English
Related papers

Related papers: Measuring angular diameters of extended sources - …

200 papers

We investigate through dedicated numerical simulations the evolution of the soft X-ray absorption properties of a cloud surrounding a gamma-ray burst source. We show that the absorption properties of the material are strongly modified by…

Astrophysics · Physics 2009-11-07 Davide Lazzati , Rosalba Perna

Gravitational waves propagate along null geodesics like light rays in the geometrical optics approximation, and they may have a chance to suffer from gravitational lensing by intervening objects, as is the case for electromagnetic waves.…

General Relativity and Quantum Cosmology · Physics 2010-10-12 Yousuke Itoh , Toshifumi Futamase , Makoto Hattori

Non-Gaussianities of dynamical origin are disentangled from primordial ones using the formalism of large deviation statistics with spherical collapse dynamics. This is achieved by relying on accurate analytical predictions for the one-point…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Cora Uhlemann , Enrico Pajer , Christophe Pichon , Takahiro Nishimichi , Sandrine Codis , Francis Bernardeau

We present a multi-scale, multi-wavelength source extraction algorithm called getsources. Although it has been designed primarily for use in the far-infrared surveys of Galactic star-forming regions with Herschel, the method can be applied…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 A. Men'shchikov , Ph. André , P. Didelon , F. Motte , M. Hennemann , N. Schneider

The gravitational lensing of gravitational waves should be treated in the wave optics instead of the geometrical optics when the wave length $\lambda$ of the gravitational waves is larger than the Schwarzschild radius of the lens mass $M$.…

Astrophysics · Physics 2009-11-10 Ryuichi Takahashi

For over a century diffraction theory has been thought to limit the resolution of focusing and imaging in the optical domain. The size of the smallest spot achievable is inversely proportional to the range of spatial wavevectors available.…

Optics · Physics 2011-01-11 Michael Mazilu , Joerg Baumgartl , Kishan Dholakia

The nature of dark matter and dark energy are among the central questions in cosmology. Strong gravitational lenses with multiple source planes provide a geometric probe of cosmology: the ratio of deflection angles at different redshifts…

Weak gravitational lensing from large-scale structure enhances and reduces the fluxes from extragalactic point sources with an rms amplitude of order 15%. In cosmic microwave background (CMB) experiments, sources exceeding some flux…

Astrophysics · Physics 2015-06-24 Max Tegmark , Jens Villumsen

Context. Observations of the effect of microlensing in gravitationally lensed quasars could potentially be used to study the structure of the source on distance scales down to the size of the supermassive black hole powering the quasar…

High Energy Astrophysical Phenomena · Physics 2016-02-17 Ievgen Vovk , Andrii Neronov

Precise modeling of extended sources is a central challenge in modern optical engineering, laser physics, and computational lithography. Unlike ideal point sources or completely incoherent thermal radiation sources, real-world light sources…

Optics · Physics 2025-12-09 Rongqi Shang , Donglin Ma

We use Monte Carlo simulations to investigate the theory of galaxy-galaxy lensing by non-spherical dark matter haloes. The simulations include a careful accounting of the effects of multiple deflections. In a typical data set where the mean…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Paul J. Howell , Tereasa G. Brainerd

The Galactic gamma-ray flux can be described as the sum of two components: the first is due to the emission from an ensemble of discrete sources, and the second is formed by the photons produced by cosmic rays propagating in interstellar…

High Energy Astrophysical Phenomena · Physics 2024-12-13 Paolo Lipari , Silvia Vernetto

We show that the usual relation between redshift and angular-diameter distance can be obtained by considering light from a source to be gravitationally lensed by material that lies in the telescope beam as it passes from source to observer…

Astrophysics · Physics 2008-02-03 Fedja Hadrovic , James Binney

In this paper we analyze the image formation problem for undulator radiation through an optical system, accounting for the influence of the electron beam emittance. On the one hand, image formation with Synchrotron Radiation is governed by…

Accelerator Physics · Physics 2009-09-29 Gianluca Geloni , Evgeni Saldin , Evgeni Schneidmiller , Mikhail Yurkov

Skymaps measured with imaging atmospheric Cherenkov telescopes (IACTs) represent the real source distribution convolved with the point spread function of the observing instrument. Current IACTs have an angular resolution in the order of…

Instrumentation and Methods for Astrophysics · Physics 2015-08-26 Susanne Raab , Ira Jung-Richardt

In this work, Bayesian inversion with global-local forwards models is used to identify the parameters based on hydraulic fractures in porous media. It is well-known that using Bayesian inversion to identify material parameters is…

Numerical Analysis · Mathematics 2023-04-11 Nima Noii , Thomas Wick , Amirreza Khodadadian

Two approaches (micro- and macro- investigations) are used to determine the dimension dependences of the optical parameters of the nanometer-scale layers of materials. It is shown that both an index of refraction and coefficient of…

Materials Science · Physics 2016-10-13 T. A. Kudykina , A. I. Pervak

The imaging performance of tomographic deconvolution phase microscopy can be described in terms of the phase optical transfer function (POTF) which, in turn, depends on the illumination profile. To facilitate the optimization of the…

Optics · Physics 2021-05-12 Jianhui Huang , Yijun Bao , Thomas K. Gaylord

In this article we recover the distribution function (and possible density) of an arbitrary random variable that is subject to an additive measurement error. This problem is also known as deconvolution and has a long tradition in…

Statistics Theory · Mathematics 2025-10-07 Henrik Kaiser

A fraction of the XMM-Newton/EPIC FOV is obscured by the dysfunctional (i.e. bad) pixels. The fraction varies between different EPIC instruments in a given observation. These complications affect the analysis of extended X-ray sources…

Instrumentation and Methods for Astrophysics · Physics 2021-03-03 J. Nevalainen , I. Valtchahov , R. D. Saxton , S. Molendi