Results 101 to 110 of about 206 (178)

D4CNN×AnaCal: Physics-informed Machine Learning for Accurate and Precise Weak-lensing Shear Estimation

The Astrophysical Journal
Traditional weak-gravitational-lensing shear estimators are carefully calibrated but struggle to fully capture realistic galaxy morphologies, point-spread-function (PSF) effects, blending, and noise in deep surveys, while blindly trained machine learning
Shurui Lin, Xiangchong Li, Ji Li, Shengcao Cao, Xin Liu, Yu-Xiong Wang   +5 more
doaj   +1 more source

A New Method for PSF correction using the Ellipticity of Re-smeared Artificial Images in Weak Gravitational Lensing Shear Analysis

, 2014
We propose a new method for Point Spread Function (PSF) correction in weak gravitational lensing shear analysis using an artificial image with the same ellipticity as the lensed image. This avoids the systematic error associated with the approximation in PSF correction used in previous approaches.
Okura, Yuki, Futamase, Toshifumi
openaire   +2 more sources

Generation of realistic input parameters for simulating atmospheric point-spread functions at astronomical observatories

The Open Journal of Astrophysics
High-fidelity simulated astronomical images are an important tool in developing and measuring the performance of image-processing algorithms, particularly for high precision measurements of cosmic shear -- correlated distortions of images of distant ...
Claire-Alice Hébert, Joshua E. Meyers, My H. Do, Patricia R. Burchat, LSST Dark Energy Science Collaboration   +4 more
doaj   +1 more source

Weak gravitational lensing measurements of Abell 2744 using JWST and shear measurement algorithm pyRRG-JWST

Monthly Notices of the Royal Astronomical Society
ABSTRACT We update the publicly available weak lensing shear measurement algorithm pyRRG for the JWST, and apply it to UNCOVER DR1 imaging of galaxy cluster Abell 2744. At short wavelengths (${\lt}2.5\, \mu$m), shear measurements are consistent between independent observations through different JWST bandpasses, and calibrated within 1.5 ...
David R Harvey, Richard Massey
openaire   +3 more sources

Galaxy–Galaxy Lensing Data: f(T) Gravity Challenges General Relativity

The Astrophysical Journal
We use galaxy–galaxy lensing data to test general relativity and f ( T ) gravity at galaxy scales. We consider an exact spherically symmetric solution of f ( T ) theory, which is obtained from an approximate quadratic correction, and thus it is expected ...
Qingqing Wang, Xin Ren, Bo Wang, Yi-Fu Cai, Wentao Luo, Emmanuel N. Saridakis   +5 more
doaj   +1 more source

Encoding Collective Knowledge, Instructing Data Reusers: The Collaborative Fixation of a Digital Scientific Data Set. [PDF]

Comput Support Coop Work, 2021
Hoeppe G.
europepmc   +1 more source

Simulating Image Coaddition with the Nancy Grace Roman Space Telescope. IV. Hyperparameter Optimization and Experimental Features

The Astrophysical Journal
For weak gravitational lensing cosmology with the forthcoming Nancy Grace Roman Space Telescope, image coaddition (or construction of oversampled images from undersampled ones) is a critical step in the image processing pipeline.
Kaili Cao, Christopher M. Hirata, Katherine Laliotis, Masaya Yamamoto, Emily Macbeth, M. A. Troxel, (Roman HLIS Cosmology PIT)   +6 more
doaj   +1 more source

Supermassive Dark Star candidates seen by JWST. [PDF]

Proc Natl Acad Sci U S A, 2023
Ilie C, Paulin J, Freese K.
europepmc   +1 more source

Low-redshift Analogs of Cosmic Noon Galaxies as Laboratories for Clumpy Star Formation

The Astrophysical Journal
It has been established that a significant fraction of star formation at high redshift occurs in clumpy galaxies. The properties of clumps and their formation mechanisms, however, remain highly debated. In this work we analyze a sample of 18 supercompact
Jorge M. Santos-Junior, Thiago S. Gonçalves, Luidhy Santana-Silva, Arianna Cortesi, Karin Menendez-Delmestre, Amanda E. Araujo-Carvalho   +5 more
doaj   +1 more source

Detection of early-universe gravitational-wave signatures and fundamental physics. [PDF]

Gen Relativ Gravit, 2022
Caldwell R, Cui Y, Guo HK, Mandic V, Mariotti A, No JM, Ramsey-Musolf MJ, Sakellariadou M, Sinha K, Wang LT, White G, Zhao Y, An H, Bian L, Caprini C, Clesse S, Cline JM, Cusin G, Fornal B, Jinno R, Laurent B, Levi N, Lyu KF, Martinez M, Miller AL, Redigolo D, Scarlata C, Sevrin A, Haghi BSE, Shu J, Siemens X, Steer DA, Sundrum R, Tamarit C, Weir DJ, Xie KP, Yang FW, Zhou S.   +37 more
europepmc   +1 more source