Results 121 to 130 of about 1,077 (214)
The Astrophysical Journal, 2002 Studies of weak gravitational lensing by large-scale structures require the measurement of the distortions introduced to the shapes of distant galaxies at the few percent level by anisotropic light deflection along the line of sight. To detect this signal on 1-10 arcmin scales in a particular field, accurate measurements of the correlations between the
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The Open Journal of AstrophysicsHigh-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 +4 more
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FLAMINGO: calibrating large cosmological hydrodynamical simulations with machine learning. [PDF]
Mon Not R Astron Soc, 2023 Kugel R +19 more
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Galaxy–Galaxy Lensing Data: f(T) Gravity Challenges General Relativity
The Astrophysical JournalWe 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 +5 more
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Monthly Notices of the Royal Astronomical SocietyABSTRACT 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
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Weak gravitational shear and flexion with polar shapelets
, 2007 We derive expressions, in terms of ‘polar shapelets’, for the image distortion operations associated with weak gravitational lensing. Shear causes galaxy shapes to become elongated, and is sensitive to the second derivative of the projected gravitational
Massey, Richard +9 more
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The Astrophysical JournalFor 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 +6 more
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Low-redshift Analogs of Cosmic Noon Galaxies as Laboratories for Clumpy Star Formation
The Astrophysical JournalIt 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 +5 more
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Encoding Collective Knowledge, Instructing Data Reusers: The Collaborative Fixation of a Digital Scientific Data Set. [PDF]
Comput Support Coop Work, 2021 Hoeppe G.
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