Prof Richard Massey r.j.massey@durham.ac.uk
Professor
The shear testing programme 2 : Factors affecting high-precision weak-lensing analyses
Massey, R.; Heymans, C.; Bergé, J.; Bernstein, G.; Bridle, S.; Clowe, D.; Dahle, H.; Ellis, R.; Erben, T.; Hetterscheidt, M.; High, F.W.; Hirata, C.; Hoekstra, H.; Hudelot, P.; Jarvis, M.; Johnston, D.; Kuijken, K.; Margoniner, V.; Mandelbaum, R.; Mellier, Y.; Nakajima, R.; Paulin-Henriksson, S.; Peeples, M.; Roat, C.; Refregier, A.; Rhodes, J.; Schrabback, T.; Schirmer, M.; Seljak, U.; Semboloni, E.; Van Waerbeke, L.
Authors
C. Heymans
J. Bergé
G. Bernstein
S. Bridle
D. Clowe
H. Dahle
R. Ellis
T. Erben
M. Hetterscheidt
F.W. High
C. Hirata
H. Hoekstra
P. Hudelot
M. Jarvis
D. Johnston
K. Kuijken
V. Margoniner
R. Mandelbaum
Y. Mellier
R. Nakajima
S. Paulin-Henriksson
M. Peeples
C. Roat
A. Refregier
J. Rhodes
T. Schrabback
M. Schirmer
U. Seljak
E. Semboloni
L. Van Waerbeke
Abstract
The Shear Testing Programme (STEP) is a collaborative project to improve the accuracy and reliability of weak-lensing measurement, in preparation for the next generation of wide-field surveys. We review 16 current and emerging shear-measurement methods in a common language, and assess their performance by running them (blindly) on simulated images that contain a known shear signal. We determine the common features of algorithms that most successfully recover the input parameters. A desirable goal would be the combination of their best elements into one ultimate shear-measurement method. In this analysis, we achieve previously unattained discriminatory precision via a combination of more extensive simulations and pairs of galaxy images that have been rotated with respect to each other. That removes the otherwise overwhelming noise from their intrinsic ellipticities. Finally, the robustness of our simulation approach is confirmed by testing the relative calibration of methods on real data. Weak-lensing measurements have improved since the first STEP paper. Several methods now consistently achieve better than 2 per cent precision, and are still being developed. However, we can now distinguish all methods from perfect performance. Our main concern continues to be the potential for a multiplicative shear calibration bias: not least because this cannot be internally calibrated with real data. We determine which galaxy populations are responsible for bias and, by adjusting the simulated observing conditions, we also investigate the effects of instrumental and atmospheric parameters. The simulated point spread functions are not allowed to vary spatially, to avoid additional confusion from interpolation errors. We have isolated several previously unrecognized aspects of galaxy shape measurement, in which focused development could provide further progress towards the sub-per cent level of precision desired for future surveys. These areas include the suitable treatment of image pixellization and galaxy morphology evolution. Ignoring the former effect affects the measurement of shear in different directions, leading to an overall underestimation of shear and hence the amplitude of the matter power spectrum. Ignoring the second effect could affect the calibration of shear estimators as a function of galaxy redshift, and the evolution of the lensing signal, which will be vital to measure parameters including the dark energy equation of state.
Citation
Massey, R., Heymans, C., Bergé, J., Bernstein, G., Bridle, S., Clowe, D., …Van Waerbeke, L. (2007). The shear testing programme 2 : Factors affecting high-precision weak-lensing analyses. Monthly Notices of the Royal Astronomical Society, 376(1), 13-38. https://doi.org/10.1111/j.1365-2966.2006.11315.x
Journal Article Type | Article |
---|---|
Publication Date | Mar 21, 2007 |
Deposit Date | Mar 21, 2013 |
Publicly Available Date | Mar 29, 2024 |
Journal | Monthly Notices of the Royal Astronomical Society |
Print ISSN | 0035-8711 |
Electronic ISSN | 1365-2966 |
Publisher | Royal Astronomical Society |
Peer Reviewed | Peer Reviewed |
Volume | 376 |
Issue | 1 |
Pages | 13-38 |
DOI | https://doi.org/10.1111/j.1365-2966.2006.11315.x |
Keywords | Gravitational lensing, Methods: data analysis, Cosmology: observations. |
Files
Published Journal Article
(1.1 Mb)
PDF
Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2007 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
You might also like
Scanning for dark matter subhaloes in Hubble Space Telescope imaging of 54 strong lenses
(2023)
Journal Article
Data Downloaded via Parachute from a NASA Super-Pressure Balloon
(2023)
Journal Article
A Recent Impact Origin of Saturn’s Rings and Mid-sized Moons
(2023)
Journal Article
RXJ0437+00: constraining dark matter with exotic gravitational lenses
(2023)
Journal Article
Downloadable Citations
About Durham Research Online (DRO)
Administrator e-mail: dro.admin@durham.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search