Publication : t01/155
Cosmic Shear Statistics and Cosmology
Van Waerbeke L. (Institut d\'Astrophysique de Paris (IAP-CNRS), 98 bis Bld Arago, F-75014 Paris, FRANCE)Mellier Y. (Institut d\'Astrophysique de Paris (IAP-CNRS), 98 bis Bld Arago, F-75014 Paris, FRANCE)
Radovich M. (Osservatorio Astronomico di Capodimonte, Napoli, Italy)
Bertin E. (Institut d\'Astrophysique de Paris (IAP-CNRS), 98 bis Bld Arago, F-75014 Paris, FRANCE)
Dantel-Fort M. (DEMIRM, Observatoire de Paris, 61, Av. de l’\'Observatoire, F-75014 Paris, FRANCE)
McCracken H.J. (Laboratoire d\'Astrophysique de Marseille (LAM), 38, rue Frédéric Joliot-Curie 13388 Marseille cedex 13, FRANCE)
Le Fèvre O. (Laboratoire d\'Astrophysique de Marseille (LAM), 38, rue Frédéric Joliot-Curie 13388 Marseille cedex 13, FRANCE)
Foucaud S. (Laboratoire d\'Astrophysique de Marseille (LAM), 38, rue Frédéric Joliot-Curie 13388 Marseille cedex 13, FRANCE)
Cuillandre J.-C. (Canada-France-Hawaii-Telescope PO Box 1597, Kamuela, Hawaii 96743, USA)
Erben T. (Institut d\'Astrophysique de Paris (IAP-CNRS), 98 bis Bld Arago, F-75014 Paris, FRANCE)
Jain B. (Dept. of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104-6396, USA)
Schneider P. (Universität Bonn, GERMANY)
Bernardeau F. (CEA, DSM, SPhT (Service de Physique Théorique), F-91191 Gif-sur-Yvette, FRANCE)
Fort B. (Institut d\'Astrophysique de Paris (IAP-CNRS), 98 bis Bld Arago, F-75014 Paris, FRANCE)
Abstract:Année de publication : 2001
We report a measurement of cosmic shear correlations using an effective area of $6.5~sq.~deg.$ of the VIRMOS deep imaging survey in progress at the Canada-France-Hawaii Telescope. We measured various shear correlation functions, the aperture mass statistic and the top-hat smoothed variance of the shear with a detection significance exceeding $12~\sigma$ for each of them. We present results on angular scales from $3$ arc-seconds to half a degree. The consistency of different statistical measures is demonstrated and confirms the lensing origin of the signal through tests that rely on the scalar nature of the gravitational potential. For Cold Dark Matter models we find $\sigma_8 \Omega_0^{0.6}=0.43^{+0.04}_{-0.05}$ at the $95\%$ confidence level. The measurement over almost three decades of scale allows to discuss the effect of the shape of the power spectrum on the cosmological parameter estimation. The degeneracy on $\sigma_8-\Omega_0$ can be broken if priors on the shape of the linear power spectrum (that can be parameterized by $\Gamma$) are assumed. For instance, with $\Gamma=0.21$ and at the $95\%$ confidence level, we obtain $0.6<\sigma_8<1.1$ and $0.2<\Omega_0<0.5$ for open models, and $\sigma_8>0.65$ and $\Omega_0<0.4$ for flat ($\Lambda$-CDM) models. From the tangential/radial modes decomposition we can set an upper limit on the intrinsic shape alignment, which was recently suggested as a possible contribution to the lensing signal. Within the error bars, there is no detection of intrinsic shape alignment for scales larger than $1'$.
Revue : Astron. Astrophys. 374 757-769 (2001)
Preprint : arXiv:astro-ph/0101511
Keywords : Cosmology: theory, dark matter, gravitational lenses, large-scale structure of the universe
Langue : Anglais
Fichier(s) à télécharger :
publi.pdf
