English
Related papers

Related papers: Stellar Photometry and Astrometry with Discrete Po…

200 papers

With the arrival of the next generation of ultra-deep optical imaging surveys reaching $\mu_V$$\sim$30 mag/arcsec$^2$ (3$\sigma$; 10"$\times$10"), the removal of scattered light due to the point spread function (PSF) effect remains a…

Weak gravitational lensing requires precise measurements of galaxy shapes and therefore an accurate knowledge of the PSF model. The latter can be a source of systematics that affect the shear two-point correlation function. A key stake of…

Current Point-based detectors can only learn from the provided points, with limited receptive fields and insufficient global learning capabilities for such targets. In this paper, we present a novel Point Dilation Mechanism for single-stage…

Computer Vision and Pattern Recognition · Computer Science 2025-02-13 Ao Liang , Haiyang Hua , Jian Fang , Wenyu Chen , Huaici Zhao

HSTphot, a photometry package designed to handle the undersampled PSFs found in WFPC2 images, is introduced and described, as well as some of the considerations that have to be made in order to obtain accurate PSF-fitting stellar photometry…

Astrophysics · Physics 2009-05-29 Andrew E. Dolphin

Difference imaging or image subtraction is a method that measures differential photometry by matching the pointing and point-spread function (PSF) between image frames. It is used for the detection of time-variable phenomena. Here we…

Instrumentation and Methods for Astrophysics · Physics 2017-10-10 Dun Wang , David W. Hogg , Daniel Foreman-Mackey , Bernhard Schölkopf

(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…

Images from adaptive optics systems are generally affected by significant distortions of the point spread function (PSF) across the field of view, depending on the position of natural and artificial guide stars. Image reduction techniques…

Instrumentation and Methods for Astrophysics · Physics 2015-06-24 Andrea La Camera , Laura Schreiber , Emiliano Diolaiti , Patrizia Boccacci , Mario Bertero , Michele Bellazzini , Paolo Ciliegi

Photometric redshifts (photo-z's) provide an alternative way to estimate the distances of large samples of galaxies and are therefore crucial to a large variety of cosmological problems. Among the various methods proposed over the years,…

Instrumentation and Methods for Astrophysics · Physics 2017-06-13 Stefano Cavuoti , Massimo Brescia , Valeria Amaro , Civita Vellucci , Giuseppe Longo , Crescenzo Tortora

Observations close to the diffraction limit, with high Strehl ratios from Adaptive Optics (AO)-assisted instruments mounted on ground-based telescopes are a reality and will become even more widespread with the next generation instruments…

Instrumentation and Methods for Astrophysics · Physics 2023-10-23 Matteo Simioni , Carmelo Arcidiacono , Andrea Grazian , Marco Gullieuszik , Elisa Portaluri , Benedetta Vulcani , Roland Wagner , Anita Zanella

In single-molecule super-resolution microscopy, engineered point-spread functions (PSFs) are designed to efficiently encode new molecular properties, such as 3D orientation, into complex spatial features captured by a camera. To fully…

Image and Video Processing · Electrical Eng. & Systems 2019-07-16 Hesam Mazidi , Eshan S. King , Oumeng Zhang , Arye Nehorai , Matthew D. Lew

Point-spread function of the probe forming optics ($PSF_{optics} $) is reported for the first time in an uncorrected (without multipole correctors) scanning electron microscope (SEM). In an SEM, the electron probe information is lost as the…

Materials Science · Physics 2024-07-02 Surya Kamal , Richard K. Hailstone

The control of systematic effects when measuring galaxy shapes is one of the main challenges for cosmic shear analyses. In this context, we study the fundamental limitations on shear accuracy due to the measurement of the Point Spread…

Astrophysics · Physics 2009-11-13 S. Paulin-Henriksson , A. Amara , L. Voigt , A. Refregier , S. L. Bridle

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

Context. The knowledge of the point-spread function compensated by adaptive optics is of prime importance in several image restoration techniques such as deconvolution and astrometric/photometric algorithms. Wavefront-related data from the…

Astrophysics · Physics 2016-08-15 Eric Gendron , Yann Clénet , Thierry Fusco , Gérard Rousset

The Transiting Exoplanet Survey Satellite (TESS, launched early 2018) is expected to find a multitude of new transiting planet candidates around the nearest and brightest stars. Timely high-precision follow-up observations from the ground…

Instrumentation and Methods for Astrophysics · Physics 2018-08-08 Gudmundur Stefansson , Suvrath Mahadevan , John Wisniewski , Yiting Li , Marissa Maney , Leslie Hebb , Brett Morris , Samuel Halverson , Andrew Monson , Paul Robertson

We present a method of centroiding undersampled point spread functions (PSFs) that may be useful, especially when dithering is not an option. If the profile of the expected PSF is known fairly well through characterization of the telescope…

Instrumentation and Methods for Astrophysics · Physics 2025-03-05 Kevin J. Ludwick , Ashley Mazingo

The weak gravitational lensing is a powerful tool in modern cosmology. To accurately measure the weak lensing signal, one has to control the systematic bias to a small level. One of the most difficult problems is how to correct the smearing…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-28 Q. Y. Liu , X. Z. Er , Z. H. Fan , D. Z. Liu , G. L. Li , C. L. Wei , Z. Ban , X. B. Li , D. Yue

Neural posterior estimation (NPE), a type of amortized variational inference, is a computationally efficient means of constructing probabilistic catalogs of light sources from astronomical images. To date, NPE has not been used to perform…

Instrumentation and Methods for Astrophysics · Physics 2025-08-26 Aakash Patel , Tianqing Zhang , Camille Avestruz , Jeffrey Regier , the LSST Dark Energy Science Collaboration

We present an analysis of six independent on-sky datasets taken with the Keck-II/NIRC2 instrument. Using the off-axis point spread function (PSF) reconstruction software AIROPA, we extract stellar astrometry, photometry, and other fitting…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 Sean K. Terry , Jessica R. Lu , Paolo Turri , Anna Ciurlo , Abhimat Gautam , Tuan Do , Michael P. Fitzgerald , Andrea Ghez , Matthew Hosek , Gunther Witzel