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Weak gravitational lensing, the deflection of light by mass, is one of the best tools to constrain the growth of cosmic structure with time and reveal the nature of dark energy. I discuss the sources of systematic uncertainty in weak…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-17 Rachel Mandelbaum

We investigate cosmological parameter inference from realistic simulated weak lensing image data using only galaxy position angles, as opposed to full-ellipticity information. We demonstrate that input shear fields can be accurately…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-30 Lee Whittaker

Weak lensing alters the size of images with a similar magnitude to the distortion due to shear. Galaxy size probes the convergence field, and shape the shear field, both of which contain cosmological information. We show the gains expected…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Alan Heavens , Justin Alsing , Andrew Jaffe

We present a derivation of a generalized optimally-weighted estimator for the weak lensing magnification signal, including a calculation of errors. With this estimator, we present a local method for optimally estimating the local effects of…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Bryan Gillis , Andy Taylor

We have developed a new technique for weak lensing analysis, with which the effect of the point spread function (PSF) on small galaxy images can be corrected for accurately. Rather than relying on weighted second moments of detected images,…

Astrophysics · Physics 2016-08-30 Konrad Kuijken

(abridged) We review methods for measuring the sizes, line widths, and luminosities of giant molecular clouds (GMCs) in molecular-line data cubes with low resolution and sensitivity. We find that moment methods are robust and sensitive --…

Astrophysics · Physics 2008-11-26 Erik Rosolowsky , Adam Leroy

The COSMOS field has been the subject of a wide range of observations, with a number of studies focusing on reconstructing the 3D dark matter density field. Typically, these studies have focused on one given method or tracer. In this paper,…

Since gravitational lensing effects directly probe inhomogeneities of dark matter, lensing-galaxy cross-correlations can provide us important information on the relation between dark matter and galaxy distributions, i.e., the bias. In this…

Astrophysics · Physics 2009-11-10 Z. H. Fan

We present an extension of the multi-band galaxy fitting method scarlet which allows the joint modeling of astronomical images from different instruments, by performing simultaneous resampling and convolution. We introduce a fast and…

Instrumentation and Methods for Astrophysics · Physics 2021-07-16 Rémy Joseph , Peter Melchior , Fred Moolekamp

We propose a new approach for measuring the mass profile and shape of groups and clusters of galaxies, which uses lensing magnification of distant background galaxies. The main advantage of lensing magnification is that, unlike lensing…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Ludovic Van Waerbeke , Hendrik Hildebrandt , Jes Ford , Martha Milkeraitis

Context. The density split statistics in weak gravitational lensing analyses probes the correlation between regions of different (foreground) galaxy number densities and their weak lensing signal, measured by the shape distortion of…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-21 Pierre Burger , Peter Schneider , Vasiliy Demchenko , Joachim Harnois-Deraps , Catherine Heymans , Hendrik Hildebrandt , Sandra Unruh

Conventional approaches to cosmology inference from galaxy redshift surveys are based on n-point functions, which are under rigorous perturbative control on sufficiently large scales. Here, we present an alternative approach, which employs…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-23 Fabian Schmidt , Franz Elsner , Jens Jasche , Nhat Minh Nguyen , Guilhem Lavaux

The Six Degree Field Galaxy Survey (6dFGS) is a spectroscopic survey of the southern sky, which aims to provide positions and velocities of galaxies in the nearby Universe. We present here the adaptive tiling algorithm developed to place…

Astrophysics · Physics 2011-03-10 Lachlan Campbell , Will Saunders , Matthew Colless

We describe and test the pipeline used to measure the weak lensing shear signal from the Kilo Degree Survey (KiDS). It includes a novel method of `self-calibration' that partially corrects for the effect of noise bias. We also discuss the…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Ian Fenech Conti , Ricardo Herbonnet , Henk Hoekstra , Julian Merten , Lance Miller , Massimo Viola

Measuring dark matter substructure within galaxy cluster haloes is a fundamental probe of the Lambda-CDM model of structure formation. Gravitational lensing is a technique for measuring the total mass distribution which is independent of…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-17 Benjamin Cain , Paul L. Schechter , M. W. Bautz

We present the results of fitting simulations of an unbiased sample of SDSS galaxies utilizing the fitting routine GALFIT and analysis pipeline PyMorph. These simulations are used to test the two-dimensional decompositions of SDSS galaxies.…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-10 Alan Meert , Vinu Vikram , Mariangela Bernardi

In this paper, we develop a new gravitational lensing inversion technique. While traditional approaches assume that the lensing field varies little across a galaxy image, we note that this variation in the field can give rise to a…

Astrophysics · Physics 2009-11-10 David M. Goldberg , David J. Bacon

This paper extends the method introduced in Rivi et al. (2016b) to measure galaxy ellipticities in the visibility domain for radio weak lensing surveys. In that paper we focused on the development and testing of the method for the simple…

Instrumentation and Methods for Astrophysics · Physics 2018-04-16 Marzia Rivi , Lance Miller

Characterization of the morphology of strongly lensed galaxies is challenging because images of such galaxies are typically highly distorted. Lens modeling and source plane reconstruction is one approach that can provide reasonably…

Astrophysics of Galaxies · Physics 2016-12-14 Michael K. Florian , Nan Li , Michael D. Gladders

Studies of strong gravitational lensing in current and upcoming wide and deep photometric surveys, and of stellar kinematics from (integral-field) spectroscopy at increasing redshifts, promise to provide valuable constraints on galaxy…

Astrophysics · Physics 2015-05-13 Glenn van de Ven , Rachel Mandelbaum , Charles R. Keeton