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Related papers: Cosmic-Ray Rejection by Laplacian Edge Detection

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In this paper we present a new two-level iterative algorithm for tomographic image reconstruction. The algorithm uses a regularization technique, which we call edge-preserving Laplacian, that preserves sharp edges between objects while…

Computer Vision and Pattern Recognition · Computer Science 2015-09-17 Daniil Kazantsev , Evgueni Ovtchinnikov , William R. B. Lionheart , Philip J. Withers , Peter D. Lee

Image Rotation and Subtraction (IRS) is a high-contrast imaging technique which can be used to suppress the speckles noise and facilitate the direct detection of exoplanets. IRS is different from Angular Differential Imaging (ADI), in which…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 Jiangpei Dou , Deqing Ren , Gang Zhao , Xi Zhang , Rui Chen , Yongtian Zhu

A critical analysis and comparison of different methods for obtaining point spread function (PSF) photometry are carried out. Deep ACS observations of NGC3370 were reduced using four distinct approaches. These reductions explore a number of…

Astrophysics of Galaxies · Physics 2023-03-08 In Sung Jang

The existence of cosmic ray particles up to the ultra-high energy limit (> 10^20 eV) is now beyond any doubt. The detection of cosmic particles with such energies imposes a challenge for the comprehension of their sources and nature. On one…

For the light relativistic dark matter (DM) boosted by high energy cosmic ray, its scattering cross section with the nucleon is sensitively dependent on the momentum-transfer and such an dependence is caused by the mediator in the…

High Energy Physics - Phenomenology · Physics 2023-09-04 Wenyu Wang , Wu-Long Xu , Jin Min Yang , Rui Zhu

We perform a blinded cosmology analysis with cosmic shear two-point correlation functions (2PCFs) measured from more than 25 million galaxies in the Hyper Suprime-Cam three-year shear catalog in four tomographic redshift bins ranging from…

Here we present a number of improvements to weak lensing 3D power spectrum analysis, 3D cosmic shear, that uses the shape and redshift information of every galaxy to constrain cosmological parameters. We show how photometric redshift…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 T. D. Kitching , A. F. Heavens , L. Miller

A critical review of the standard paradigm for the origin of Galactic cosmic rays is presented. Recent measurements of local and far-away cosmic rays reveal unexpected behaviours, which challenge the commonly accepted scenario. These recent…

High Energy Astrophysical Phenomena · Physics 2019-11-11 Stefano Gabici , Carmelo Evoli , Daniele Gaggero , Paolo Lipari , Philipp Mertsch , Elena Orlando , Andrew Strong , Andrea Vittino

We present a measurement of cosmic shear on scales ranging from $ 10\arcsec $ to $ 2\arcmin $ in 347 WFPC2 images of random fields. Our result is based on shapes measured via image fitting and on a simple statistical technique; careful…

Astrophysics · Physics 2009-11-10 Stefano Casertano , Kavan U. Ratnatunga , Richard E. Griffiths

This paper presents an introduction to the astrophysics of cosmic rays and diffuse gamma rays and discusses some of the puzzles that have emerged recently due to more precise data and improved propagation models: the excesses in Galactic…

Astrophysics · Physics 2008-11-26 I. V. Moskalenko

Cosmic ray (CR) physics has entered a precision-driven era. With the latest AMS-02 nuclei data (boron-to-carbon ratio, proton flux, helium flux and antiproton-to-proton ratio), we perform a global fitting and constrain the primary source…

High Energy Astrophysical Phenomena · Physics 2018-01-31 Jia-Shu Niu , Tianjun Li

Ridges in galaxy density fields measured by photometric surveys are 2D projections of filaments in the cosmic web, and so should lens light from background galaxies. We report on a detection of this effect in Dark Energy Survey Year 3 data…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-06 Mehraveh Nikjoo , Joe Zuntz , Ben Moews

Cosmic rays are nowadays a crucial tool to study the astrophysics of extreme objects in the Universe, the cosmic environmental plasma (both Galactic and extra-galactic), the physics of nuclear interactions or the properties of elementary…

High Energy Astrophysical Phenomena · Physics 2022-02-16 Pedro de la Torre Luque

Natural image matting, which separates foreground from background, is a very important intermediate step in recent computer vision algorithms. However, it is severely underconstrained and difficult to solve. State-of-the-art approaches…

Computer Vision and Pattern Recognition · Computer Science 2014-04-16 Philip G. Lee , Ying Wu

Space-based X-ray detectors are subject to significant fluxes of charged particles in orbit, notably energetic cosmic ray protons, contributing a significant background. We develop novel machine learning algorithms to detect charged…

Instrumentation and Methods for Astrophysics · Physics 2020-12-04 D. R. Wilkins , S. W. Allen , E. D. Miller , M. Bautz , T. Chattopadhyay , S. Fort , C. E. Grant , S. Herrmann , R. Kraft , R. G. Morris , P. Nulsen

Recently the AMS-02 collaboration has published the measurement of the cosmic antiproton to proton ratio $\bar{p}/p$ and the $\bar{p}$ flux with a high precision up to $\sim 450\,\mathrm{GeV}$. In this work, we perform a systematic analysis…

High Energy Astrophysical Phenomena · Physics 2017-12-27 Su-Jie Lin , Xiao-Jun Bi , Jie Feng , Peng-Fei Yin , Zhao-Huan Yu

The likelihood of detecting individual discrete sources of cosmic rays depends on the mean separation between sources. The analysis here derives the minimum separation that makes it likely that the closest source is detectable. For…

Astrophysics · Physics 2007-08-17 Paul Sommers

We present an algorithm for selecting an uniform sample of gravitationally lensed quasar candidates from low-redshift (0.6<z<2.2) quasars brighter than i=19.1 that have been spectroscopically identified in the SDSS. Our algorithm uses…

The impulsive noise in astronomical images originates from various sources. It develops as a result of thermal generation in pixels, collision of cosmic rays with image sensor or may be induced by high readout voltage in Electron…

Instrumentation and Methods for Astrophysics · Physics 2016-09-28 A. Popowicz , A. R. Kurek , T. Blachowicz , V. Orlov , B. Smolka

Digital radio detection of cosmic-ray air showers has emerged as an alternative technique in high-energy astroparticle physics. Estimation of the detection efficiency of cosmic-ray radio arrays is one of the few remaining challenges…

Instrumentation and Methods for Astrophysics · Physics 2023-06-28 Vladimir Lenok , Frank G. Schröder