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Results of the GREAT08 Challenge: An image analysis competition for cosmological lensing

2010

Article

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We present the results of the 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 sophis- ticated in future GREAT challenges, meanwhile the GREAT08 simulations remain as a benchmark for additional developments in shear measurement algorithms.

Author(s): Bridle, S. and Balan, ST. 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, A. and Refregier, A. and Rhodes, J. and Schrabback, T. and Shawe-Taylor, J. and Shmakova, M. and van Waerbeke, L. and Wittman, D.
Journal: Monthly Notices of the Royal Astronomical Society
Volume: 405
Number (issue): 3
Pages: 2044-2061
Year: 2010
Month: July
Day: 0

Department(s): Empirical Inference
Bibtex Type: Article (article)

Digital: 0
DOI: 10.1111/j.1365-2966.2010.16598.x
Language: en
Organization: Max-Planck-Gesellschaft
School: Biologische Kybernetik

Links: Web

BibTex

@article{6340,
  title = {Results of the GREAT08 Challenge: An image analysis competition for cosmological lensing},
  author = {Bridle, S. and Balan, ST. 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 Sch{\"o}lkopf, 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, A. and Refregier, A. and Rhodes, J. and Schrabback, T. and Shawe-Taylor, J. and Shmakova, M. and van Waerbeke, L. and Wittman, D.},
  journal = {Monthly Notices of the Royal Astronomical Society},
  volume = {405},
  number = {3},
  pages = {2044-2061},
  organization = {Max-Planck-Gesellschaft},
  school = {Biologische Kybernetik},
  month = jul,
  year = {2010},
  month_numeric = {7}
}