Cosmic Shear Statistics and Cosmology

Details Cosmic Shear Statistics and Cosmology Cosmic Shear Statistics and Cosmology

2001-01-29

arxiv.org/abs/astro-ph/0101511v1

Astron.Astrophys.374:757-769,2001

Astronomy and Astrophysics

Astrophysics

13 pages, submitted to A&A

Scientific paper

10.1051/0004-6361:20010766

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 0.60.65 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'.

Affiliated with

Also associated with

No associations

Rating

Cosmic Shear Statistics and Cosmology does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Cosmic Shear Statistics and Cosmology, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cosmic Shear Statistics and Cosmology will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-726688