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Related papers: Representations of celestial coordinates in FITS

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Spherometer is an instrument widely used for measuring the radius of curvature of a spherical surface. Cylindrometer is a modified spherometer, which can measure the radii of both spherical and cylindrical surfaces. Both of these…

General Physics · Physics 2013-11-15 Sameen Ahmed Khan

We present a novel orbit parameterization in spherical coordinates. This parameterization enables the mixing of varying and invariant orbital parameters, and clarifies the physics of the orbit. It also simplifies the process of placing…

Earth and Planetary Astrophysics · Physics 2024-10-07 Kevin J Napier , Matthew J Holman

Intrinsic galaxy alignments yield an important contribution to the observed statistics of galaxy shapes. The general bias expansion for galaxy sizes and shapes in three dimensions has been recently described by Vlah, Chisari \& Schmidt…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-02 Zvonimir Vlah , Nora Elisa Chisari , Fabian Schmidt

The Flexible Image Transport System (FITS) standard has been a great boon to astronomy, allowing observatories, scientists and the public to exchange astronomical information easily. The FITS standard is, however, showing its age. Developed…

We give a complete classification of Riemannian and Lorentzian surfaces of arbitrary codimension in a pseudo-sphere whose pseudo-spherical Gauss maps are of 1-type or, in particular, harmonic. In some cases a concrete global classification…

Differential Geometry · Mathematics 2016-04-25 Burcu Bektaş , Joeri Van der Veken , Luc Vrancken

We present a new approach to measure the shapes of galaxies, a fundamental task in observational astronomy. This approach is based on the decomposition of a galaxy image into a series of orthogonal basis functions, or `shapelets'. Our…

Astrophysics · Physics 2017-08-23 Alexandre Refregier , Tzu-Ching Chang , David Bacon

We describe galaxy surface photometry based on fitting ellipses to the isophotes of the galaxies. Example galaxies with different isophotal shapes are used to illustrate the process, including how the deviations from elliptical isophotes…

Astrophysics · Physics 2018-03-14 Bo Milvang-Jensen , Inger Jorgensen

The Flexible Image Transport System (FITS) standard has been a great boon to astronomy, allowing observatories, scientists and the public to exchange astronomical information easily. The FITS standard, however, is showing its age. Developed…

We present a two-dimensional (2-D) fitting algorithm (GALFIT, Version 3) with new capabilities to study the structural components of galaxies and other astronomical objects in digital images. Our technique improves on previous 2-D fitting…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Chien Y. Peng , Luis C. Ho , Chris D. Impey , Hans-Walter Rix

This survey is devoted to recent developments in the statistical analysis of spherical data, with a view to applications in Cosmology. We will start from a brief discussion of Cosmological questions and motivations, arguing that most…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-28 Javier Carrón Duque , Domenico Marinucci

The growing use of wide angle image capture devices and the need for fast and accurate image analysis in computer visions have enforced the need for dedicated under-representation approaches. Most recent decomposition methods segment an…

Computer Vision and Pattern Recognition · Computer Science 2025-09-25 Rémi Giraud , Rodrigo Borba Pinheiro , Yannick Berthoumieu

When a structure displays dependence on distance and azimuthal angle from a center (for example the spiral arms of galaxies or the diffraction spikes of stars), projecting the pixels to polar coordinates greatly simplifies their study. This…

Instrumentation and Methods for Astrophysics · Physics 2024-06-24 Sepideh Eskandarlou , Mohammad Akhlaghi

Digital co-addition of astronomical images is a common technique for increasing signal-to-noise and image depth. A modification of this simple technique has been applied to the detection of minor bodies in the Solar System: first stationary…

Earth and Planetary Astrophysics · Physics 2015-05-18 Alex H. Parker , JJ. Kavelaars

A spherically symmetric and static metric that describes physical coordinates is introduced. It is defined to be a metric that gives coordinate independent results for physically observable quantities without a further coordinate…

Astrophysics · Physics 2007-05-23 Yukio Tomozawa

The shapelets method for image analysis is based upon the decomposition of localised objects into a series of orthogonal components with convenient mathematical properties. We extend the "Cartesian shapelet" formalism from earlier work, and…

Astrophysics · Physics 2009-11-10 Richard Massey , Alexandre Refregier

A sphere is a fundamental geometric object widely used in (computer aided) geometric design. It possesses rational parameterizations but no parametric polynomial parameterization exists. The present study provides an approach to the optimal…

Numerical Analysis · Mathematics 2021-04-27 Aleš Vavpetič , Emil Žagar

Several local elliptic coordinates are used to build a new polyelliptic coordinate system which is orthogonal and admits the separation of variables. Such coordinate systems can give the exact solutions of some unsolved problems in quantum…

Mathematical Physics · Physics 2014-09-25 Gennady V. Kovalev

We provide a concrete link between celestial amplitudes and cosmological correlators. We first construct a map from quantum field theories (QFTs) in $(D+2)$-dimensional Euclidean space to theories on the $(D+1)$-dimensional sphere, through…

High Energy Physics - Theory · Physics 2025-11-10 Hideo Furugori , Naoki Ogawa , Sotaro Sugishita , Takahiro Waki

In this article, we present a new characterization of the completeness of a partial metric space--which we call \textit{orbital characterization}-- using fixed point results.

General Topology · Mathematics 2019-02-25 Yaé Ulrich Gaba

Complex field measurements are increasingly becoming the standard for state-of-the-art astronomical instrumentation. Complex field measurements have been used to characterize a suite of ground, airborne, and space-based heterodyne receiver…

Instrumentation and Methods for Astrophysics · Physics 2018-09-25 Kristina K. Davis , Willem Jellema , Stephen J. C. Yates , Christopher E. Groppi , Jochem J. A. Baselmans , Andrey M. Baryshev