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Strong gravitational lensing offers a powerful probe of the detailed distribution of matter in lenses, while magnifying and bringing faint background sources into view. Observed strong lensing by massive galaxy clusters, which are often in…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-29 Yarone M. Tokayer , Isaque Dutra , Priyamvada Natarajan , Guillaume Mahler , Mathilde Jauzac , Massimo Meneghetti

Galaxy-galaxy lensing is rapidly becoming one of the most promising means to accurately measure the average relation between galaxy properties and halo mass. In order to obtain a signal of sufficient signal-to-noise, one needs to stack many…

Quantifying image distortions caused by strong gravitational lensing and estimating the corresponding matter distribution in lensing galaxies has been primarily performed by maximum likelihood modeling of observations. This is typically a…

Instrumentation and Methods for Astrophysics · Physics 2017-09-20 Yashar D. Hezaveh , Laurence Perreault Levasseur , Philip J. Marshall

In the last decade the detection of individual massive dark matter sub-halos has been possible using potential correction formalism in strong gravitational lens imaging. Here we propose a statistical formalism to relate strong gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-17 Saikat Chatterjee , Léon V. E. Koopmans

A fundamental prediction of the cold dark matter cosmology is the existence of a large number of dark subhalos around galaxies, most of which should be entirely devoid of stars. Confirming the existence of dark substructures stands among…

Astrophysics of Galaxies · Physics 2018-08-01 Andrew S. Graus , James S. Bullock , Michael Boylan-Kolchin , Anna M. Nierenberg

Current theories of structure formation predict specific density profiles of galaxy dark matter haloes, and with weak gravitational lensing we can probe these profiles on several scales. On small scales, higher-order shape distortions known…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Malin Velander , Konrad Kuijken , Tim Schrabback

Image segmentation is the task of associating pixels in an image with their respective object class labels. It has a wide range of applications in many industries including healthcare, transportation, robotics, fashion, home improvement,…

Computer Vision and Pattern Recognition · Computer Science 2023-01-19 Yuanbo Wang , Unaiza Ahsan , Hanyan Li , Matthew Hagen

Strong gravitational lensing can be used to find otherwise invisible dark matter subhaloes. In such an analysis, the lens galaxy mass model is a significant source of systematic uncertainty. In this paper we analyse the effect of angular…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-15 Conor M. O'Riordan , Simona Vegetti

Many distant objects can only be detected, or become more scientifically valuable, if they have been highly magnified by strong gravitational lensing. We use EAGLE and BAHAMAS, two recent cosmological hydrodynamical simulations, to predict…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-03 Andrew Robertson , Graham P. Smith , Richard Massey , Vincent Eke , Mathilde Jauzac , Matteo Bianconi , Dan Ryczanowski

We rederive the number density of intervening line-of-sight haloes relative to lens subhaloes in galaxy-galaxy strong lensing observations, where these perturbers can generate detectable image fluctuations. Previous studies have calculated…

The gravitational lensing of supermassive black holes surrounded by dark matter halo has attracted a great number of interests in recent years. However, many studies employed simplified dark matter density models, which makes it very hard…

General Relativity and Quantum Cosmology · Physics 2024-10-25 Yi-Gao Liu , Chen-Kai Qiao , Jun Tao

In these lectures I give an overview of gravitational lensing, concentrating on theoretical aspects, including derivations of some of the important results. Topics covered include the determination of surface mass densities of intervening…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-08 Alan Heavens

We describe a new method for analyzing gravitational lens images, for the case where the source light distribution is pixelized. The method is suitable for high resolution, high S/N data of a multiply-imaged extended source. For a given…

Astrophysics · Physics 2009-11-07 Steve Warren , Simon Dye

Fully supervised deep neural networks for segmentation usually require a massive amount of pixel-level labels which are manually expensive to create. In this work, we develop a multi-task learning method to relax this constraint. We regard…

Computer Vision and Pattern Recognition · Computer Science 2021-04-07 Rihuan Ke , Aurélie Bugeau , Nicolas Papadakis , Mark Kirkland , Peter Schuetz , Carola-Bibiane Schönlieb

Analysing the weak lensing distortions of the images of faint background galaxies provides a means to constrain the average mass distribution of cluster galaxies and potentially to test the extent of their dark matter haloes as a function…

Astrophysics · Physics 2009-10-30 Bernhard Geiger , Peter Schneider

The spatial distribution of compact dark matter in our Galaxy can be determined in a few years of monitoring Galactic globular clusters for microlensing. Globular clusters are the only dense fields of stars distributed throughout the…

Astrophysics · Physics 2009-10-30 James E. Rhoads , Sangeeta Malhotra

It has been shown by Paczy\'nski that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in the approximate domain $10^{-6} < M/M_{\odot} < 10^{-1}$.…

Astrophysics · Physics 2008-02-03 Philippe Jetzer

We present a reconstructions of galaxy-cluster-scale mass distributions from simulated gravitational lensing data sets including strong lensing, weak lensing shear, and measurements of quadratic image distortions -- flexion. The lensing…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Benjamin Cain , Marusa Bradac , Rebecca Levinson

Image segmentation plays a critical role in unlocking the mysteries of the universe, providing astronomers with a clearer perspective on celestial objects within complex astronomical images and data cubes. Manual segmentation, while…

Instrumentation and Methods for Astrophysics · Physics 2024-05-24 Duo Xu , Ye Zhu

Gravitational lensing is a powerful astrophysical and cosmological probe and is particularly valuable at submillimeter wavelengths for the study of the statistical and individual properties of dusty starforming galaxies. However the…