelated. Using the aperture mass statistics $\left\langle M_{\rm ap}^2 \right\rangle$, the optimum survey consists of 10 patches with 30 images in each patch. If $\Omega_{\rm m},
\sigma_8$ and $\Gamma$ are supposed to be extracted from the data, the minimum variance bounds on these three parameters are 0.17, 0.25 and 0.04 respectively. These variances increase slightly when the initial power spectrum index $n_{\rm s}$ is also to be determined from the data. The cosmological constant is only poorly constrained.


Key words: cosmology: observations -- gravitational lensing -- cosmology: large-scale structure of Universe

Offprint request: M. Kilbinger, kilbinge@astro.uni-bonn.de

SIMBAD Objects in preparation



© ESO 2004