Impact of blending on weak lensing measurements with the Legacy Survey of Space and Time

Fuente: arXiv
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Main Authors: Ramel, Manon, Doux, Cyrille, Kuna, Marine
Format: Preprint
Published: 2024
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author Ramel, Manon
Doux, Cyrille
Kuna, Marine
author_facet Ramel, Manon
Doux, Cyrille
Kuna, Marine
contents Upcoming deep optical surveys, such as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), will scan the sky to unprecedented depths, detecting billions of galaxies. However, this amount of detections will lead to the apparent superposition of galaxies in the images, a phenomenon known as blending, that can affect the accurate measurement of individual galaxy properties. In particular, galaxy shapes play a crucial role in estimating the masses of large-scale structures, such as galaxy clusters, through weak gravitational lensing. This proceeding introduces a new catalog matching algorithm, friendly, designed for detecting and characterizing blends in simulated LSST data for the Dark Energy Science Collaboration (DESC) Data Challenge 2. The aim of this algorithm is to combine several matching procedures, as well as a probabilistic method to quantify blended systems. By removing the resulted 27% of galaxies affected by blending from the dataset, we demonstrate that the amplitude of the excess surface mass density weak lensing profile - potentially biased low due to blending - may be partially corrected.
format Preprint
id arxiv_https___arxiv_org_abs_2412_02587
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Impact of blending on weak lensing measurements with the Legacy Survey of Space and Time
Ramel, Manon
Doux, Cyrille
Kuna, Marine
Cosmology and Nongalactic Astrophysics
Upcoming deep optical surveys, such as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), will scan the sky to unprecedented depths, detecting billions of galaxies. However, this amount of detections will lead to the apparent superposition of galaxies in the images, a phenomenon known as blending, that can affect the accurate measurement of individual galaxy properties. In particular, galaxy shapes play a crucial role in estimating the masses of large-scale structures, such as galaxy clusters, through weak gravitational lensing. This proceeding introduces a new catalog matching algorithm, friendly, designed for detecting and characterizing blends in simulated LSST data for the Dark Energy Science Collaboration (DESC) Data Challenge 2. The aim of this algorithm is to combine several matching procedures, as well as a probabilistic method to quantify blended systems. By removing the resulted 27% of galaxies affected by blending from the dataset, we demonstrate that the amplitude of the excess surface mass density weak lensing profile - potentially biased low due to blending - may be partially corrected.
title Impact of blending on weak lensing measurements with the Legacy Survey of Space and Time
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2412.02587