Origins of weak lensing systematics, and requirements on future instrumentation (or knowledge of instrumentation)

By Richard J. Massey, H. Hoekstra, Thomas D. Kitching, Jason D. Rhodes, M. Cropper, J. Amiaux, D. Harvey, Y. Mellier, Massimo Meneghetti, L. Miller and 4 more. 2012

142 citations recorded by the source corpus.

The first half of this paper explores the origin of systematic biases in the measurement of weak gravitational lensing. Compared to previous work, we expand the investigation of point spread function instability and fold in for the first time the effects of non-idealities in electronic imaging detectors and imperfect galaxy shape measurement algorithms. Together, these now explain the additive A(l) and multiplicative M(l) systematics typically reported in current lensing measurements. We find that overall performance is driven by a product of a telescope/camera's absolute performance, and our knowledge about its performance. The second half of this paper propagates any residual shear measurement biases through to their effect on cosmological parameter constraints. Fully exploiting the statistical power of Stage IV weak lensing surveys will require additive biasesA 1.8 × 10-12 and multiplicative biases M 4.0 × -3. These can be allocated between individual budgets in hardware, calibration data and software, using results from the first half of the paper. If instrumentation is stable and well calibrated, we find extant shear measurement software from Gravitational Lensing Accuracy Testing 2010 (GREAT10) already meet requirements on galaxies detected at signal-to-noise ratio = 40. Averaging over a population of galaxies with a realistic distribution of sizes, it also meets requirements for a 2D cosmic shear analysis from space. If used on fainter galaxies or for 3D cosmic shear tomography, existing algorithms would need calibration on simulations to avoid introducing bias at a level similar to the statistical error. Requirements on hardware and calibration data are discussed in more detail in a companion paper. Our analysis is intentionally general, but is specifically being used to drive the hardware and ground segment performance budget for the design of the European Space Agency's recently selected Euclid mission. ©2012 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/ae9ea07c4a2d82e70d0889b92cb790b352e77743

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Citations in the corpus

GalSim: The modular galaxy image simulation toolkit (2014, background): “…potential as a probe of cosmology, however, the weak lensing community must control additive and multiplicative systematic biases in shear estimates to ∼ 2 × 10 − 4 and 2 × 10 − 3 , respectively (e.g. al Réfrégier Huterer et ., 2006; Amara & , 2008; Massey et al., 2013; Mandelbaum et al., 2014).”
Gravitational lensing analysis of the Kilo-Degree Survey (2015, background): “Massey et al. (2013) present a compilation of possible sources of such correction terms, and calculate requirements on their amplitudes for different kinds of analysis.”
Galaxy Alignments: Observations and Impact on Cosmology (2015, background): “How various biases propagate was studied in detail in Massey et al. (2013).”
The first-year shear catalog of the Subaru Hyper Suprime-Cam Subaru Strategic Program Survey (2017, result): “The overall process described here is broadly consistent with that used for several ongoing and future surveys (Amara & Réfrégier 2008; Massey et al. 2013; Jarvis et al. 2016; Hildebrandt et al. 2017), differing only in small details of the implementation.”
The Canadian Cluster Comparison Project: detailed study of systematics and updated weak lensing masses (2015, background): “However, as discussed in e.g. Massey et al. (2013) and Semboloni et al. (2013), this complicates matters as the correction for the PSF now involves higher order moments, which themselves are affected by noise.”