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The detection reliability of weak signals is a critical issue in many astronomical contexts and may have severe consequences for determining number counts and luminosity functions, but also for optimising the use of telescope time in…

Instrumentation and Methods for Astrophysics · Physics 2016-04-06 Roberto Vio , Paola Andreani

We describe a process for cross-calibrating the effective areas of X-ray telescopes that observe common targets. The targets are not assumed to be "standard candles" in the classic sense, in that we assume that the source fluxes have…

Instrumentation and Methods for Astrophysics · Physics 2021-12-01 Herman L. Marshall , Yang Chen , Jeremy J. Drake , Matteo Guainazzi , Vinay L. Kashyap , Xiao-Li Meng , Paul P. Plucinsky , Peter Ratzlaff , David A. van Dyk , Xufei Wang

This paper presents the basic principle and theoretical relationships of an original method allowing to retrieve the Wavefront Errors (WFE) of a ground or space-borne telescope when combining its main pupil with a second, decentered…

Optics · Physics 2011-05-19 Francois Henault

We consider fully discrete schemes based on the scalar auxiliary variable (SAV) approach and stabilized SAV approach in time and the Fourier-spectral method in space for the phase field crystal (PFC) equation. Unconditionally energy…

Analysis of PDEs · Mathematics 2019-07-18 Xiaoli Li , Jie Shen

The idea of using stellar photometry for atmospheric monitoring for optical experiments in high-energy astrophysics is seemingly straightforward, but reaching high precision of the order of 0.01 in the determination of the vertical aerosol…

In this work, the force due to radiation pressure is measured with sub-10 pN sensitivity, corresponding to less than 2 mW of optical power. The apparatus adds homemade reflectors to a commercial Cavendish balance, which consists of a…

Physics Education · Physics 2026-01-22 Leland Russell , Ezekiel A. Rein , Anatalya Piatigorsky , Jennifer T. Heath

Traction Force Microscopy (TFM) computes the forces exerted at the surface of an elastic material by measuring induced deformations in volume. It is used to determine the pattern of the adhesion forces exerted by cells or by cellular…

Biological Physics · Physics 2018-02-09 Stanislav Makarchuk , Nicolas Beyer , Christian Gaiddon , Wilfried Grange , Pascal Hébraud

We show star images obtained with a miniature ``densified pupil imaging interferometer'' also called a hyper-telescope. The formation of such images violates a ``golden rule of imaging interferometers'' which appeared to forbid the use of…

Astrophysics · Physics 2009-10-31 E. Pedretti , A. Labeyrie , L. Arnold , N. Thureau , O. Lardiere , A. Boccaletti , P. Riaud

The pointing system of the prototype of the Large Size Telescope (LST-1) for the Cherenkov Telescope Array observatory, should ensure mapping of the gamma-ray image of a point-like source in the Cherenkov camera to the sky coordinates with…

Instrumentation and Methods for Astrophysics · Physics 2019-08-06 Darko Zarić , Stefan Cikota , Armand Fiasson , Nikola Godinović , Koji Noda , Robert Wagner , Martin Will , Quentin Piel

Images taken by space telescopes typically have a superb spatial resolution, but a relatively poor sampling rate due to the finite CCD pixel size. Beyond the Nyquist limit, it becomes uncertain how much the pixelation effect may affect the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-06 Zhi Shen , Jun Zhang , Hekun Li , Haoran Wang , Chengliang Wei , Guoliang Li , Xiaobo Li , Zhang Ban , Dan Yue

The familiar tools of Fourier analysis and Fisher matrices are applied to derive the uncertainties on photometric, astrometric, and weak-lensing measurements of stars and galaxies in real astronomical images. Many effects or functions that…

Astrophysics · Physics 2007-05-23 Gary Bernstein

With sub-microarcsecond angular accuracy, the \theia telescope will be capable of revealing the architectures of nearby exoplanetary systems down to the mass of Earth. This research addresses the challenges inherent in space astrometry…

Instrumentation and Methods for Astrophysics · Physics 2024-08-29 F. Malbet , M. Lizzana , F. Pancher , S. Soler , A. Léger , T. Lépine , G. A. Mamon , A. Sozzetti , A. Riva , D. Busonero , L. Labadie , P. -O. Lagage , R. Goullioud

We demonstrate an optical frequency analysis method using the Fourier transform of detection times of fluorescence photons emitted from a single trapped 40Ca+ ion. The response of the detected photon rate to the relative laser frequency…

A new technique for reliably identifying point sources in millimeter/sub-millimeter wavelength maps is presented. This method accounts for the frequency dependence of noise in the Fourier domain as well as non-uniformities in the coverage…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 T. A. Perera , G. W. Wilson , K. S. Scott , J. E. Austermann , J. R. Schaar , A. Mancera

The last 20 years have seen the development of new techniques in Astroparticle Physics providing access to the highest end of the electromagnetic spectrum. It has been shown that some sources emit photons up to energies close to 100 TeV.…

High Energy Astrophysical Phenomena · Physics 2015-08-04 J. L. Contreras , J. Rosado , F. Arqueros , M. López , J. A. Barrio , M. Nievas

We report a method to design at will the spatial profile of transmitted coherent light after propagation through a scattering sample. We compute an operator based on the experimentally measured transmission matrix, obtained by numerically…

Image computation is a fundamental tool for performance assessment of astronomical instrumentation, usually implemented by Fourier transform techniques. We review the numerical implementation, evaluating a direct implementation of the…

Astrophysics · Physics 2008-11-26 M. Gai , R. Cancelliere

We demonstrate highly accurate recovery of weak gravitational lensing shear using an implementation of the Bayesian Fourier Domain (BFD) method proposed by Bernstein & Armstrong (2014, BA14), extended to correct for selection biases. The…

Instrumentation and Methods for Astrophysics · Physics 2016-04-28 Gary M. Bernstein , Robert Armstrong , Christina Krawiec , Marisa C. March

This paper proposes a method for estimating and detecting optical signals in practical photon-counting receivers. There are two important aspects of non-perfect photon-counting receivers, namely, (i) dead time which results in blocking…

Signal Processing · Electrical Eng. & Systems 2024-08-21 Chen Wang , Zhiyong Xu , Jingyuan Wang , Jianhua Li , Weifeng Mou , Huatao Zhu , Jiyong Zhao , Yang Su , Yimin Wang , Ailin Qi

We use automated surface photometry and pattern classification techniques to morphologically classify galaxies. The two-dimensional light distribution of a galaxy is reconstructed using Fourier series fits to azimuthal profiles computed in…

Astrophysics · Physics 2009-11-07 S. C. Odewahn , S. H. Cohen , R. A. Windhorst , N. S. Philip