A fully data-driven algorithm for accurate shear estimation
arXiv:2108.10057 · doi:10.1051/0004-6361/202141670
Abstract
Weak lensing by large-scale structure is a powerful probe of cosmology if the apparent alignments in the shapes of distant galaxies can be accurately measured. We study the performance of a fully data-driven approach, based on MetaDetection, focusing on the more realistic case of observations with an anisotropic PSF. Under the assumption that PSF anisotropy is the only source of additive shear bias, we show how unbiased shear estimates can be obtained from the observed data alone. To do so, we exploit the finding that the multiplicative shear bias obtained with MetaDetection is nearly insensitive to the PSF ellipticity. In practice, this assumption can be validated by comparing the empirical corrections obtained from observations to those from simulated data. We show that our data-driven approach meets the stringent requirements for upcoming space and ground-based surveys, although further optimisation is possible.
arXiv comment11 pages, accepted for publication in Astronomy and Astrophysics
References in corpus (33)
- Dark Energy Survey Year 1 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
- Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report
- Euclid Definition Study Report
- LSST Science Book, Version 2.0
- A Method for Weak Lensing Observations
- KiDS-1000 Cosmology: Cosmic shear constraints and comparison between two point statistics
- KiDS-1000 Cosmology: Multi-probe weak gravitational lensing and spectroscopic galaxy clustering constraints
- Dark Energy Survey Year 1 Results: Cosmological Constraints from Cosmic Shear
- Cosmology with cosmic shear observations: a review
- Shapes and Shears, Stars and Smears: Optimal Measurements for Weak Lensing
- GEMS: Galaxy Evolution from Morphologies and SEDs
- The Canadian Cluster Comparison Project: detailed study of systematics and updated weak lensing masses
- Weak lensing for precision cosmology
- Detection of weak lensing by a cluster of galaxies at z=0.83
- Practical Weak Lensing Shear Measurement with Metacalibration
- DES Y3 results: Blending shear and redshift biases in image simulations
- Metacalibration: Direct Self-Calibration of Biases in Shear Measurement
- Defining a weak lensing experiment in space
- The effect of imperfect corrections of PSF anisotropy on cosmic shear measurements
- Towards emulating cosmic shear data: Revisiting the calibration of the shear measurements for the Kilo-Degree Survey
- An improved model of Charge Transfer Inefficiency and correction algorithm for the Hubble Space Telescope
- A study of the sensitivity of shape measurements to the input parameters of weak lensing image simulations
- Euclid Preparation IV. Impact of undetected galaxies on weak-lensing shear measurements
- On the Probability Distributions of Ellipticity
- Mitigating Shear-dependent Object Detection Biases with Metacalibration
- On the shear estimation bias induced by the spatial variation of colour across galaxy profiles
- Weak-lensing shear measurement with machine learning: teaching artificial neural networks about feature noise
- Constraining the masses of high-redshift clusters with weak lensing: Revised shape calibration testing for the impact of stronger shears and increased blending
- Calibration of colour gradient bias in shear measurement using HST/CANDELS data
- Implications of a wavelength dependent PSF for weak lensing measurements
- Accounting for object detection bias in weak gravitational lensing studies
- Mitigating the effects of undersampling in weak lensing shear estimation with metacalibration
- Propagating Residual Biases in Cosmic Shear Power Spectra