Melanie Simet

THE THIRD GRAVITATIONAL LENSING ACCURACY TESTING (GREAT3) CHALLENGE HANDBOOK

The GRavitational lEnsing Accuracy Testing 3 (GREAT3) challenge is the third in a series of image analysis challenges, with a goal of testing and facilitating the development of methods for analyzing astronomical images that will be used to measure weak gravitational lensing. This measurement requires extremely precise estimation of very small galaxy shape distortions, in the presence of far larger intrinsic galaxy shapes and distortions due to the blurring kernel caused by the atmosphere, telescope optics, and instrumental effects. The GREAT3 challenge is posed to the astronomy, machine learning, and statistics communities, and includes tests of three specific effects that are of immediate relevance to upcoming weak lensing surveys, two of which have never been tested in a community challenge before. These effects include many novel aspects including realistically complex galaxy models based on high-resolution imaging from space; a spatially varying, physically motivated blurring kernel; and a combination of multiple different exposures. To facilitate entry by people new to the field, and for use as a diagnostic tool, the simulation software for the challenge is publicly available, though the exact parameters used for the challenge are blinded. Sample scripts to analyze the challenge data using existing methods will also be provided. See http://great3challenge.info and http://great3.projects.phys.ucl.ac.uk/leaderboard/ for more information.

Weak Lensing Measurement of the Mass--Richness Relation of SDSS redMaPPer Clusters

DOE [DE-AC02-98CH10886]; US Department of Energy [DE-AC02-76SF00515]; National Science Foundation [NSF-AST-1211838]; Alfred P. Sloan Foundation; National Science Foundation; US Department of Energy Office of Science; Department of Energy Early Career Award program; University of Arizona; Brazilian Participation Group; Brookhaven National Laboratory; Carnegie Mellon University; University of Florida; French Participation Group; German Participation Group; Harvard University; Instituto de Astrofisica de Canarias; Michigan State/Notre Dame/JINA Participation Group; Johns Hopkins University; Lawrence Berkeley National Laboratory; Max Planck Institute for Astrophysics; Max Planck Institute for Extraterrestrial Physics; New Mexico State University; New York University; Ohio State University; Pennsylvania State University; University of Portsmouth; Princeton University; Spanish Participation Group; University of Tokyo; University of Utah; Vanderbilt University; University of Virginia; University of Washington; Yale University

On the Level of Cluster Assembly Bias in SDSS

Recently, several studies have discovered a strong discrepancy between the large-scale clustering biases of two subsamples of galaxy clusters at the same halo mass, split by their average projected membership distances

Weak lensing calibration of mass bias in the REFLEX+BCS X-ray galaxy cluster catalogue

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Background sky obscuration by cluster galaxies as a source of systematic error for weak lensing

. The level of this discrepancy significantly exceeds the maximum halo assembly bias signal predicted by LCDM. In this study, we explore whether some of the clustering bias differences could be caused by biases in

The first-year shear catalog of the Subaru Hyper Suprime-Cam Subaru Strategic Program Survey

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Source Selection for Cluster Weak Lensing Measurements in the Hyper Suprime-Cam Survey

due to projection effects from other systems along the line-of-sight. We thoroughly investigate the halo assembly bias of the photometrically-detected redMaPPer clusters in SDSS, by defining a new variant of the average membership distance estimator

A Unified Analysis of Four Cosmic Shear Surveys

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GalSim: The modular galaxy image simulation toolkit

that is more robust against projection effects in the cluster membership identification. Using the angular mark correlation functions of clusters, we show that the large-scale bias differences when splitting by

GREAT3 results - I. Systematic errors in shear estimation and the impact of real galaxy morphology

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