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Shapelets “Multiple Multipole” Shear Measurement

Massey, Richard and Refregier, Alexandre and Bacon, David (2005) Shapelets “Multiple Multipole” Shear Measurement. In: Impact of Gravitional Lensing on Cosmology. IAU Symposia . No.225. Cambridge University Press , Cambridge, U.K., pp. 31-36. ISBN 978-0-521-85196-1.

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The measurement of weak gravitational lensing is currently limited to a precision of ~ 10% by instabilities in galaxy shape measurement techniques and uncertainties in their calibration. The potential of large, on-going and future cosmic shear surveys will only be realised with the development of more accurate image analysis methods. We present a description of several possible shear measurement methods using the linear “shapelets” decomposition. Shapelets provides a complete reconstruction of any galaxy image, including higher-order shape moments that can be used to generalise the KSB method to arbitrary order. Many independent shear estimators can then be formed for each object, using linear combinations of shapelet coefficients. These estimators can be treated separately, to improve their overall calibration; or combined in more sophisticated ways, to eliminate various instabilities and a calibration bias. We apply several methods to simulated astronomical images containing a known input shear, and demonstrate the dramatic improvement in shear recovery using shapelets. A complete IDL software package to perform image analysis and manipulation in shapelet space can be downloaded from

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Additional Information:© 2004 International Astronomical Union. The authors are pleased to thank Joel Bergé, Alain Boinissent, Tzu-Ching Chang, Dave Goldberg, Will High, Konrad Kuijken and Molly Peeples for helpful discussions.
Series Name:IAU Symposia
Issue or Number:225
Record Number:CaltechAUTHORS:20110819-112956547
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Official Citation:Shapelets “Multiple Multipole” Shear Measurement Richard Massey, Alexandre Refregier and David Bacon Proceedings of the International Astronomical Union / Volume 2004 / Issue IAUS225, pp 31 - 36 2004 International Astronomical Union Published online: 15 June 2005 DOI:10.1017/S1743921305001766
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:24959
Deposited By: Ruth Sustaita
Deposited On:19 Aug 2011 18:49
Last Modified:03 Oct 2019 03:01

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