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Related papers: A Method To Characterize the Wide-Angle Point Spre…

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We describe the time- and position-dependent point spread function (PSF) variation of the Wide Field Channel (WFC) of the Advanced Camera for Surveys (ACS) with the principal component analysis (PCA) technique. The time-dependent change is…

Astrophysics · Physics 2009-11-13 M. J. Jee , J. P. Blakeslee , M. Sirianni , A. R. Martel , R. L. White , H. C. Ford

In this work we derive analytic expressions and numerical recipes for finding the effective observed position of sources close enough on sky that their Point Spread Functions (PSF), modelled as Gaussian profiles, overlap. In particularly we…

Solar and Stellar Astrophysics · Physics 2026-03-24 Zephyr Penoyre

Measuring the integrated stellar halo light around galaxies is very challenging. The surface brightness of these haloes are expected to be many magnitudes below dark sky and the central brightness of the galaxy. Here I show that in some of…

Astrophysics · Physics 2009-11-13 Roelof S. de Jong

The spectral energy distribution (SED) of observed stars in wide-field images is crucial for chromatic point spread function (PSF) modelling methods, which use unresolved stars as integrated spectral samples of the PSF across the field of…

Instrumentation and Methods for Astrophysics · Physics 2025-02-19 Ezequiel Centofanti , Samuel Farrens , Jean-Luc Starck , Tobias Liaudat , Alex Szapiro , Jennifer Pollack

The point-spread function (PSF) of an adaptive optics (AO) system is often poorly known. This ignorance can lead to significant systematic errors in photometry. Since the degree of AO correction is sensitive to the observing conditions:…

Astrophysics · Physics 2010-11-11 Christopher D. Sheehy , Nate McCrady , James R. Graham

Image subtraction is essential for transient detection in time-domain astronomy. The point spread function (PSF), photometric scaling, and sky background generally vary with time and across the field-of-view for imaging data taken with…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 Lei Hu , Lifan Wang , Xingzhuo Chen , Jiawen Yang

The Chinese Space Station Survey Telescope (CSST) presents significant potential for high-precision astrometry. In this study, we show that the point spread function (PSF) modeled by the discrete PSF with Multi-Gaussian function can…

Instrumentation and Methods for Astrophysics · Physics 2025-08-15 Jialu Nie , Peng Wei , Zihuang Cao , Yibo Yan , Chao Liu , Hao Tian , Xin Zhang , Haijun Tian

Context. Accurate photometry with ground based solar telescopes requires characterization of straylight. Scattering in Earth's atmosphere and in the telescope optics are potentially significant sources of straylight, for which the point…

Solar and Stellar Astrophysics · Physics 2016-01-13 Mats G. Löfdahl

Incoherently illuminated or luminescent objects give rise to a low-contrast speckle-like pattern when observed through a thin diffusive medium, as such a medium effectively convolves their shape with a speckle-like point spread function…

Anisoplanatic effects can cause significant systematic photometric uncertainty in the analysis of dense stellar fields observed with adaptive optics. Program packages have been developed for a spatially variable PSF, but they require that a…

Instrumentation and Methods for Astrophysics · Physics 2009-12-08 R. Schoedel

Direct imaging of exoplanets is limited by bright quasi-static speckles in the point spread function (PSF) of the central star. This limitation can be reduced by subtraction of reference PSF images. We have developed an algorithm to…

Astrophysics · Physics 2011-02-11 David Lafreniere , Christian Marois , Rene Doyon , Daniel Nadeau , Etienne Artigau

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

The ability to accurately measure the shapes of faint objects in images taken with the Advanced Camera for Surveys(ACS) on the Hubble Space Telescope (HST) depends upon detailed knowledge of the Point Spread Function (PSF). We show that…

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…

Instrumentation and Methods for Astrophysics · Physics 2024-03-25 Claire-Alice Hébert , Joshua E. Meyers , My H. Do , Patricia R. Burchat , the LSST Dark Energy Science Collaboration

We investigate the impact of point spread function (PSF) fitting errors on cosmic shear measurements using the concepts of complexity and sparsity. Complexity, introduced in a previous paper, characterizes the number of degrees of freedom…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 S. Paulin-Henriksson , A. Refregier , A. Amara

Imaging with a layered superlens is a spatial filtering operation characterized by the point spread function (PSF). We show that in the same optical system the image of a narrow sub-wavelength Gaussian incident field may be surprisingly…

Optics · Physics 2010-04-08 Rafal Kotynski , Tomasz Stefaniuk

We present a new technique for monitoring microlensing activity even in highly crowded fields, and use this technique to place limits on low-mass MACHOs in the haloes of M31 and the Galaxy. Unlike present Galactic microlensing surveys, we…

Astrophysics · Physics 2009-09-28 Austin B. Tomaney , Arlin P. S. Crotts

(abridged) We examine the spatial and temporal stability of the HST ACS Wide Field Camera (WFC) point spread function (PSF) using the two square degree COSMOS survey. We show that stochastic aliasing of the PSF necessarily occurs during…

The point-spread function (PSF) is a fundamental property of any astronomical instrument. In interferometers, differing array configurations combined with their $uv$ coverage, and various weighting schemes can produce an irregular but…

Instrumentation and Methods for Astrophysics · Physics 2023-10-20 Jack F. Radcliffe , R. J. Beswick , A. P. Thomson , A. Njeri , T. W. B. Muxlow

The Surface Brightness Fluctuations (SBF) Method for distance determinations of elliptical galaxies is been modeled in order to investigate the effect of the Point Spread Function (PSF). We developed a method to simulate observations of SBF…

Astrophysics · Physics 2012-07-23 D. Gouliermis , W. Brandner , D. Butler , S. Hippler