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First cosmic shear results from the Canada-France-Hawaii Telescope Wide Synoptic Legacy Survey

Authors :
Yannick Mellier
Liping Fu
Laura C. Parker
K. Benabed
Michael J. Hudson
Henk Hoekstra
Ismael Tereno
Elisabetta Semboloni
L. van Waerbeke
Department of Physics and Astronomy, University of Victoria
Institut d'Astrophysique de Paris (IAP)
Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA)
École normale supérieure - Paris (ENS-PSL)
Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris
Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP)
Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)
Department of Physics and Astronomy, University of British Columbia
Department of Physics, University of Waterloo
Departamento de Fisica, Universidade de Lisboa
Henry, Florence
Source :
The Astrophysical Journal, The Astrophysical Journal, 2006, 647, pp.116-127
Publication Year :
2005

Abstract

We present the first measurements of the weak gravitational lensing signal induced by the large scale mass distribution from data obtained as part of the ongoing Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). The data used in this analysis are from the Wide Synoptic Survey, which aims to image ~170 square degree in five filters. We have analysed ~22 deg2 (31 pointings) of i' data spread over two of the three survey fields. These data are of excellent quality and the results bode well for the remainder of the survey: we do not detect a significant `B'-mode, suggesting that residual systematics are negligible at the current level of accuracy. Assuming a Cold Dark Matter model and marginalising over the Hubble parameter h=[0.6,0.8], the source redshift distribution and systematics, we constrain sigma_8, the amplitude of the matter power spectrum. At a fiducial matter density Omega_m=0.3 we find sigma_8=0.85+-0.06. This estimate is in excellent agreement with previous studies. Combination of our results with those from the Deep component of the CFHTLS enables us to place a constraint on a constant equation of state for the dark energy, based on cosmic shear data alone. We find that w_0<br />Comment: Submitted to ApJ

Details

Language :
English
ISSN :
0004637X and 15384357
Database :
OpenAIRE
Journal :
The Astrophysical Journal, The Astrophysical Journal, 2006, 647, pp.116-127
Accession number :
edsair.doi.dedup.....2332fc62df0c362c4892f3464cb10fe6