Bayesian galaxy shape measurement for weak lensing surveys - I. Methodology and a fast-fitting algorithm

L. Miller*, T. D. Kitching, C. Heymans, A. F. Heavens, L. Van Waerbeke

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

The principles of measuring the shapes of galaxies by a model-fitting approach are discussed in the context of shape measurement for surveys of weak gravitational lensing. It is argued that such an approach should be optimal, allowing measurement with maximal signal-to-noise ratio, coupled with estimation of measurement errors. The distinction between likelihood-based and Bayesian methods is discussed. Systematic biases in the Bayesian method may be evaluated as part of the fitting process, and overall such an approach should yield unbiased shear estimation without requiring external calibration from simulations. The principal disadvantage of model fitting for large surveys is the computational time required, but here an algorithm is presented that enables large surveys to be analysed in feasible computation times. The method and algorithm is tested on simulated galaxies from the Shear TEsting Programme (STEP).

Original languageEnglish
Pages (from-to)315-324
Number of pages10
JournalMonthly Notices of the Royal Astronomical Society
Volume382
Issue number1
DOIs
Publication statusPublished - 21 Nov 2007

Keywords

  • gravitational lensing
  • methods
  • data analysis
  • statistical
  • techniques
  • miscellaneous
  • HUBBLE-SPACE-TELESCOPE
  • COSMIC SHEAR
  • DARK ENERGY
  • CLUSTER
  • BARYONS
  • ANISOTROPY
  • MATTER

Fingerprint

Dive into the research topics of 'Bayesian galaxy shape measurement for weak lensing surveys - I. Methodology and a fast-fitting algorithm'. Together they form a unique fingerprint.

Cite this