Bridle, S. and Balan, S.T. and Bethge, M. and Gentile, M. and Harmeling, S. and Heymans, C. and Hirsch, M. and Hosseini, R. and Jarvis, M. and Kirk, D. and Kitching, T. and Kuijken, K. and Lewis, A. and Paulin-Henriksson, S. and Schölkopf, B. and Velander, M. and Voigt, L. and Witherick, D. and Amara, A. and Bernstein, G. and Courbin, F. and Gill, M. and Heavens, A. and Mandelbaum, R. and Massey, R. and Moghaddam, B. and Rassat, Anais and Réfrégier, A. and Rhodes, J. and Schrabback, T. and Shawe-Taylor, J. and Shmakova, M. and van Waerbeke, L. and Wittman, D. (2010) 'Results of the GREAT08 Challenge : an image analysis competition for cosmological lensing.', Monthly notices of the Royal Astronomical Society., 405 (3). pp. 2044-2061.
We present the results of the Gravitational LEnsing Accuracy Testing 2008 (GREAT08) Challenge, a blind analysis challenge to infer weak gravitational lensing shear distortions from images. The primary goal was to stimulate new ideas by presenting the problem to researchers outside the shear measurement community. Six GREAT08 Team methods were presented at the launch of the Challenge and five additional groups submitted results during the 6-month competition. Participants analyzed 30 million simulated galaxies with a range in signal-to-noise ratio, point spread function ellipticity, galaxy size and galaxy type. The large quantity of simulations allowed shear measurement methods to be assessed at a level of accuracy suitable for currently planned future cosmic shear observations for the first time. Different methods perform well in different parts of simulation parameter space and come close to the target level of accuracy in several of these. A number of fresh ideas have emerged as a result of the Challenge including a re-examination of the process of combining information from different galaxies, which reduces the dependence on realistic galaxy modelling. The image simulations will become increasingly sophisticated in future GREAT Challenges, meanwhile the GREAT08 simulations remain as a benchmark for additional developments in shear measurement algorithms.
|Keywords:||Gravitational lensing: weak, Methods: data analysis, Methods: statistical, Techniques: image processing, Cosmology: observations, Large-scale structure of Universe.|
|Full text:||(VoR) Version of Record|
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|Publisher Web site:||http://dx.doi.org/10.1111/j.1365-2966.2010.16598.x|
|Publisher statement:||This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2010 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.|
|Date accepted:||No date available|
|Date deposited:||19 February 2015|
|Date of first online publication:||2010|
|Date first made open access:||No date available|
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