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GaBoDS: The Garching-Bonn Deep Survey: VI. Cosmic shear analysis

M. Hetterscheidt·P. Simon·M. Schirmer·H. Hildebrandt·T. Schrabback·T. Erben·P. Schneider
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Abstract

Aims. We present a cosmic shear analysis and data validation of 15 square degree high-quality R-band data of the Garching-Bonn Deep Survey obtained with the Wide Field Imager of the MPG/ESO 2.2m telescope. Methods. We measure the two-point shear correlation functions to calculate the aperture mass dispersion. Both statistics are used to perform the data quality control. Combining the cosmic shear signal with a photometric redshift distribution of a galaxy sub-sample obtained from two square degree of UBVRI-band observations of the Deep Public Survey we determine constraints for the matter density Omega_m, the mass power spectrum normalisation sigma_8 and the dark energy density Omega_Lambda in the magnitude interval R in [21.5,24.5]. In this magnitude interval the effective number density of source galaxies is n=12.5/sq. arcmin, and their mean redshift is z_m=0.78. To estimate the posterior likelihood we employ the Monte Carlo Markov Chain method. Results. Using the aperture mass dispersion we obtain for the mass power spectrum normalisation sigma_8=0.80 +- 0.10 (1 sigma statistical error) at a fixed matter density Omega_m=0.30 assuming a flat universe with negligible baryon content and marginalising over the Hubble parameter and the uncertainties in the fitted redshift distribution.

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M. Hetterscheidt, P. Simon, M. Schirmer, H. Hildebrandt, T. Schrabback, T. Erben, P. Schneider. 2006-06-23. GaBoDS: The Garching-Bonn Deep Survey: VI. Cosmic shear analysis. https://doi.org/10.1051/0004-6361%3A20065885

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